Astrophysics
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New submissions for Tue, 26 May 20
- [1] arXiv:2005.11316 [pdf, ps, other]
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Title: On the radial acceleration of disk galaxiesComments: 13 Pages, 13 Figures, and 02 Tables; Author's corrected versionJournal-ref: Monthly Notices Roy. Astron. Soc 494, pages 4015-4025 (2020)Subjects: Astrophysics of Galaxies (astro-ph.GA)
The physical processes defining the dynamics of disk galaxies are still poorly understood. Hundreds of articles have appeared in the literature over the last decades without arriving at an understanding within a consistent gravitational theory. Dark matter (DM) scenarios or a modification of Newtonian dynamics (MOND) are employed to model the non-Keplerian rotation curves in most of the studies, but the nature of DM and its interaction with baryonic matter remains an open question and MOND formulates a mathematical concept without a physical process. We have continued our attempts to use the impact theory of gravitation for a description of the peculiar acceleration and velocity curves and have considered five more galaxies. Using published data of the galaxies NGC 3198, NGC 2403, NGC 1090, UGC 3205 and NGC 1705, it has been possible to find good fits without DM for the observed disk velocities and, as example, also for the extraplanar matter of NGC 3198.
- [2] arXiv:2005.11325 [pdf, other]
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Title: Thermalization of large energy release in the early UniverseComments: 22 pages, 19 figures, submitted to MNRAS, comments welcome!Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
Spectral distortions of the cosmic microwave background (CMB) provide a unique tool for learning about the early phases of cosmic history, reaching deep into the primordial Universe. At redshifts $z<10^6$, thermalization processes become inefficient and existing limits from COBE/FIRAS imply that no more than $\Delta \rho/\rho<6\times 10^{-5}$ (95% c.l.) of energy could have been injected into the CMB. However, at higher redshifts, when thermalization is efficient, the constraint weakens and $\Delta \rho/\rho \simeq 0.01-0.1$ could in principle have occurred. Existing computations for the evolution of distortions commonly assume $\Delta \rho/\rho \ll 1$ and thus become inaccurate in this case. Similarly, relativistic temperature corrections become relevant for large energy release, but have previously not been modeled as carefully. Here we study the evolution of distortions and the thermalization process after single large energy release at $z>10^5$. We show that for large distortions the thermalization efficiency is significantly reduced and that the distortion visibility is sizeable to much earlier times. This tightens spectral distortions constraints on low-mass primordial black holes with masses $M_{\rm PBH} < 6\times 10^{11}$ g. Similarly, distortion limits on the amplitude of the small-scale curvature power spectrum at wavenumbers $k>10^4\,{\rm Mpc}^{-1}$ and short-lived decaying particles with lifetimes $t_X< 10^7$ s are tightened, however, these require a more detailed time-dependent treatment. We also briefly discuss the constraints from measurements of the effective number of relativistic degrees of freedom and light element abundances and how these complement spectral distortion limits.
- [3] arXiv:2005.11326 [pdf, other]
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Title: Quantifying Density-Ionization Correlations with the 21cm Power SpectrumComments: 11 pages, 9 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The Epoch of Reionization (EoR)---when neutral hydrogen in the intergalactic medium was systematically ionized---is a period in our Universe's history that is currently poorly understood. However, a key prediction of most models is a correlation between the density and ionization field during the EoR. This has consequences for the 21cm power spectrum. Here, we propose a parametrization for the density-ionization correlation and study the dependence of the 21cm power spectrum on this parameterization. We use this formalism to forecast the ability of current and future observations to constrain these correlations. We find that upper limits on the dimensionless power spectrum at redshifts $7.5 < z < 8.5$ using $k$ bins between $0.1\,\textrm{Mpc}^{-1} < k < 0.75\,\textrm{Mpc}^{-1}$ with error bars at the level of $\sim\!\!20\,\textrm{mK}^2$ about our fiducial model would rule out uncorrelated reionization at $99\%$ credibility. Beyond upper limits, we find that at its full sensitivity, the Hydrogen Epoch of Reionization Array (HERA) will be able to place strong constraints on the sign and magnitude of density-ionization correlations.
- [4] arXiv:2005.11330 [pdf, other]
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Title: Observed sizes of planet-forming disks trace viscous evolutionComments: 19 pages, 17 figures, accepted in A&ASubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA)
The evolution of protoplanetary disks is dominated by the conservation of angular momentum, where the accretion of material onto the central star is driven by viscous expansion of the outer disk or by disk winds extracting angular momentum without changing the disk size. Studying the time evolution of disk sizes allows us therefore to distinguish between viscous stresses or disk winds as the main mechanism of disk evolution. Observationally, estimates of the disk gaseous outer radius are based on the extent of the CO rotational emission, which, during the evolution, is also affected by the changing physical and chemical conditions in the disk. We use physical-chemical DALI models to study how the extent of the CO emission changes with time in a viscously expanding disk and investigate to what degree this observable gas outer radius is a suitable tracer of viscous spreading and whether current observations are consistent with viscous evolution. We find that the gas outer radius (R_co) measured from our models matches the expectations of a viscously spreading disk: R_co increases with time and for a given time R_co is larger for a disk with a higher viscosity alpha_visc. However, in the extreme case where the disk mass is low (less than 10^-4 Msun) and alpha_visc is high (larger than 10^-2), R_co will instead decrease with time as a result of CO photodissociation in the outer disk. For most disk ages R_co is up to 12x larger than the characteristic size R_c of the disk, and R_co/R_c is largest for the most massive disk. As a result of this difference, a simple conversion of R_co to alpha_visc will overestimate the true alpha_visc of the disk by up to an order of magnitude. We find that most observed gas outer radii in Lupus can be explained using a viscously evolving disk that starts out small (R_c = 10 AU) and has a low viscosity (alpha_visc = 10^-4 - 10^-3).
- [5] arXiv:2005.11331 [pdf, other]
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Title: Highlights of Exoplanetary Science from SpitzerComments: Invited review for Nature AstronomySubjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Observations of extrasolar planets were not projected to be a significant part of the Spitzer Space Telescope's mission when it was conceived and designed. Nevertheless, Spitzer was the first facility to detect thermal emission from a hot Jupiter, and the range of Spitzer's exoplanetary investigations grew to encompass transiting planets, microlensing, brown dwarfs, and direct imaging searches and astrometry. Spitzer used phase curves to measure the longitudinal distribution of heat as well as time-dependent heating on hot Jupiters. Spitzer's secondary eclipse observations strongly constrained the dayside thermal emission spectra and corresponding atmospheric compositions of hot Jupiters, and the timings of eclipses were used for studies of orbital dynamics. Spitzer's sensitivity to carbon-based molecules such as methane and carbon monoxide was key to atmospheric composition studies of transiting exoplanets as well as imaging spectroscopy of brown dwarfs, and complemented Hubble spectroscopy at shorter wavelengths. Spitzer's capability for long continuous observing sequences enabled searches for new transiting planets around cool stars, and helped to define the architectures of planetary systems like TRAPPIST-1. Spitzer measured masses for small planets at large orbital distances using microlensing parallax. Spitzer observations of brown dwarfs probed their temperatures, masses, and weather patterns. Imaging and astrometry from Spitzer was used to discover new planetary mass brown dwarfs and to measure distances and space densities of many others.
- [6] arXiv:2005.11333 [pdf, other]
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Title: Evolution of gas disc-embedded intermediate mass ratio inspirals in the LISA bandComments: 18 pages, 15 figures, submitted to MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA)
Among the potential gravitational wave (GW) sources for the upcoming space-based interferometer LISA are extreme- or intermediate-mass ratio inspirals (EMRI/IMRIs). These events involve the coalescence of supermassive black holes in the mass range $10^5M_{\odot}\lesssim M \lesssim 10^7M_{\odot}$ with companion BHs of much lower masses. A subset of E/IMRIs are expected to occur in the accretion discs of active galactic nuclei (AGN). Previous work has shown that torques exerted by the disc can interfere with the inspiral and cause a phase shift in the GW waveform detectable by LISA. Here we use a suite of two-dimensional hydrodynamical simulations with the moving-mesh code DISCO to present a systematic study of disc torques. We measure torques on an inspiraling BH and compute the corresponding waveform deviations as a function of the binary mass ratio $q\equiv M_2/M_1$, the disc viscosity ($\alpha$), and gas temperature (or equivalently Mach number; $\mathcal{M}$). We find that the absolute value of the gas torques is within an order of magnitude of previously determined planetary migration torques, but their precise value and sign depends non-trivially on the combination of these parameters, the inspiral rate, and the accretion rate onto the satellite BH. The gas imprint is generally detectable by LISA for binaries embedded in AGN discs with surface densities above $\Sigma_0\ge10^{4-6} \rm \, g \, cm^{-2}$, depending on $q$, $\alpha$ and $\mathcal{M}$. We find that the deviations are most pronounced in discs with higher viscosities, and for E/IMRIs detected at frequencies where LISA is most sensitive. Torques in colder discs exhibit a noticeable dependence on the GW-driven inspiral rate as well as strong fluctuations at late stages of the inspiral. Our results further suggest that LISA may be able to place constraints on AGN disc parameters and the physics of disc-satellite interaction.
- [7] arXiv:2005.11345 [pdf, other]
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Title: Spectral analysis of the quiescent low-mass X-ray binary in the globular cluster M30Authors: Constanza Echiburú, Sebastien Guillot, Yue Zhao, Craig O. Heike, Feryal Özel, Natalie A. WebbComments: accepted for publication in MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We present a recent Chandra observation of the quiescent low-mass X-ray binary containing a neutron star, located in the globular cluster M30. We fit the thermal emission from the neutron star to extract its mass and radius. We find no evidence of flux variability between the two observations taken in 2001 and 2017, nor between individual 2017 observations, so we analyse them together to increase the signal to noise. We perform simultaneous spectral fits using standard light-element composition atmosphere models (hydrogen or helium), including absorption by the interstellar medium, correction for pile-up of X-ray photons on the detector, and a power-law for count excesses at high photon energy. Using a Markov-chain Monte Carlo approach, we extract mass and radius credible intervals for both chemical compositions of the atmosphere: $R_{\textrm{NS}}=7.94^{+0.76}_{-1.21}$ km and $M_{\textrm{NS}}<1.19$ M$_{\odot}$ assuming pure hydrogen, and $R_{\textrm{NS}}=10.50^{+2.88}_{-2.03}$ km and $M_{\textrm{NS}}<1.78$ M$_{\odot}$ for helium, where the uncertainties represent the 90% credible regions. For H, the small radius is difficult to reconcile with most current nuclear physics models (especially for nucleonic equations of state) and with other measurements of neutron star radii, with recent preferred values generally in the 11-14 km range. Whereas for He, the measured radius is consistent with this range. We discuss possible sources of systematic uncertainty that may result in an underestimation of the radius, identifying the presence of surface temperature inhomogeneities as the most relevant bias. According to this, we conclude that either the atmosphere is composed of He, or it is a H atmosphere with a significant contribution of hot spots to the observed radiation.
- [8] arXiv:2005.11352 [pdf, other]
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Title: A Data-Driven Approach for Extraction of Event-Waveform: Application to Gravitational WavesComments: 5 pages, 3 figuresSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
In the light of the importance of gravitational waves in astronomy, it is essential to perform independent \textit{data analysis} compared to the approach used by the LIGO team. To address this, here we develop a general data-driven, template-free {\it noise suppression method}, for extraction of the event-waveform. Using the developed method, we obtain waveforms of all reported events by LIGO. In addition, using instantaneous frequencies (derived by Hilbert transform) of the extracted waveforms, we provide the time delays between the arrival of gravitational waves to the detectors.
- [9] arXiv:2005.11363 [pdf]
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Title: A Catalog of Prominence Eruptions Detected Automatically in the SDO/AIA 304 Å ImagesAuthors: S. Yashiro (1 and 2), N. Gopalswamy (2), S. Akiyama (1 and 2), P.A. Mäkelä (1 and 2) ((1) Catholic University of America, (2) NASA/GSFC)Comments: 22 pages, 9 figuresSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
We report on a statistical study of prominence eruptions (PEs) using a catalog of these events routinely imaged by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) in the 304 \r{A} pass band. Using an algorithm developed as part of an LWS project, we have detected PEs in 304 \r{A} synoptic images with 2-min cadence since May 2010. A catalog of these PEs is made available online (https://cdaw.gsfc.nasa.gov/CME_list/autope/). The 304 \r{A} images are polar-transformed and divided by a background map (pixels with minimum intensity during one day) to get the ratio maps above the limb. The prominence regions are defined as pixels with a ratio $\ge$2. Two prominence regions with more than 50% of pixels overlapping are considered the same prominence. If the height of a prominence increases monotonically in 5 successive images, it is considered eruptive. All the PEs seen above the limb are detected by the routine, but only PEs with width $\ge$15{\deg} are included in the catalog to eliminate polar jets and other small-scale mass motions. The identifications are also cross-checked with the PEs identified in Nobeyama Radioheliograph images (this http URL). The catalog gives the date, time, central position angle, latitude, and width of the eruptive prominence. The catalog also provides links to JavaScript movies that combine SDO/AIA images with GOES soft X-ray data to identify the associated flares, and with SOHO/LASCO C2 images to identify the associated coronal mass ejections. We examined the statistical properties of the PEs and found that the high-latitude PE speed decreased with the decreasing of the average polar magnetic field strength of the previous cycle.
- [10] arXiv:2005.11372 [pdf, other]
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Title: The Galactic radial abundance gradients of C, N, O, Ne, S, Cl and Ar from deep spectra of H II regionsComments: 26 pages, 12 figures. Accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
We present a reassessment of the radial abundance gradients of C, N, O, Ne, S, Cl and Ar in the Milky Way using deep spectra of 33 H II regions gathered from the literature, covering Galactocentric distances from 6 to 17 kpc. The distances of the objects have been revised using Gaia parallaxes. We recalculate the physical conditions and ionic abundances in an homogeneous way using updated atomic data. All the objects have direct determination of the electron temperature, permitting to derive their precise ionic abundances. We analyze and compare different ICF schemes for each element in order to obtain the most confident total abundances. Due to the revised distances, our results do not support previous claims about a possible flattening of the O/H gradient in the inner Galactic disk. We find that the Galactic N/O gradient is rather flat, in contrast to what has been found in other spiral galaxies. The slope of the gradients of some elements is sensitive to the ICF scheme used, especially in the case of Ne. The dispersion around the fit for the gradients of C, N, O, S, Cl and Ar is of the order of the typical uncertainties in the determination of the abundances, implying the absence of significant inhomogeneities in the chemical composition of the ionized gas phase of the ISM. We find flat gradients of log(S/O) and log(Cl/O) and very shallow or flat ones for log(Ne/O) and log(Ar/O), consistent with a lockstep evolution of Ne, S, Cl and Ar with respect to O.
- [11] arXiv:2005.11403 [pdf, other]
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Title: A high-resolution view of the jets in 3C 465Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We present new high-resolution and high-sensitivity studies of the jets in the WAT source 3C 465, using deep transverse-resolved radio observations from e-MERLIN, and with complementary observations from the VLA. We derive a lower limit $\beta_{\rm j}$ = ($\nu_{\rm j}$/$c$) $\gtrsim$ 0.5 for the jet speed, and an upper limit $\theta_{\rm j}$ $\lesssim$ 61$^{\circ}$ for the jet angle to the line of sight. The jet spectral index ($\alpha$, defined in the sense $S \propto \nu^{\alpha}$) is fairly constant (<$\alpha_{\rm jet}$> = $-$0.7), and spectral flattening within 4.4 kpc of the core coincides with bright knots and is consistent with the site of X-ray particle acceleration at the base of the radio jet found in previous studies. There is little difference between the spectra of the two hotspot components, plausibly indicating that electron populations of the same properties are injected there. The NW and SE plumes are approximately homologous structures, with variations in mass injection and propagation in external pressure and density gradients in the two regions plausibly accounting for the slightly steeper spectrum in the NW plume, <$\alpha_{\rm NWp}$> = $-$1.43 compared with the SE plume, <$\alpha_{\rm SEp}$> = $-$1.38. Our synchrotron lifetime model supports plausible reacceleration of particles within the plume materials. Overall, our results show that the first-order Fermi process at mildly relativistic and non-relativistic shocks is the most likely acceleration mechanism at play in 3C 465 and distinguish differences between the acceleration at $\beta_{\rm j}$ $>$ 0.5 and $\beta_{\rm j}$ $<$ 0.5. The former case can accelerate electrons to higher Lorentz factors.
- [12] arXiv:2005.11449 [pdf, ps, other]
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Title: Binary evolution leading to the formation of the very massive neutron star in the J0740+6620 binary systemComments: 7 pages, 8 figures. Accepted for publication in MNRASSubjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)
We study the evolution of close binary systems in order to account for the existence of the recently observed binary system containing the most massive millisecond pulsar ever detected, PSR J0740+6620, and its ultra-cool helium white dwarf companion. In order to find a progenitor for this object we compute the evolution of several binary systems composed by a neutron star and a normal donor star employing our stellar code. We assume conservative mass transfer. We also explore the effects of irradiation feedback on the system. We find that irradiated models also provide adequate models for the millisecond pulsar and its companion, so both irradiated and non irradiated systems are good progenitors for PSR J0740+6620. Finally, we obtain a binary system that evolves and accounts for the observational data of the system composed by PSR J0740+6620 (i.e. orbital period, mass, effective temperature and inferred metallicity of the companion, and mass of the neutron star) in a time scale smaller than the age of the Universe. In order to reach an effective temperature as low as observed, the donor star should have an helium envelope as demanded by observations.
- [13] arXiv:2005.11469 [pdf, other]
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Title: Shapes and alignments of dark matter haloes and their brightest cluster galaxies in 39 strong lensing clustersAuthors: Taizo Okabe, Masamune Oguri, Sébastien Peirani, Yasushi Suto, Yohan Dubois, Christophe Pichon, Tetsu Kitayama, Shin Sasaki, Takahiro NishimichiComments: 18 pages, 16 figures, 6 Tables, accepted by MNRASSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)
We study shapes and alignments of 45 dark matter (DM) haloes and their brightest cluster galaxies (BCGs) using a sample of 39 massive clusters from Hubble Frontier Field (HFF), Cluster Lensing And Supernova survey with Hubble (CLASH), and Reionization Lensing Cluster Survey (RELICS). We measure shapes of the DM haloes by strong gravitational lensing, whereas BCG shapes are derived from their light profiles in Hubble Space Telescope images. Our measurements from a large sample of massive clusters presented here provide new constraints on dark matter and cluster astrophysics. We find that DM haloes are on average highly elongated with the mean ellipticity of $0.482\pm 0.028$, and position angles of major axes of DM haloes and their BCGs tend to be aligned well with the mean value of alignment angles of $22.2\pm 3.9$ deg. We find that DM haloes in our sample are on average more elongated than their BCGs with the mean difference of their ellipticities of $0.11\pm 0.03$. In contrast, the Horizon-AGN cosmological hydrodynamical simulation predicts on average similar ellipticities between DM haloes and their central galaxies. While such a difference between the observations and the simulation may well be explained by the difference of their halo mass scales, other possibilities include the bias inherent to strong lensing measurements, limited knowledge of baryon physics, or a limitation of cold dark matter.
- [14] arXiv:2005.11479 [pdf, other]
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Title: Stringent upper limits on pulsed radio emission during an active bursting phase of the Galactic magnetar SGRJ1935+2154Authors: L. Lin, C. F. Zhang, P. Wang, H. Gao, X. Guan, J. L. Han, J. C. Jiang, P. Jiang, K. J. Lee, D. Li, Y. P. Men, C. C. Miao, C. H. Niu, J. R. Niu, C. Sun, B. J. Wang, Z. L. Wang, H. Xu, J. L. Xu, J. W. Xu, Y. H. Yang, Y. P. Yang, W. Yu, B. Zhang, B.-B. Zhang, D. J. Zhou, W. W. Zhu, A. J. Castro-Tirado, Z. G. Dai, M. Y. Ge, Y. D. Hu, C. K. Li, Y. Li, Z. Li, E. W. Liang, S. M. Jia, R. Querel, L. Shao, F. Y. Wang, X. G. Wang, X. F. Wu, S. L. Xiong, R. X. Xu, Y.-S. Yang, G. Q. Zhang, S. N. Zhang, T. C. Zheng, J.-H. ZouComments: 28 pages, 7 figures, submittedSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Fast radio bursts (FRBs) are mysterious millisecond-duration radio transients observed from extragalactic distances. Magnetars have been long speculated as the possible engine to power repeating bursts from FRB sources, but no convincing evidence has been collected so far. Recently, a Galactic magnetar dubbed Soft Gamma-ray Repeater (SGR) J1935+2154 entered an active phase by emitting intense soft gamma-ray bursts}. One fast radio burst with two peaks (hereafter FRB 200428) and a luminosity comparable to those of extragalactic FRBs was detected from the source in association with a soft $\gamma$-ray / hard X-ray flare. Here we report an eight-hour targeted observational campaign with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in four observing sessions, assisted by multi-wavelength (optical and hard X-rays) observations. During the third session, twenty-nine SGR bursts were detected by the {\it Fermi} Gamma-ray Burst Monitor (GBM). Throughout the observing period, especially during the scrutinized epochs when SGR bursts reached the Earth, no single dispersed pulsed emission was detected by FAST. This places a fluence upper limit eight orders of magnitude deeper than the fluence of FRB 200428. Our results suggest that FRB -- SGR burst associations are rather rare. FRBs may be highly relativistic and geometrically beamed or may carry narrow spectra with the characteristic frequencies of the most bursts far outside the FAST band. More intriguingly, it is also possible that the physical condition to achieve coherent radiation in SGR bursts is contrived. Only under extreme conditions could an FRB be made in association with an SGR burst.
- [15] arXiv:2005.11535 [pdf, ps, other]
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Title: Jet Properties of Compact Steep-Spectrum Sources and an Eddington-Ratio-Driven Unification Scheme of Jet Radiation in Active Galactic NucleiAuthors: Jin Zhang (NAOC), Hai-Ming Zhang (NJU), Ying-Ying Gan (GXU), Ting-Feng Yi (YNNU), Jun-Feng Wang (XMU), En-Wei Liang (GXU)Comments: 37 Pages, 11 Figures, 4 Tables, Comments are WelcomeSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Compact steep-spectrum sources (CSSs) likely represent a population of young radio-loud active galactic nuclei (AGNs). Six CSSs have been identified as gamma-ray emitting sources. We present a comprehensive analysis of their gamma-ray emission observed with Fermi/LAT and establish their broadband spectral energy distributions (SEDs). We derive their jet properties by the SED fits with a two-zone leptonic model for radiations from the compact core and large-scale extended region, and explore the possible signature of a unification picture of jet radiation among subclasses of AGNs. We show that the observed gamma-rays of CSSs with significant variability are contributed by the radiation of their compact cores via the inverse Compton process of the torus photons. The derived power-law distribution index of the radiating electrons is p_1~1.5-1.8, magnetic field strength is B~0.15-0.6 G, and Doppler boosting factor is \delta~2.8-8.9. Assuming that the jet is composed of electron-positron pairs, the compact cores of CSSs are magnetized and have a high radiation efficiency, similar to that of flat spectrum radio quasars. The six CSSs on average have higher Eddington ratio and black hole mass than those non-GeV-detected CSSs, and they follow the correlation between the jet power in units of Eddington luminosity (P_jet/L_Edd) and Eddington ratio (R_Edd) with other sub-classes of AGNs, P_jet/L_Edd~R_Edd^0.52, indicating that R_Edd would be a key physical driver for the unification scheme of AGN jet radiation.
- [16] arXiv:2005.11537 [pdf, ps, other]
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Title: Gaia 18dvy: a new FUor in the Cygnus OB3 associationAuthors: E. Szegedi-Elek, P. Ábrahám, L. Wyrzykowski, M. Kun, A. Kóspál, L. Chen, G. Marton, A. Moór, Cs. Kiss, A. Pál, L. Szabados, J. Varga, E. Varga-Verebélyi, C. Andreas, E. Bachelet, R. Bischoff, A. Bódi, E. Breedt, U. Burgaz, T. Butterley, V. Čepas, G. Damljanovic, I. Gezer, V. Godunova, M. Gromadzki, A. Gurgul, L. Hardy, F. Hildebrandt, S. Hoffmann, M. Hundertmark, N. Ihanec, R. Janulis, Cs. Kalup, Z. Kaczmarek, R. Könyves-Tóth, M. Krezinger, K. Kruszyńska, S. Littlefair, M. Maskoliūnas, L. Mészáros, P. Mikołajczyk, M. Mugrauer, H. Netzel, A. Ordasi, E. Pakštienė, K. A. Rybicki, K. Sárneczky, B. Seli, A. Simon, K. Šiškauskaitė, Á. Sódor, K. V. Sokolovsky, W. Stenglein, et al. (9 additional authors not shown)Comments: 11 pages, 7 figures, accepted for publication in ApJSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
We present optical-infrared photometric and spectroscopic observations of Gaia18dvy, located in the Cygnus OB3 association at a distance of 1.88 kpc. The object was noted by the Gaia alerts system when its lightcurve exhibited a $\gtrsim$4 mag rise in 2018-2019. The brightening was also observable at mid-infared wavelengths. The infrared colors of Gaia18dvy became bluer as the outburst progressed. Its optical and near-infrared spectroscopic characteristics in the outburst phase are consistent with those of bona fide FU Orionis-type young eruptive stars. The progenitor of the outburst is probably a low-mass K-type star with an optical extinction of $\sim$3 mag. A radiative transfer modeling of the circumstellar structure, based on the quiescent spectral energy distribution, indicates a disk with a mass of $4{\times}10^{-3}\,M_{\odot}$. Our simple accretion disk modeling implies that the accretion rate had been exponentially increasing for more than 3 years until mid-2019, when it reached a peak value of $6.9 \times 10^{-6}\,M_{\odot}$yr$^{-1}$. In many respects, Gaia18dvy is similar to the FU Ori-type object HBC 722
- [17] arXiv:2005.11562 [pdf, other]
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Title: The Mass Accretion Rate of Clusters of Galaxies: CIRS and HeCSAuthors: M. Pizzardo, S. Di Gioia, A. Diaferio, C. De Boni, A. L. Serra, M. J. Geller, J. Sohn, K. Rines, M. BaldiComments: 24 pages, 18 figures, 7 tablesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We use a new spherical accretion recipe tested on N-body simulations to measure the observed mass accretion rate (MAR) of 129 clusters in the CIRS and HeCS. The observed clusters cover the redshift range $0.01 < z < 0.30$ and the mass range $\sim 10^{14}-10^{15}h^{-1}\text{M}_\odot$. Based on three-dimensional mass profiles of simulated clusters reaching beyond the virial radius, our recipe returns MARs that agree with MARs based on merger trees. We adopt this recipe to estimate the MAR of real clusters based on measurement of the mass profile out to $\sim 3R_{200}$. We use the caustic method to measure the mass profiles to these large radii. We demonstrate the solidity of our estimates by applying the same approach to a set of mock redshift surveys of a sample of 2000 simulated clusters with median mass $M_{200}= 10^{14} {\,h^{-1}\rm{M_{\odot}}}$, and a sample of 50 simulated clusters with median mass $M_{200}= 10^{15} {\,h^{-1}\rm{M_{\odot}}}$: the median MARs based on the caustic mass profiles of the simulated clusters are unbiased and agree within $17\%$ with the median MARs based on the real mass profile of the clusters. The MAR of the CIRS and HeCS clusters increases with the mass and the redshift of the accreting cluster, in excellent agreement with the growth of clusters in the $\Lambda$CDM model.
- [18] arXiv:2005.11565 [pdf]
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Title: Retrieval of Particle Size Distribution of Polar Stratospheric Clouds Based on Wide-Angle Color and Polarization AnalysisComments: 15 pages, 11 figures, submitted to Planetary and Space ScienceSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Atmospheric and Oceanic Physics (physics.ao-ph)
The intensive polar stratospheric vortex in the Arctic that shifted to northern Europe in the winter of 2019-2020 caused low temperatures and the frequent occurrence of polar stratospheric clouds followed by a significant decrease in the total ozone content. Polarimetry and multi-color photometry using all-sky cameras in Lovozero (Murmansk Region, Russia, 68.0 deg N, 35.1 deg E) together with a new method of cloud field separation against the twilight background allowed for finding the light scattering characteristics related to the particle size distribution of polar stratospheric clouds. The results are compared with lidar and balloon experiments. The conditions of the appearance of visually bright polar stratospheric clouds of type I are discussed.
- [19] arXiv:2005.11566 [pdf, other]
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Title: On the Metamorphosis of the Bailey diagram for RR Lyrae starsAuthors: G. Bono, V. F. Braga, J. Crestani, M. Fabrizio, C. Sneden, M. Marconi, G. W. Preston, J. P. Mullen, C. K. Gilligan, G. Fiorentino, A. Pietrinferni, G. Altavilla, R. Buonanno, B. Chaboyer, R. da Silva, M. Dall'Ora, S. Degl'Innocenti, E. Di Carlo, I. Ferraro, E. Grebel, G. Iannicola, L. Inno, V. Kovtyukh, A. Kunder, B. Lemasle, M. Marengo, S. Marinoni, P. M. Marrese, C. E. Martínez-Vázquez, N. Matsunaga, M. Monelli, J. Neeley, M. Nonino, P.G. Prada Moroni, Z. Prudil, P. B. Stetson, F. Thévenin, E. Tognelli, E. Valenti, A. R. WalkerComments: 14 pages, 4 figures, 1 table, Accepted on ApJ LetterSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
We collected over 6000 high-resolution spectra of four dozen field RR Lyrae (RRL) variables pulsating either in the fundamental (39 RRab) or in the first overtone (9 RRc) mode. We measured radial velocities (RVs) of four strong metallic and four Balmer lines along the entire pulsational cycle and derived RV amplitudes with accuracies better than 1$-$2~\kmsec. The new amplitudes were combined with literature data for 23~RRab and 3~RRc stars (total sample 74 RRLs) which allowed us to investigate the variation of the Bailey diagram (photometric amplitude versus period) when moving from optical to mid-infrared bands and to re-cast the Bailey diagram in terms of RV amplitudes. We found that RV amplitudes for RRab are minimally affected by nonlinear phenomena (shocks) and multi-periodicity (Blazhko effect). The RV slope ($\log P$--A(V$_r$)) when compared with the visual slope ($\log P$--A($V$)) is shallower and the dispersion, at fixed period, decreases by a factor of two. We constructed homogeneous sets of Horizontal Branch evolutionary models and nonlinear, convective pulsation models of RRLs to constrain the impact of evolutionary effects on their pulsation properties. Evolution causes, on the Bailey diagram based on RV amplitudes, a modest variation in pulsation period and a large dispersion in amplitude. The broad dispersion in period of the Bailey diagram is mainly caused by variation in RRL intrinsic parameters (stellar mass, chemical composition). Empirical evidence indicates that RV amplitudes are an optimal diagnostic for tracing the mean effective temperature across the RRab instability strip.
- [20] arXiv:2005.11573 [pdf]
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Title: Nuclear obscuration structure in Mrk 417 based on NuSTAR and Swift/BAT dataComments: 18 pages, 4 figures, 2 tables, accepted for publication to Astrofizika (Astrophysics (Ap)), main text in Russian but with a large detailed description at EnglishSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We present the results of X-ray spectral analysis of the Seyfert type 2 galaxy Mrk 417 observed by the NuSTAR (3-60 keV) and the Swift/BAT (14-150) observatories. The NuSTAR data shows a good fit with a baseline model which composed of an absorbed cutoff power-law component and reflected emission from the cold neutral medium. We found that the spectrum is steep $\Gamma = 1.63_{-0.11}^{+0.10}$ and obscured by hydrogen column density of $N_{H} = 3.22_{-0.39}^{+0.41} \cdot 10^{23} cm^{-2}$, narrow $FeK_\alpha$ emission line has an equivalent width of $EW = 115_{-1}^{+2}$ eV that suggests this feature is originated in a moderate density of obscurer. In combining NuSTAR data with Swift/BAT spectrum we also applied a more physically motivated approach using complex physical models MYTorus and BNTorus. For the first case the photon index of $\Gamma_{MYTorus} = 1.68_{-0.09}^{+0.09}$ and the line-of-sight column density of the absorber $N_{H,l.o.s} = 3.36_{-0.07}^{+0.04} \cdot 10^{23} cm^{-2}$. Applying BNTorus model shows the photon index $\Gamma_{BNTorus} = 1.75_{-0.09}^{+0.09}$ and absorption $N_{H,l.o.s} = 3.72_{-0.39}^{+0.49} \cdot 10^{23} cm^{-2}$. Based on the results we get an estimation of gas-dust torus covering factor $f_{c} = 0.29-0.34$ and an intrinsic X-ray luminosity in 2-10 keV of $\approx 3.16\cdot 10^{43}$ erg/s. Further analysis of Mid-Infrared (MIR) observational data, indicates that the covering factor maybe even smaller $f_{c} \approx 0.12$. Our results allow us to suggest that obscuring material of Mrk 417 has preferably a ring-like geometry.
- [21] arXiv:2005.11581 [pdf, other]
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Title: Gamma-ray counterparts of 2WHSP high-synchrotron-peaked BL Lac objects as possible signatures of ultra-high-energy cosmic-ray emissionComments: 15 pages, 9 figures, 2 tables, submitted to MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We present a search for high-energy $\gamma$-ray emission from 566 Active Galactic Nuclei at redshift $z > 0.2$, from the 2WHSP catalog of high-synchrotron peaked BL Lac objects with eight years of Fermi-LAT data. We focus on a redshift range where electromagnetic cascade emission induced by ultra-high-energy cosmic rays can be distinguished from leptonic emission based on the spectral properties of the sources. Our analysis leads to the detection of 160 sources above $\approx$ $5\sigma$ (TS $\geq 25$) in the 1 - 300 GeV energy range. By discriminating significant sources based on their $\gamma$-ray fluxes, variability properties, and photon index in the Fermi-LAT energy range, and modeling the expected hadronic signal in the TeV regime, we select a list of promising sources as potential candidate ultra-high-energy cosmic-ray emitters for follow-up observations by Imaging Atmospheric Cherenkov Telescopes.
- [22] arXiv:2005.11587 [pdf, other]
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Title: The Space Environment and Atmospheric Joule Heating of the Habitable Zone Exoplanet TOI700-dComments: accepted to ApJSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Space Physics (physics.space-ph)
We investigate the space environment conditions near the Earth-size planet TOI~700~d using a set of numerical models for the stellar corona and wind, the planetary magnetosphere, and the planetary ionosphere. We drive our simulations using a scaled-down stellar input and a scaled-up solar input in order to obtain two independent solutions. We find that for the particular parameters used in our study, the stellar wind conditions near the planet are not very extreme -- slightly stronger than that near the Earth in terms of the stellar wind ram pressure and the intensity of the interplanetary magnetic field. Thus, the space environment near TOI700-d may not be extremely harmful to the planetary atmosphere, assuming the planet resembles the Earth. Nevertheless, we stress that the stellar input parameters and the actual planetary parameters are unconstrained, and different parameters may result in a much greater effect on the atmosphere of TOI700-d. Finally, we compare our results to solar wind measurements in the solar system and stress that modest stellar wind conditions may not guarantee atmospheric retention of exoplanets.
- [23] arXiv:2005.11598 [pdf, other]
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Title: The cosmic web connection to the dark matter halo distribution through gravityAuthors: Francisco-Shu Kitaura, Andrés Balaguera-Antolínez, Francesco Sinigaglia, Marcos Pellejero-IbáñezComments: 5 pages, 3. figures and supplemental material with 11 page, 4 figuresand 2 tablesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Classical Physics (physics.class-ph); Computational Physics (physics.comp-ph)
In this letter we investigate the connection between the cosmic web and the halo distribution through the gravitational potential. We combine three fields of research, cosmic web classification, perturbation theory expansions of the halo bias, and halo (galaxy) mock catalog making methods. In particular, we use the invariants of the tidal field tensor as generating functions (dubbed I-web), to reproduce the halo number counts of a reference catalog from full gravity calculations, populating the dark matter field on a mesh well into the non-linear regime ($\sim5$ Mpc scales). Our results show an unprecedented agreement with the reference power spectrum within 0.5% up to $k=0.72\,h$ Mpc$^{-1}$. By analysing the three point statistics on large scales (configurations of up to $k=0.2\,h$ Mpc$^{-1}$), we find evidence for non-local bias at the 4.8 $\sigma$ confidence level (an information gain of $\sim$ 3.4 $\sigma$ over the commonly used T-web), being fully compatible with the reference catalog. In particular, we find that a detailed description of tidal anisotropic clustering on large scales is crucial to achieve this accuracy. We conclude that the I-web can potentially be useful to study the cosmic web, to improve the generation of mock galaxy catalogs, to improve on halo mass reconstructions, to study primordial non-Gaussianities, to develop new effective Eulerian galaxy bias models at the field level, and to investigate galaxy evolution improving on environmental studies.
- [24] arXiv:2005.11606 [pdf, other]
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Title: New Gamma-Ray Bursts Found in the Archival Data from the IBIS/ISGRI Telescope of the INTEGRAL ObservatoryAuthors: I. V. Chelovekov, S. A. Grebenev, A. S. Pozanenko, P. Yu. Minaev (Space Research Institute, Russian Academy of Sciences)Comments: 19 pages, 12 figures, 4 tablesJournal-ref: Astronomy Letters, 45 (2019), 635-654Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
A systematic search for cosmic gamma-ray bursts (GRBs) and other short hard X-ray events in the archival data from the IBIS/ISGRI telescope of the INTEGRAL observatory over 2003-2018 has been carried out. Seven previously unknown GRBs have been recorded in the telescope field of view; all of them have been localized with an accuracy < 2 arcmin. These events were not revealed by the INTEGRAL burst alert system (IBAS) designed for an automatic GRB search and alert. Four more such localized events missed by IBAS, but known previously, i.e., observed in other experiments, have been found. Eight hundred and eighty six GRBs outside the field of view that arrived at large angles to the IBIS/ISGRI axis have also been recorded. All of them were previously recorded in other experiments, primarily by the anticoincidence shield (ACS) of the SPI gamma-ray spectrometer onboard INTEGRAL, the PICsIT detector of the IBIS gamma-ray telescope, and the KONUS/WIND monitor. An order of magnitude more events without any confirmations in other experiments have been recorded. Both GRBs and solar flares or magnetospheric transient events can be among them. Catalogs with the basic parameters of confirmed and previously unknown GRBs recorded by IBIS/ISGRI have been compiled. The statistical distributions of bursts in various parameters have been constructed and investigated.
- [25] arXiv:2005.11678 [pdf, ps, other]
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Title: A method for classification of red, blue and green galaxies using fuzzy set theoryAuthors: Biswajit PandeyComments: 5 pages, 2 figures, Comments are welcomeSubjects: Astrophysics of Galaxies (astro-ph.GA)
Red and blue galaxies are traditionally classified using some specific cuts in colour or other galaxy properties. These cuts remain largely arbitrary supported only by empirical arguments. Galaxy colours show a gradual transition and the vagueness associated with such cuts are likely to introduce a significant contamination in these samples. Fuzzy set theory provides a natural framework to capture the classification uncertainty in the absence of any precise boundary. We propose a method for classification of galaxies according to their colours using fuzzy set theory.
- [26] arXiv:2005.11709 [pdf, other]
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Title: PHANGS CO kinematics: disk orientations and rotation curves at 150 pc resolutionAuthors: Philipp Lang, Sharon E. Meidt, Erik Rosolowsky, Joseph Nofech, Eva Schinnerer, Adam K. Leroy, Eric Emsellem, Ismael Pessa, Simon C. O. Glover, Brent Groves, Annie Hughes, J. M. Diederik Kruijssen, Miguel Querejeta, Andreas Schruba, Frank Bigiel, Guillermo A. Blanc, Melanie Chevance, Dario Colombo, Christopher Faesi, Jonathan D. Henshaw, Cinthya N. Herrera, Daizhong Liu, Jerome Pety, Johannes Puschnig, Toshiki Saito, Jiayi Sun, Antonio UseroComments: 19 figures, 36 pages, accepted for publication in ApJ. Table of PHANGS rotation curves available from this http URLSubjects: Astrophysics of Galaxies (astro-ph.GA)
We present kinematic orientations and high resolution (150 pc) rotation curves for 67 main sequence star-forming galaxies surveyed in CO (2-1) emission by PHANGS-ALMA. Our measurements are based on the application of a new fitting method tailored to CO velocity fields. Our approach identifies an optimal global orientation as a way to reduce the impact of non-axisymmetric (bar and spiral) features and the uneven spatial sampling characteristic of CO emission in the inner regions of nearby galaxies. The method performs especially well when applied to the large number of independent lines-of-sight contained in the PHANGS CO velocity fields mapped at 1'' resolution. The high resolution rotation curves fitted to these data are sensitive probes of mass distribution in the inner regions of these galaxies. We use the inner slope as well as the amplitude of our fitted rotation curves to demonstrate that CO is a reliable global dynamical mass tracer. From the consistency between photometric orientations from the literature and kinematic orientations determined with our method, we infer that the shapes of stellar disks in the mass range of log($\rm M_{\star}(M_{\odot})$)=9.0-10.9 probed by our sample are very close to circular and have uniform thickness.
- [27] arXiv:2005.11712 [pdf, ps, other]
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Title: A beamforming approach to the self-calibration of phased arraysSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Signal Processing (eess.SP)
In this paper, we propose a beamforming method for the calibration of the direction-independent gain of the analog chains of aperture arrays. The gain estimates are obtained by cross-correlating the output voltage of each antenna with a voltage beamformed using the other antennas of the array. When the beamforming weights are equal to the average cross-correlated power, a relation is drawn with the StEFCal algorithm. An example illustrates this approach for few point sources and a 256-element array.
- [28] arXiv:2005.11713 [pdf, other]
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Title: A new correction method for quasi-Keplerian orbitsComments: 16 pages, 48 figuresSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Computational Physics (physics.comp-ph)
A pure two-body problem has seven integrals including the Kepler energy, the Laplace vector, and the angular momentum vector. However, only five of them are independent. When the five independent integrals are preserved, the two other dependent integrals are naturally preserved from a theoretical viewpoint; but they may not be either from a numerical computational viewpoint. Because of this, we use seven scale factors to adjust the integrated positions and velocities so that the adjusted solutions strictly satisfy the seven constraints. Noticing the existence of the two dependent integrals, we adopt the Newton iterative method combined with the singular value decomposition to calculate these factors. This correction scheme can be applied to perturbed two-body and N-body problems in the solar system. In this case, the seven quantities of each planet slowly vary with time. More accurate values can be given to the seven slowly-varying quantities by integrating the integral invariant relations of these quantities and the equations of motion. They should be satisfied with the adjusted solutions. Numerical tests show that the new method can significantly reduce the rapid growth of numerical errors of all orbital elements.
- [29] arXiv:2005.11725 [pdf, other]
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Title: Strong H-alpha emission and signs of accretion in a circumbinary planetary mass companion from MUSEAuthors: Simon Eriksson, Rubén Asensio Torres, Markus Janson, Yuhiko Aoyama, Gabriel-Dominique Marleau, Mickael Bonnefoy, Simon PetrusComments: Accepted for publication in A&A. 11 pages. Supplementary material and figures in appendixSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR)
Context: Using intrinsic H-alpha emission to detect substellar companions can be advantageous for improving contrasts in direct imaging, and probing planetary formation theories through the characterisation of accreting exoplanets. Aims: In this work we aim to characterise the young circumbinary planetary mass companion 2MASS J01033563-5515561 (AB)b (Delorme 1 (AB)b) through medium resolution spectroscopy. Methods: We have used the new Narrow-Field Mode (NFM) for the MUSE integral-field spectrograph, located on the ESO Very Large Telescope, during SV time to obtain optical spectra of Delorme 1 (AB)b. Results: We report the discovery of very strong H-alpha and H-beta emission, accompanied by He I emission, consistent with an active accretion scenario. We provide accretion rate estimates obtained from several independent methods and find a likely mass of 12-15 M_Jup for Delorme 1 (AB)b, also consistent with previous estimates. Conclusions: Signs of active accretion in the Delorme 1 system could indicate a younger age than the ~30-40 Myr expected from a likely Tucana-Horologium (THA) membership. Previous works have also shown the central binary to be overluminous, which gives further indication of a younger age. However, recent discoveries of active disks in relatively old (~40 Myr), very low-mass systems suggests that ongoing accretion in Delorme 1 (AB)b might not require in and of itself that the system is younger than the age implied by its THA membership.
- [30] arXiv:2005.11798 [pdf, other]
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Title: The distribution of dark galaxies and spin biasSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
In the light of the discovery of numerous (almost) dark galaxies from the ALFALAFA and LITTLE THINGS surveys, we revisit the predictions of Jimenez et al. 1997, based on the Toomre stability of rapidly-spinning gas disks. We have updated the predictions for $\Lambda$CDM with parameters given by Planck18, computing the expected number densities of dark objects, and their spin parameter and mass distributions. Comparing with the data is more challenging, but where the spins are more reliably determined, the spins are close to the threshold for disks to be stable according to the Toomre criterion, where the expected number density is highest, and reinforces the concept that there is a bias in the formation of luminous galaxies based on the spin of their parent halo.
- [31] arXiv:2005.11819 [pdf, other]
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Title: Galaxy cluster mass estimation with deep learning and hydrodynamical simulationsComments: 13 pages, 11 figures, 2 tablesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We evaluate the ability of Convolutional Neural Networks (CNNs) to predict galaxy cluster masses in the BAHAMAS hydrodynamical simulations. We train four separate single-channel networks using: stellar mass, soft X-ray flux, bolometric X-ray flux, and the Compton $y$ parameter as observational tracers, respectively. Our training set consists of $\sim$6400 synthetic cluster images generated from the simulation, while an additional $\sim$1600 images form a test set. We also train a `multi-channel' CNN by combining the four observational tracers. We utilize $\texttt{Keras}$ with a $\texttt{Tensorflow}$ backend to train the network, and all four converge within 2000 epochs. The cluster masses predicted from these networks are evaluated using the average fractional difference between predicted cluster mass and true cluster mass. The resulting predictions are especially precise for halo masses in the range $10^{13.25}M_{\odot}<M<10^{14.5}M_{\odot}$, where all five networks produce mean mass biases of order $\approx 1\%$ with a scatter on the mean bias of $\approx 0.5\%$. The network trained with Compton $y$ parameter maps yields the most precise predictions. We interpret the network's behaviour using two diagnostic tests to determine which features are used to predict cluster mass. The CNN trained with stellar mass images detect galaxies (not surprisingly), while CNNs trained with gas-based tracers utilise the shape of the signal to estimate cluster mass.
- [32] arXiv:2005.11829 [pdf]
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Title: Multi-wavelength Study of Energetic Processes during Solar Flares occurrenceComments: pages 18, 13 figures, accepted in RAA 2020Journal-ref: Research in astronomy and Astrophysics 2020Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
This paper is an attempt to understand the physical processes occurring in different layers of solar atmosphere during a solar flare. For a complete understanding of the flare we must analyze multi-wavelength datasets, as emission at different wavelength originates from different layers of the solar atmosphere. Also, flares are transient and localized events observed to occur at all longitudes. With these considerations, we have carried out multi-wavelength analysis of two representative flare events. One event occurred close to the centre of the solar disk and other occurred close to the limb. In the former case, we examine the emission from the lower layers of the solar atmosphere. Therefore the chromospheres, transition region and also the photospheric magneto-gram can be analyzed. On the other hand, in near-limb event, coronal features can be clearly studied. In this paper, the first event studied is the M 1.1 class flare from the active region NOAA 10649 located at S10E14 and the second event is the M 1.4 class flare from the active region NOAA 10713 located at S12W90. In both cases, we have observed the excellent multi-wavelength data sets. The observations from multi-instrumental data clearly shows that flares occur in the vicinity of sunspots. These are regions of strong magnetic field with mixed polarity.
- [33] arXiv:2005.11880 [pdf, other]
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Title: A giant galaxy in the young Universe with a massive ringAuthors: Tiantian Yuan, Ahmed Elagali, Ivo Labbe, Glenn G. Kacprzak, Claudia del P. Lagos, Leo Y. Alcorn, Jonathan H. Cohn, Kim-Vy H. Tran, Karl Glazebrook, Brent A. Groves, Kenneth C. Freeman, Lee R. Spitler, Caroline M. S. Straatman, Deanne B. Fisher, Sarah M. SweetComments: Author's version for the main article (10 pages). The Supplementary Information (22 pages) and a combined pdf are provided here this http URL Published version available online this http URLJournal-ref: Nature Astronomy 2020Subjects: Astrophysics of Galaxies (astro-ph.GA)
In the local (redshift z~0) Universe, collisional ring galaxies make up only ~0.01% of galaxies and are formed by head-on galactic collisions that trigger radially propagating density waves. These striking systems provide key snapshots for dissecting galactic disks and are studied extensively in the local Universe. However, not much is known about distant (z>0.1) collisional rings. Here we present a detailed study of a ring galaxy at a look-back time of 10.8 Gyr (z=2.19). Compared with our Milky Way, this galaxy has a similar stellar mass, but has a stellar half-light radius that is 1.5-2.2 times larger and is forming stars 50 times faster. The large, diffuse stellar light outside the star-forming ring, combined with a radial velocity on the ring and an intruder galaxy nearby, provides evidence for this galaxy hosting a collisional ring. If the ring is secularly evolved, the implied large bar in a giant disk would be inconsistent with the current understanding of the earliest formation of barred spirals. Contrary to previous predictions, this work suggests that massive collisional rings were as rare 11 Gyr ago as they are today. Our discovery offers a unique pathway for studying density waves in young galaxies, as well as constraining the cosmic evolution of spiral disks and galaxy groups.
- [34] arXiv:2005.11881 [pdf, ps, other]
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Title: Population Synthesis of Massive Close Binary EvolutionAuthors: J.J. EldridgeComments: Author version of a chapter for the 'Handbook of Supernovae', edited by A. Alsabti and P. Murdin, Springer. 22 pages, 4 figures, 1 tableJournal-ref: Handbook of Supernovae, ISBN 978-3-319-21845-8. Springer International Publishing AG, 2017, p. 671Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Binary population synthesis is the method by which predictions of varied observables of stellar populations can be made from theoretical models of binary stellar evolution. Binary stars have many more possible evolutionary outcomes compared to single stars and the relative rates of the different pathways, such as the rates of different supernova types, depend on uncertain or poorly constrained physics. In this Chapter we describe population synthesis, outline the major uncertainties and discuss the relevant predictions for core-collapse supernovae. After we overview single star evolution we outline the important physical processes that occur in binaries including Roche-lobe overflow, common-envelope evolution and supernova kicks. We also discuss how a synthetic stellar population incorporating interacting binaries can be constructed and how uncertainties, such as the strength of supernova kicks, affect any predictions. We illustrate the process by comparing predictions for the stellar populations in two young star clusters. We then discuss the important predictions from population synthesis for understanding core-collapse supernovae, their delay-time distribution and their progenitor stars. Finally we discuss how we can predict the rate of mergers of compact remnants and thus predict the initial parameters of gravitational wave sources.
- [35] arXiv:2005.11883 [pdf, ps, other]
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Title: Population and spectral synthesis: it doesn't work without binariesComments: Authors' copy of manuscript that appears in, The Impact of Binaries on Stellar Evolution, Beccari G. & Boffin H.M.J. (Eds.). Copyright, 2018 Cambridge University Press. Full text to be found here: this https URL ). 24 pages, 4 figuesJournal-ref: Population and Spectral Synthesis: It Doesn't Work without Binaries. (2019). In G. Beccari & H. Boffin (Eds.), The Impact of Binary Stars on Stellar Evolution (Cambridge Astrophysics, pp. 307-328). Cambridge: Cambridge University PressSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
In this chapter we discuss the population and spectral synthesis of stellar populations. We describe the method required to achieve such synthesis and discuss examples where inclusion of interacting binaries are vital to reproducing the properties of observed stellar systems. These examples include the Hertzsprung-Russel diagram, massive star number counts, core-collapse supernovae and the ionising radiation from stellar populations that power both nearby HII regions and the epoch of reionization. We finally offer some speculations on the future paths of research in spectral synthesis.
- [36] arXiv:2005.11889 [pdf, other]
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Title: Degenerate dark matter micro-nuggets from $\rm{eV}$ sterile states and the Hubble tensionSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
We present a novel scenario in which light decoupled fermions with mass $\sim$ few eV, such as like light sterile neutrinos, undergo a phase transition during the radiation dominated epoch driven by a scalar-mediated force and become trapped in nuggets of degenerate matter that are stable over cosmological timescales. These heavy dark nuggets behave like cold dark matter. The stability of the dark matter nugget is achieved when the Fermi pressure balances the attractive scalar force (akin to white dwarfs or neutron stars) and we numerically solve to identify the static configuration. We also highlight that prior to nugget formation, the semi-relativistic sterile states can annihilate to scalar radiation, thus increasing the Hubble expansion rate prior to the Cosmic Microwave Background epoch and alleviating the Hubble tension. We also show that once the dark nugget forms, the annihilation into scalar radiation becomes subdominant, and the nugget lifetime can be easily greater than the age of the universe.
- [37] arXiv:2005.11917 [pdf, other]
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Title: Galaxy And Mass Assembly (GAMA): A forensic SED reconstruction of the cosmic star-formation history and metallicity evolution by galaxy typeAuthors: Sabine Bellstedt, Aaron S. G. Robotham, Simon P. Driver, Jessica E. Thorne, Luke J. M. Davies, Claudia del P. Lagos, Adam R. H. Stevens, Edward N. Taylor, Ivan K. Baldry, Amanda J. Moffett, Andrew M. Hopkins, Steven PhillippsComments: 21 pages, 15 figures, submitted to MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
We apply the spectral energy distribution-fitting code ProSpect to multiwavelength imaging for $\sim$7,000 galaxies from the GAMA survey at $z<0.06$, in order to extract their star-formation histories. We combine a parametric description of the star formation history with a closed-box evolution of metallicity where the present-day gas-phase metallicity of the galaxy is a free parameter. We show with this approach that we are able to recover the observationally-determined cosmic star formation history (CSFH), an indication that stars are being formed in the correct epoch of the Universe, on average, for the manner in which we are conducting SED fitting.
We also show the contribution to the CSFH of galaxies of different present-day visual morphologies, and stellar masses. This analysis suggests that half of the mass in present-day elliptical galaxies was in place 11 Gyr ago, whereas in other morphological types the stellar mass formed later, up to 6 Gyr ago for present-day irregular galaxies. Similarly, the most massive galaxies in our sample were shown to have formed half their stellar mass by 10.5 Gyr ago, whereas the least massive galaxies formed half their stellar mass as late as 4 Gyr ago (the well-known effect of "galaxy downsizing"). Finally, our metallicity approach allows us to follow the average evolution in gas-phase metallicity for populations of galaxies, and extract the evolution of the cosmic metal mass density in stars and in gas, producing results in broad agreement with observations of metal densities in the Universe. - [38] arXiv:2005.11939 [pdf]
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Title: Aerosol Composition of Hot Giant Exoplanets Dominated by Silicates and Hydrocarbon HazesAuthors: Peter Gao, Daniel P. Thorngren, Graham K. H. Lee, Jonathan J. Fortney, Caroline V. Morley, Hannah R. Wakeford, Diana K. Powell, Kevin B. Stevenson, Xi ZhangComments: 32 pages, 4 main text figures, 7 supplementary figures, 4 supplementary tables, published in Nature AstronomySubjects: Earth and Planetary Astrophysics (astro-ph.EP)
Aerosols are common in the atmospheres of exoplanets across a wide swath of temperatures, masses, and ages. These aerosols strongly impact observations of transmitted, reflected, and emitted light from exoplanets, obfuscating our understanding of exoplanet thermal structure and composition. Knowing the dominant aerosol composition would facilitate interpretations of exoplanet observations and theoretical understanding of their atmospheres. A variety of compositions have been proposed, including metal oxides and sulphides, iron, chromium, sulphur, and hydrocarbons. However, the relative contributions of these species to exoplanet aerosol opacity is unknown. Here we show that the aerosol composition of giant exoplanets observed in transmission is dominated by silicates and hydrocarbons. By constraining an aerosol microphysics model with trends in giant exoplanet transmission spectra, we find that silicates dominate aerosol opacity above planetary equilibrium temperatures of 950 K due to low nucleation energy barriers and high elemental abundances, while hydrocarbon aerosols dominate below 950 K due to an increase in methane abundance. Our results are robust to variations in planet gravity and atmospheric metallicity within the range of most giant transiting exoplanets. We predict that spectral signatures of condensed silicates in the mid-infrared are most prominent for hot (>1600 K), low-gravity (<10 m s$^{-2}$) objects.
- [39] arXiv:2005.11954 [pdf, other]
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Title: Orbital and mass constraints of the young binary system IRAS 16293-2422 AAuthors: Maria Jose Maureira, Jaime E. Pineda, Dominique M. Segura-Cox, Paola Caselli, Leonardo Testi, Giuseppe Lodato, Laurent Loinard, Antonio Hernandez-GomezComments: Accepted for publication in ApJ. 23 pages, 14 figures, 4 tablesSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
We present 3 mm ALMA continuum and line observations at resolutions of 6.5 au and 13 au respectively, toward the Class 0 system IRAS 16293-2422 A. The continuum observations reveal two compact sources towards IRAS 16293-2422 A, coinciding with compact ionized gas emission previously observed at radio wavelengths (A1 and A2), confirming the long-known radio sources as protostellar. The emission towards A2 is resolved and traces a dust disk with a FWHM size of $\sim$12 au, while the emission towards A1 sets a limit to the FWHM size of the dust disk of $\sim$4 au. We also detect spatially resolved molecular kinematic tracers near the protostellar disks. Several lines of the $J=5-4$ rotational transition of HNCO, NH$_2$CHO and t-HCOOH are detected, with which we derived individual line-of-sight velocities. Using these together with the CS ($J=2-1$), we fit Keplerian profiles towards the individual compact sources and derive masses of the central protostars. The kinematic analysis indicates that A1 and A2 are a bound binary system. Using this new context for the previous 30 years of VLA observations, we fit orbital parameters to the relative motion between A1 and A2 and find the combined protostellar mass derived from the orbit is consistent with the masses derived from the gas kinematics. Both estimations indicate masses consistently higher ($0.5\lesssim M_1\lesssim M_2 \lesssim2$ M$_{\odot}$) than previous estimations using lower resolution observations of the gas kinematics. The ALMA high-resolution data provides a unique insight into the gas kinematics and masses of a young deeply embedded bound binary system.
- [40] arXiv:2005.11959 [pdf, other]
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Title: Cold molecular gas and PAH emission in Seyfert galaxiesAuthors: A. Alonso-Herrero, M. Pereira-Santaella, D. Rigopoulou, I. Garcia-Bernete, S. Garcia-Burillo, A. J. Dominguez-Fernandez, F. Combes, R. I. Davies, T. Diaz-Santos, D. Esparza-Arredondo, O. Gonzalez-Martin, A. Hernan-Caballero, E. K. S. Hicks, S. F. Hoenig, N. A. Levenson, C. Ramos Almeida, P. F. Roche, D. RosarioComments: Accepted for publication in A&ASubjects: Astrophysics of Galaxies (astro-ph.GA)
We investigate the relation between the detection of the $11.3\,\mu$m PAH feature in the nuclear ($\sim 24-230\,$pc) regions of 22 nearby Seyfert galaxies and the properties of the cold molecular gas. For the former we use ground-based (0.3-0.6" resolution) mid-infrared (mid-IR) spectroscopy. The cold molecular gas is traced by ALMA and NOEMA high (0.2-1.1") angular resolution observations of the CO(2-1) transition. Galaxies with a nuclear detection of the $11.3\,\mu$m PAH feature contain more cold molecular gas (median $1.6\times 10^7\,M_\odot$) and have higher column densities ($N({\rm H}_2) = 2 \times 10^{23}\,{\rm cm}^{-2}$) over the regions sampled by the mid-IR slits than those without a detection. This suggests that molecular gas plays a role in shielding the PAH molecules in the harsh environments of Seyfert nuclei. Choosing the PAH molecule naphthalene as an illustration, we compute its half-life in the nuclear regions of our sample when exposed to 2.5keV hard X-ray photons. We estimate shorter half-lives for naphthalene in nuclei without a $11.3\,\mu$m PAH detection than in those with a detection. The Spitzer/IRS PAH ratios on circumnuclear scales ($\sim$ 4" $\sim$ 0.25-1.3kpc) are in between model predictions for neutral and partly ionized PAHs. However, Seyfert galaxies in our sample with the highest nuclear H$_2$ column densities are not generally closer to the neutral PAH tracks. This is because in the majority of our sample galaxies, the CO(2-1) emission in the inner $\sim$ 4" is not centrally peaked and in some galaxies traces circumnuclear sites of strong star formation activity. Spatially resolved observations with the MIRI medium-resolution spectrograph (MRS) on the James Webb Space Telescope will be able to distinguish the effects of an active galactic nucleus (AGN) and star formation on the PAH emission in nearby AGN.
- [41] arXiv:2005.11962 [pdf, other]
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Title: Constraints on dark matter annihilation in $ω$ CentauriAuthors: Arpan Kar, Biswarup Mukhopadhyaya, Steven Tingay, Ben McKinley, Marijke Haverkorn, Sam McSweeney, Natasha Hurley-Walker, Sourav Mitra, Tirthankar Roy ChoudhuryComments: 7 pages, 4 figures, 1 tableSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
We present an analysis of Murchison Widefield Array radio telescope data from $\omega$ Cen, possibly a stripped dwarf spheroidal galaxy core captured by our Galaxy. Recent interpretations of Fermi-LAT $\gamma$-ray data by Brown {\it et al.} (2019) and Reynoso-Cordova {\it et al.} (2019) suggest that $\omega$ Cen may contain significant Dark Matter. We utilise their best-fit Dark Matter annihilation models, and an estimate of the magnetic field strength in $\omega$ Cen, to calculate the expected radio synchrotron signal from annihilation, and show that one can usefully rule out significant parts of the magnetic field - diffusion coefficient plane using the current observational limits. Improvement by a factor of 10-100 on these limits could constrain the models even more tightly.
- [42] arXiv:2005.11972 [pdf, other]
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Title: Magnetic fields from Multiplicative ChaosComments: 22 pages, 9 figures, Accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Solar and Stellar Astrophysics (astro-ph.SR); Fluid Dynamics (physics.flu-dyn); Plasma Physics (physics.plasm-ph)
An analytical model for fully developed three-dimensional incompressible turbulence was recently proposed in the hydrodynamics community, based on the concept of multiplicative chaos. It consists of a random field represented by means of a stochastic integral, which, with only a few parameters, shares many properties with experimental and numerical turbulence, including in particular energy transfer through scales (the cascade) and intermittency (non-Gaussianity) which is most conveniently controlled with a single parameter. Here, we propose three models extending this approach to MHD turbulence. Our formulae provide physically motivated 3D models of a turbulent velocity field and magnetic field coupled together. Besides its theoretical value, this work is meant to provide a tool for observers: a dozen of physically meaningful free parameters enter the description, which is useful to characterize astrophysical data.
- [43] arXiv:2005.11974 [pdf, other]
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Title: Gas and dust dynamics in starlight-heated protoplanetary disksAuthors: Mario Flock, Neal J. Turner, Richard P. Nelson, Wladimir Lyra, Natascha Manger, Hubert KlahrComments: ApJ acceptedSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Theoretical models of the ionization state in protoplanetary disks suggest the existence of large areas with low ionization and weak coupling between the gas and magnetic fields. In this regime hydrodynamical instabilities may become important. In this work we investigate the gas and dust structure and dynamics for a typical T Tauri system under the influence of the vertical shear instability (VSI). We use global 3D radiation hydrodynamics simulations covering all $360^\circ$ of azimuth with embedded particles of 0.1 and 1mm size, evolved for 400 orbits. Stellar irradiation heating is included with opacities for 0.1- to 10-$\mu$m-sized dust. Saturated VSI turbulence produces a stress-to-pressure ratio of $\alpha \simeq 10^{-4}$. The value of $\alpha$ is lowest within 30~au of the star, where thermal relaxation is slower relative to the orbital period and approaches the rate below which VSI is cut off. The rise in $\alpha$ from 20 to 30~au causes a dip in the surface density near 35~au, leading to Rossby wave instability and the generation of a stationary, long-lived vortex spanning about 4~au in radius and 40~au in azimuth. Our results confirm previous findings that mm size grains are strongly vertically mixed by the VSI. The scale height aspect ratio for 1mm grains is determined to be 0.037, much higher than the value $H/r=0.007$ obtained from millimeter-wave observations of the HL~Tau system. The measured aspect ratio is better fit by non-ideal MHD models. In our VSI turbulence model, the mm grains drift radially inwards and many are trapped and concentrated inside the vortex. The turbulence induces a velocity dispersion of $\sim 12$~m/s for the mm grains, indicating that grain-grain collisions could lead to fragmentation.
- [44] arXiv:2005.11999 [pdf, other]
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Title: Role of spectral resolution for infrared asteroid compositional analysis using meteorite spectraComments: Accepted in MNRAS for publication on May 22nd, 2020; 7 pages, 3 figuresSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
In this work the potential mineral identification of meteorites is analysed for the mid-infrared range, to evaluate observational possibilities for future missions targeting small body surfaces. Three carbonaceous and three ordinary chondrite meteorites are examined by a diffuse reflection (DRIFT) instrument, and the presence of principal minerals is confirmed by a powder diffraction method as well. The possibilities and constraints of mineral identifications in the mid-infrared are simulated by artificially degrading the spectral resolution. Our research shows that for the definite identification of principal mineral bands, a spectral resolution $\leq 10$~cm$^{-1}$ ($\leq 0.15 \mu$m) is needed. At 20-100~cm$^{-1}$ (0.3 - 1.5~$\mu$m) resolution the identification of these minerals is uncertain, and with a resolution $>100$~cm$^{-1}$, it is almost impossible.
- [45] arXiv:2005.12014 [pdf, other]
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Title: Unexpected late-time temperature increase observed in two neutron star crust cooling sources -- XTE~J1701-462 and EXO~0748-676Comments: accepted for publication by A&A lettersSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Transient LMXBs that host neutron stars (NSs) provide excellent laboratories for probing the dense matter physics present in NS crusts. During accretion outbursts in LMXBs, exothermic reactions may heat the NS crust, disrupting the crust-core equilibrium. When the outburst ceases, the crust cools to restore thermal equilibrium with the core. Monitoring this evolution allows us to probe the dense matter physics in the crust. Properties of the deeper crustal layers can be probed at later times after the end of the outburst. We report on the unexpected late-time temperature evolution (>2000 days after the end of their outbursts) of two NSs in LMXBs, XTE J1701-462 and EXO 0748-676. Although both these sources exhibited very different outbursts (in terms of duration and the average accretion rate), they exhibit an unusually steep decay of ~7 eV in the observed effective temperature (occurring in a time span of ~700 days) around ~2000 days after the end of their outbursts. Furthermore, they both showed an even more unexpected rise of ~3 eV in temperature (over a time period of ~500-2000 days) after this steep decay. This rise was significant at the 2.4{\sigma} and 8.5{\sigma} level for XTE J1701-462 and EXO 0748-676, respectively. The physical explanation for such behaviour is unknown and cannot be straightforwardly be explained within the cooling hypothesis. In addition, this observed evolution cannot be well explained by low-level accretion either without invoking many assumptions. We investigate the potential pathways in the theoretical heating and cooling models that could reproduce this unusual behaviour, which so far has been observed in two crust-cooling sources. Such a temperature increase has not been observed in the other NS crust-cooling sources at similarly late times, although it cannot be excluded that this might be a result of the inadequate sampling obtained at such late times.
- [46] arXiv:2005.12018 [pdf, other]
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Title: Measuring the local dark matter density with LAMOST DR5 and Gaia DR2Comments: 19 pages, 15 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA)
We apply the vertical Jeans equation to the kinematics of Milky Way stars in the solar neighbourhood to measure the local dark matter density. More than 90,000 G- and K-type dwarf stars are selected from the cross-matched sample of LAMOST DR5 and Gaia DR2 for our analyses. The mass models applied consist of a single exponential stellar disc, a razor thin gas disc and a constant dark matter density. We first consider the simplified vertical Jeans equation which ignores the tilt term and assumes a flat rotation curve. Under a Gaussian prior on the total stellar surface density, the local dark matter density inferred from Markov Chain Monte Carlo simulations is $0.0133_{-0.0022}^{+0.0024}\ {\rm M}_{\odot}\,{\rm pc}^{-3}$. The local dark matter densities for subsamples in an azimuthal angle range of $-10^{\circ} < \phi < 5^{\circ}$ are consistent within their 1$\sigma$ errors. However, the northern and southern subsamples show a large discrepancy due to plateaux in the northern and southern vertical velocity dispersion profiles. These plateaux may be the cause of the different estimates of the dark matter density between the north and south. Taking the tilt term into account has little effect on the parameter estimations and does not explain the north and south asymmetry. Taking half of the difference of $\sigma_{z}$ profiles as unknown systematic errors, we then obtain consistent measurements for the northern and southern subsamples. We discuss the influence of the vertical data range, the scale height of the tracer population, the vertical distribution of stars and the sample size on the uncertainty of the determination of the local dark matter density.
- [47] arXiv:2005.12030 [pdf]
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Title: Activity of (6478) Gault during January 13 - March 28, 2019Authors: Oleksandra Ivanova, Yuri Skorov, Igor Luk'yanyk, Dušan Tomko, Marek Husárik, Jürgen Blum, Oleg Egorov, Olga VoziakovaComments: 30 pages, 3 table, 10 figuresJournal-ref: MNRAS 2020Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
We present the results of photometric observations of active asteroid (6478) Gault performed at heliocentric distances from 2.46 to 2.30 au and geocentric distances from 1.79 to 1.42 au between January 15 and March 28, 2019. Observations were carried out at the 2.5-m telescope of SAI MSU (CMO) on January 15, 2019 and at the 1.3-m and 0.61-m telescopes (SPb) on February 6 and March 28, 2019, respectively. The direct images of the asteroid were obtained with the broad-band B, V and R filters. Comet-like structures were detected at all observation dates. Colour maps were built and colour variations along the tail for the observation made on January 15, 2019 were analyzed. The $Af\rho$ was calculated for the R filter, The evaluated value varies from 47 to 32 cm for the period from January to the end of March, 2019. The rotational period of the body is estimated from the light curve by different methods and is about 1.79 hr. Possible mechanisms of triggering Gault's activity are discussed.
- [48] arXiv:2005.12039 [pdf, other]
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Title: Deblending galaxies with Variational Autoencoders: a joint multi-band, multi-instrument approachComments: Abstract abridged. Our code is publicly available on GitHub here: this https URLSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The apparent superposition of galaxies with other astrophysical objects along the line of sight, a problem known as blending, will be a major challenge for upcoming, ground-based, deep, photometric galaxy surveys, such as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). Blending contributes to the systematic error budget of weak lensing studies by perturbing object detection and affecting photometric and shape measurements. Existing deblenders suffer from the lack of flexible yet accurate models of galaxy morphologies and therefore rely on assumptions (analytic profiles, symmetry, sparsity in a profile basis) to isolate galaxies within a blended scene. In this paper, we propose instead to use generative models based on deep neural networks, namely variational autoencoders (VAE), to learn a probabilistic model directly from data. Specifically, we train a VAE on images of centred, isolated galaxies, which we reuse in a second VAE-like neural network in charge of deblending galaxies. We train our networks on simulated images created with the GalSim software, including all six LSST bandpass filters as well as the visible and near-infrared bands of the Euclid satellite, as our method naturally generalises to multiple bands and data from multiple instruments. We validate our model and quantify deblending performance by measuring reconstruction errors in galaxy shapes and magnitudes. We obtain median errors on ellipticities between $\pm{0.01}$ and on $r$-band magnitude between $\pm{0.05}$ in most cases and shear multiplicative biases close to $10^{-2}$ in the optimal configuration. Finally, we discuss future challenges about training on real data and obtain encouraging results when applying transfer learning.
- [49] arXiv:2005.12041 [pdf, other]
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Title: Constraints on neutrino mass in the scenario of vacuum energy interacting with cold dark matter after Planck 2018Comments: 13 pages, 7 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
In this work, we investigate the constraints on the total neutrino mass in the scenario of vacuum energy interacting with cold dark matter (abbreviated as I$\Lambda$CDM) by using the latest cosmological observations. We consider four typical interaction forms, i.e., $Q=\beta H \rho_{\rm de}$, $Q=\beta H \rho_{\rm c}$, $Q=\beta H_{0} \rho_{\rm de}$, and $Q=\beta H_{0} \rho_{\rm c}$, in the I$\Lambda$CDM scenario. To avoid the large-scale instability problem in interacting dark energy models, we employ the extended parameterized post-Friedmann method for interacting dark energy to calculate the perturbation evolution of dark energy in these models. The observational data used in this work include the cosmic microwave background (CMB) measurements from the Planck 2018 data release, the baryon acoustic oscillation (BAO) data, the type Ia supernovae (SN) observation (Pantheon compilation), and the 2019 local distance ladder measurement of the Hubble constant $H_{0}$ from the Hubble Space Telescope. We find that, compared with those in the $\Lambda$CDM+$\sum m_{\nu}$ model, the constrains on $\sum m_{\nu}$ are looser in the four I$\Lambda$CDM+$\sum m_{\nu}$ models. When considering the three mass hierarchies of neutrinos, the constraints on $\sum m_{\nu}$ are tightest in the degenerate hierarchy case and loosest in the inverted hierarchy case. In addition, in the four I$\Lambda$CDM+$\sum m_{\nu}$ models, the values of coupling parameter $\beta$ are larger using the CMB+BAO+SN+$H_{0}$ data combination than that using the CMB+BAO+SN data combination, and $\beta>0$ is favored at more than 1$\sigma$ level when using CMB+BAO+SN+$H_{0}$ data combination. The issue of the $H_{0}$ tension is also discussed in this paper. We find that, compared with the $\Lambda$CDM+$\sum m_{\nu}$ model, the $H_{0}$ tension can be alleviated in the I$\Lambda$CDM+$\sum m_{\nu}$ model to some extent.
- [50] arXiv:2005.12048 [pdf, ps, other]
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Title: A Magnetar-Asteroid Impact Model for FRB 200428 Associated with an X-ray Burst from SGR 1935+2154Authors: Z. G. Dai (NJU)Comments: 5 pages in emulateapj format, 2 figures, model parameters recaled following discovery papers arXiv:2005.10324, arXiv:2005.10828, arXiv:2005.11071, arXiv:2005.11178, and arXiv:2005.06335Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Very recently, an extremely bright fast radio burst (FRB) 200428 with two pulses was discovered to come from the direction of the Galactic magnetar SGR 1935+2154, and an X-ray burst (XRB) counterpart was detected simultaneously. These observations favor magnetar-based interior-driven models. In this Letter, we propose a different model for FRB 200428 associated with an XRB from SGR 1935+2164, in which a magnetar with high proper velocity encounters an asteroid of mass $\sim {\rm a\,\,few}\times10^{20}\,$g. This asteroid is possibly disrupted tidally into a great number of fragments at radius $\sim {\rm a\,\,few}\times 10^{10}\,$cm in the stellar gravitational field and then impeded around the Alfv$\acute{\rm e}$n radius by an ultra-strong magnetic field and meanwhile two largest iron-nickel fragments of mass $\sim 10^{17}\,$g produce two pulses of FRB 200428. The whole asteroid is eventually accreted onto the poles along the magnetic lines, heating the stellar surface instantaneously and generating an XRB. We show that this gravitationally-powered model can interpret all of the observed features self-consistently.
- [51] arXiv:2005.12080 [pdf, other]
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Title: ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- II. Compact objects in ACA observations and star formation scaling relationsAuthors: Tie Liu, Neal J. Evans, Kee-Tae Kim, Pail F. Goldsmith, Sheng-Yuan Liu, Qizhou Zhang, Kenichi Tatematsu, Ke Wang, Mika Juvela, Leonardo Bronfman, Maria. R. Cunningham, Guido Garay, Tomoya Hirota, Jeong-Eun Lee, Sung-Ju Kang, Di Li, Pak-Shing Li, Diego Mardones, Sheng-Li Qin, Isabelle Ristorcelli, Anandmayee Tej, L. Viktor Toth, Jing-Wen Wu, Yue-Fang Wu, Hee-weon Yi, Hyeong-Sik Yun, Hong-Li Liu, Ya-Ping Peng, Juan Li, Shang-Huo Li, Chang-Won Lee, Zhi-Qiang Shen, Tapas Baug, Jun-Zhi Wang, Yong Zhang, Namitha Issac, Feng-Yao Zhu, Qiu-Yi Luo, Xun-Chuan Liu, Feng-Wei Xu, Yu Wang, Chao Zhang, Zhiyuan Ren, Chao ZhangComments: accepted to be published on MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
We report studies of the relationships between the total bolometric luminosity ($L_{\rm bol}$ or $L_{\rm TIR}$) and the molecular line luminosities of $J=1-0$ transitions of H$^{13}$CN, H$^{13}$CO$^+$, HCN, and HCO$^+$ with data obtained from ACA observations in the "ATOMS" survey of 146 active Galactic star forming regions. The correlations between $L_{\rm bol}$ and molecular line luminosities $L'_{\rm mol}$ of the four transitions all appear to be approximately linear. Line emission of isotopologues shows as large scatters in $L_{\rm bol}$-$L'_{\rm mol}$ relations as their main line emission. The log($L_{\rm bol}$/$L'_{\rm mol}$) for different molecular line tracers have similar distributions. The $L_{\rm bol}$-to-$L'_{\rm mol}$ ratios do not change with galactocentric distances ($R_{\rm GC}$) and clump masses ($M_{\rm clump}$). The molecular line luminosity ratios (HCN-to-HCO$^+$, H$^{13}$CN-to-H$^{13}$CO$^+$, HCN-to-H$^{13}$CN and HCO$^+$-to-H$^{13}$CO$^+$) all appear constant against $L_{\rm bol}$, dust temperature ($T_{\rm d}$), $M_{\rm clump}$ and $R_{\rm GC}$. Our studies suggest that both the main lines and isotopologue lines are good tracers of the total masses of dense gas in Galactic molecular clumps. The large optical depths of main lines do not affect the interpretation of the slopes in star formation relations. We find that the mean star formation efficiency (SFE) of massive Galactic clumps in the "ATOMS" survey is reasonably consistent with other measures of the SFE for dense gas, even those using very different tracers or examining very different spatial scales.
- [52] arXiv:2005.12085 [pdf, other]
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Title: The Fornax Deep Survey with VST. X. The catalog of sources in the FDS area, with an example study for globular clusters and background galaxiesAuthors: Michele Cantiello, Aku Venhola, Aniello Grado, Maurizio Paolillo, Raffaele D'Abrusco, Gabriella Raimondo, Massimo Quintini, Michael Hilker, Steffen Mieske, Crescenzo Tortora, Marilena Spavone, Massimo Capaccioli, Enrica Iodice, Reynier Peletier, Jesus Falcon Barroso, Luca Limatola, Nicola Napolitano, Pietro Schipani, Glenn van de Ven, Fabrizio Gentile, Giovanni CovoneComments: 25 pages, 18 figures, A&A accepted, tables 3-6 available on lineSubjects: Astrophysics of Galaxies (astro-ph.GA)
This paper continues the series of the Fornax Deep Survey (FDS). Following the previous studies dedicated to extended Fornax cluster members, we present the catalogs of compact stellar systems in the Fornax cluster as well as extended background sources and point-like sources. We derive ugri photometry of ~1.7 million sources over the $\sim$21 sq. degree area of FDS centered on NGC1399. For a wider area, of $\sim$27 sq. degs extending in the direction of NGC1316, we provide gri data for ~3.1 million sources. To improve the morphological characterization of sources we generate multi-band image stacks by coadding the best seeing gri-band single exposures with a cut at FWHM<=0.9 arcsec. We use the multi-band stacks as detection frames. The identification of compact sources is obtained from a combination of photometric and morphometric selection criteria taking as reference the properties of sources with well-defined classification from the literature. We present a preliminary analysis of globular cluster (GC) distributions in the Fornax area. The study confirms and extends further previous results. We observe the inter-galactic population of GCs, a population of mainly blue GCs centered on NGC1399, extends over $\sim$0.9Mpc, with an ellipticity $\sim$0.65. Several sub-structures extend over $\sim$0.5Mpc along various directions. Two of these structures do not cross any bright galaxy; one of them appears to be connected to NGC1404, a bright galaxy close to the cluster core and particularly poor of GCs. Using the gri catalogs we analyze the GC distribution over the extended FDS area, and do not find any obvious GC sub-structure bridging the two brightest cluster galaxies, NGC1316 and NGC1399. Although NGC1316 is twice brighter of NGC1399 in optical bands we estimate a factor of 3-4 richer GC population around NGC1399 compared to NGC1316, out to galactocentric distances of 40 arcmin
- [53] arXiv:2005.12097 [pdf, other]
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Title: On-sky verification of Fast and Furious focal-plane wavefront sensing: Moving forward toward controlling the island effect at Subaru/SCExAOAuthors: Steven P. Bos, Sébastien Vievard, Michael J. Wilby, Frans Snik, Julien Lozi, Olivier Guyon, Barnaby R.M. Norris, Nemanja Jovanovic, Frantz Martinache, Jean-François Sauvage, Christoph U. KellerComments: Accepted for publication in A&A. Abstract shortened for arXivSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
High-contrast imaging (HCI) observations of exoplanets can be limited by the island effect (IE). On the current generation of telescopes, the IE becomes a severe problem when the ground wind speed is below a few meters per second. This is referred to as the low-wind effect (LWE). The LWE severely distorts the point spread function (PSF), significantly lowering the Strehl ratio and degrading the contrast. In this article, we aim to show that the focal-plane wavefront sensing (FPWFS) algorithm, Fast and Furious (F&F), can be used to measure and correct the IE/LWE. We deployed the algorithm on the SCExAO HCI instrument at the Subaru Telescope using the internal near-infrared camera in H-band. We tested F&F with the internal source, and it was deployed on-sky to test its performance with the full end-to-end system and atmospheric turbulence. The performance of the algorithm was evaluated by two metrics based on the PSF quality: 1) the Strehl ratio approximation ($SRA$), and 2) variance of the normalized first Airy ring ($VAR$). Random LWE phase screens with a peak-to-valley wavefront error between 0.4 $\mu$m and 2 $\mu$m were all corrected to a $SRA$ $>$90\% and an $VAR\lessapprox0.05$. Furthermore, the on-sky results show that F&F is able to improve the PSF quality during very challenging atmospheric conditions (1.3-1.4'' seeing at 500 nm). Closed-loop tests show that F&F is able to improve the $VAR$ from 0.27 to 0.03 and therefore significantly improve the symmetry of the PSF. Simultaneous observations of the PSF in the {optical} ($\lambda = $ 750 nm, $\Delta \lambda =$ 50 nm) show that during these tests we were correcting aberrations common to the optical and NIR paths within SCExAO. Going forward, the algorithm is suitable for incorporation into observing modes, which will enable PSFs of higher quality and stability during science observations.
- [54] arXiv:2005.12114 [pdf, other]
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Title: Revisiting Proxima with ESPRESSOAuthors: A. Suárez Mascareño, J. P. Faria, P. Figueira, C. Lovis, M. Damasso, J. I. González Hernández, R. Rebolo, S. Cristiano, F. Pepe, N. C. Santos, M. R. Zapatero Osorio, V. Adibekyan, S. Hojjatpanah, A. Sozzetti, F. Murgas, M. Abreo, M. Affolter, Y. Alibert, M. Aliverti, R. Allart, C. Allende Prieto, D. Alves, M. Amate, G. Avila, V. Baldini, T. Bandi, S. C. C. Barros, A. Bianco, W. Benz, F. Bouchy, C. Broeng, A. Cabral, G. Calderone, R. Cirami, J. Coelho, P. Conconi, I. Coretti, C. Cumani, G. Cupani, V. D'Odorico, S. Deiries, B. Delabre, P. Di Marcantonio, X. Dumusque, D. Ehrenreich, A. Fragoso, L. Genolet, M. Genoni, R. Génova Santos, I. Hughes, O. Iwert, K. Ferber, J. Knusdrtrup, M. Landoni, B. Lavie, J. Lillo-Box, J. Lizon, G. Lo Curto, C. Maire, A. Manescau, et al. (31 additional authors not shown)Comments: 25 pages, 26 figuresSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR)
We aim to confirm the presence of Proxima b using independent measurements obtained with the new ESPRESSO spectrograph, and refine the planetary parameters taking advantage of its improved precision. We analysed 63 spectroscopic ESPRESSO observations of Proxima taken during 2019. We obtained radial velocity measurements with a typical radial velocity photon noise of 26 cm/s. We ran a joint MCMC analysis on the time series of the radial velocity and full-width half maximum of the cross-correlation function to model the planetary and stellar signals present in the data, applying Gaussian process regression to deal with stellar activity. We confirm the presence of Proxima b independently in the ESPRESSO data. The ESPRESSO data on its own shows Proxima b at a period of 11.218 $\pm$ 0.029 days, with a minimum mass of 1.29 $\pm$ 0.13 Me. In the combined dataset we measure a period of 11.18427 $\pm$ 0.00070 days with a minimum mass of 1.173 $\pm$ 0.086 Me. We find no evidence of stellar activity as a potential cause for the 11.2 days signal. We find some evidence for the presence of a second short-period signal, at 5.15 days with a semi-amplitude of merely 40 cm/s. If caused by a planetary companion, it would correspond to a minimum mass of 0.29 $\pm$ 0.08 Me. We find that the FWHM of the CCF can be used as a proxy for the brightness changes and that its gradient with time can be used to successfully detrend the radial velocity data from part of the influence of stellar activity. The activity-induced radial velocity signal in the ESPRESSO data shows a trend in amplitude towards redder wavelengths. Velocities measured using the red end of the spectrograph are less affected by activity, suggesting that the stellar activity is spot-dominated. The data collected excludes the presence of extra companions with masses above 0.6 Me at periods shorter than 50 days.
- [55] arXiv:2005.12117 [pdf, other]
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Title: Extended X-ray emission from the classic nova DQ Her -- On the possible presence of a magnetized jetComments: 8 pages, 4 figures, 1 table; accepted to MNRASSubjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)
We present an analysis of archival Chandra and XMM-Newton observations of the magnetically-active cataclysmic variable DQ Her and the shell around it ejected in a nova event in 1934. A careful revision of the Chandra observations confirms previous claims on the presence of extended X-ray emission around DQ Her and reveals that it actually corresponds to a bipolar jet-like structure extending $\simeq$32$''$ along a direction from NE to SW. Therefore, this X-ray emission extends beyond the optical nova shell and is perpendicular to its major axis. The XMM-Newton observations confirm the presence of the extended X-ray emission detected by Chandra, suggesting the additional presence of a diffuse X-ray emission from a hot bubble filling the nova shell. This hot bubble was very likely produced by the explosion that created the nebular shell detected in optical images. The bipolar feature can be modelled by the combination of an optically thin plasma emission component with temperature $T\approx2\times10^{6}$ K and a power law component with a photon index of $\Gamma=1.1\pm0.9$. Its X-ray luminosity in the 0.3 - 5 keV energy range is $L_\mathrm{X}=(2.1\pm1.3)\times10^{29}$ erg s$^{-1}$, for an electron density $n_\mathrm{e}\approx2$ cm$^{-3}$ and a mass $m_\mathrm{X}\approx 3\times10^{-6}$ M$_{\odot}$. We suggest that the X-ray bipolar structure in DQ Her is a jet and interpret its non-thermal X-ray emission in terms of a magnetized jet.
- [56] arXiv:2005.12119 [pdf, other]
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Title: Optimal Boltzmann hierarchies with non-vanishing spatial curvatureComments: 12 pages, 2 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Within cosmological perturbation theory, the cosmic microwave background anisotropies are usually computed from a Boltzmann hierarchy coupled to the perturbed Einstein equations. In this setup, one set of multipoles describes the temperature anisotropies, while two other sets, of electric and magnetic types, describe the polarization anisotropies. In order to reduce the number of multipoles types needed for polarization, and thus to speed up the numerical resolution, an optimal hierarchy has been proposed in the literature for Einstein-Boltzmann codes. However, it has been recently shown that the separability between directional and orbital eigenfunctions employed in the optimal hierarchy is not correct in the presence of spatial curvature. We investigate how the assumption of separability affects the optimal hierarchy, and show that it introduces relative errors of order $\Omega_K$ with respect to the full hierarchy. Despite of that, we show that the optimal hierarchy still gives extremely good results for temperature and polarization angular spectra, with relative errors that are much smaller than cosmic variance even for curvatures as large as $|\Omega_K|=0.1$. Still, we find that the polarization angular spectra from tensor perturbations are significantly altered when using the optimal hierarchy, leading to errors that are typically of order $50 |\Omega_K| \%$ on that component.
- [57] arXiv:2005.12127 [pdf, ps, other]
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Title: Analytical determination of the structure of the outer crust of a cold nonaccreted neutron star: extension to strongly quantizing magnetic fieldsComments: 13 pages. Accepted for publication in Physical Review C. A computer code is available on Zenodo at this http URLSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
The iterative method recently proposed for determining the internal constitution of the outer crust of a nonaccreted neutron star is extended to magnetars by taking into account the Landau-Rabi quantization of electron motion induced by the presence of a very high magnetic field. It is shown that in the strongly quantizing regime, the method can be efficiently implemented using new analytical solutions for the transitions between adjacent crustal layers. Detailed numerical computations are performed to assess the performance and precision of the method.
- [58] arXiv:2005.12135 [pdf, ps, other]
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Title: Artefacts of circumpolar cartography in radio pulsar polarizationAuthors: J. DyksComments: 5 pages, 3 figures, accepted by MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Single pulse data on radio pulsar polarization are traditionally presented in the form of two-dimentional greyscale patterns with the pulse longitude and polarization angle (PA) on the horizontal and vertical axis, respectively. Such diagrams reveal several enigmatic polarization effects: 1) bifurcations and loops of PA curve under central pulse components, 2) vertical spread of flux at all PA values, 3) exchange of power content between PA tracks of two orthogonal polarization modes (OPMs), and 4) peripherically-flat PA swings that span more than 180 degrees. It is shown that all these phenomena result from passage of observed polarization state near the pure-V pole of Poincare sphere. Much of their complexity results from cartographic transformation from Poincare sphere to the longitude-PA plane. An odd number of near-pole passage produces apparent replacement of OPMs power in the profile wings, although the same amount of flux keeps staying in each modal patch on the Poincare sphere. The fitting of pulsar PA curves should therefore allow for transitions between the primary (strong) and secondary (weak) PA track. The Stokes-space (or Poincare-sphere) representation of pulsar polarization data contains crucial polarization information and needs to accompany the traditional viewing if the published figures are to be fully useful for interpretation.
- [59] arXiv:2005.12152 [pdf, other]
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Title: Atmospheric circulation of brown dwarfs and directly imaged exoplanets driven by cloud radiative feedback: effects of rotationComments: Submitted to MNRAS, 22 pages, 16 figuresSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR); Atmospheric and Oceanic Physics (physics.ao-ph)
Observations of brown dwarfs (BDs), free-floating planetary-mass objects, and directly imaged extrasolar giant planets (EGPs) exhibit rich evidence of large-scale weather. Understanding the mechanisms driving the vigorous atmospheric circulation of BDs and directly imaged EGPs and its effects on their observed lightcurve variability and spectral properties is a pressing need. Our previous work has suggested a strong role of radiative cloud feedback on inducing a spontaneous time evolution in a simple one-dimensional framework. Yet the radiative cloud feedback in a three-dimensional (3D) dynamical framework remains unexplored for conditions relevant to these objects. Here we present a series of atmospheric circulation models that self-consistently couple dynamics with idealized cloud formation and its radiative effects. We demonstrate that vigorous atmospheric circulation can be triggered and self-maintained by cloud radiative feedback. The circulation is dominated by cloud-forming and clear-sky vortices that evolve over timescales from several to tens of hours. The typical horizontal lengthscales of dominant vortices are strongly constrained by the rotation, showing a linear dependence on the inverse of rotation rate with stronger rotation leading to thinner clouds. Domain-mean outgoing radiative flux exhibits variability over timescales of tens of hours due to the statistical evolution of storms. The circulation driven by cloud radiative feedback represents a natural mechanism generating significant surface inhomogeneity as well as irregular flux variability. Our results also have important implications for near-IR colors of dusty BDs and EGPs, including the scatter in the near-IR color-magnitude diagram and the viewing-geometry dependent near-IR colors.
- [60] arXiv:2005.12159 [pdf, ps, other]
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Title: Cosmological Information from the Small-scale Redshift Space DistortionsAuthors: Motonari Tonegawa, Changbom Park, Yi Zheng, Hyunbae Park, Sungwook E. Hong, Ho Seong Hwang, Juhan KimComments: 18 pages, 12 figures, accepted for publication in ApJSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The redshift-space distortion (RSD) in the observed distribution of galaxies is known as a powerful probe of cosmology. Observations of large-scale RSD have given tight constraints on the linear growth rate of the large-scale structures in the universe. On the other hand, the small-scale RSD, caused by galaxy random motions inside clusters, has not been much used in cosmology, but also has cosmological information because universes with different cosmological parameters have different halo mass functions and virialized velocities. We focus on the projected correlation function $w(r_p)$ and the multipole moments $\xi_l$ on small scales ($1.4$ to $30\ h^{-1}\rm{Mpc}$). Using simulated galaxy samples generated from a physically motivated most bound particle (MBP)-galaxy correspondence scheme in the Multiverse Simulation, we examine the dependence of the small-scale RSD on the cosmological matter density parameter $\Omega_m$, the satellite velocity bias with respect to MBPs, $b_v^s$, and the merger-time-scale parameter $\alpha$. We find that $\alpha=1.5$ gives an excellent fit to the $w(r_p)$ and $\xi_l$ measured from the SDSS-KIAS value added galaxy catalog. We also define the ``strength'' of Fingers-of-God as the ratio of the parallel and perpendicular size of the contour in the two-point correlation function set by a specific threshold value and show that the strength parameter helps constraining $(\Omega_m, b_v^s, \alpha)$ by breaking the degeneracy among them. The resulting parameter values from all measurements are $(\Omega_m,b_v^s)=(0.272\pm0.013,0.982\pm0.040)$, indicating a slight reduction of satellite galaxy velocity relative to the MBP. However, considering that the average MBP speed inside haloes is $0.94$ times the dark matter velocity dispersion, the main drivers behind the galaxy velocity bias are gravitational interactions, rather than baryonic effects.
- [61] arXiv:2005.12164 [pdf]
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Title: An X-Ray Burst from a Magnetar Enlightening the Mechanism of Fast Radio BurstsAuthors: M. Tavani, C. Casentini, A. Ursi, F. Verrecchia, A. Addis, L. A. Antonelli, A. Argan, G. Barbiellini, L. Baroncelli, G. Bernardi, G. Bianchi, A. Bulgarelli, P. Caraveo, M. Cardillo, P. W. Cattaneo, A. W. Chen, E. Costa, E. Del Monte, G. Di Cocco, G. Di Persio, I. Donnarumma, Y. Evangelista, M. Feroci, A. Ferrari, V. Fioretti, F. Fuschino, M. Galli, F. Gianotti, A. Giuliani, C. Labanti, F. Lazzarotto, P. Lipari, F. Longo, F. Lucarelli, A. Magro, M. Marisaldi, S. Mereghetti, E. Morelli, A. Morselli, G. Naldi, L. Pacciani, N. Parmiggiani, F. Paoletti, A. Pellizzoni, M. Perri, F. Perotti, G. Piano, P. Picozza, M. Pilia, C. Pittori, S. Puccetti, G. Pupillo, M. Rapisarda, A. Rappoldi, A. Rubini, G. Setti, P. Soffitta, M. Trifoglio, A. Trois, S. Vercellone, V. Vittorini, P. Giommi, F. D' AmicoComments: Submitted to Nature Astronomy, May 18, 2020Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Fast radio bursts (FRBs) are short (millisecond) radio pulses originating from enigmatic sources at extragalactic distances so far lacking a detection in other energy bands. Magnetized neutron stars (magnetars) have been considered as the sources powering the FRBs, but the connection is controversial because of differing energetics and the lack of radio and X-ray detections with similar characteristics in the two classes. We report here the detection by the AGILE satellite on April 28, 2020 of an X-ray burst in coincidence with the very bright radio burst from the Galactic magnetar SGR 1935+2154. The burst detected by AGILE in the hard X-ray band (18-60 keV) lasts about 0.5 seconds, it is spectrally cutoff above 80 keV, and implies an isotropically emitted energy ~ $10^{40}$ erg. This event is remarkable in many ways: it shows for the first time that a magnetar can produce X-ray bursts in coincidence with FRB-like radio bursts; it also suggests that FRBs associated with magnetars may emit X-ray bursts of both magnetospheric and radio-pulse types that may be discovered in nearby sources. Guided by this detection, we discuss SGR 1935+2154 in the context of FRBs, and especially focus on the class of repeating-FRBs. Based on energetics, magnetars with fields B ~ $10^{15}$ G may power the majority of repeating-FRBs. Nearby repeating-FRBs offer a unique occasion to consolidate the FRB-magnetar connection, and we present new data on the X-ray monitoring of nearby FRBs. Our detection enlightens and constrains the physical process leading to FRBs: contrary to previous expectations, high-brightness temperature radio emission coexists with spectrally-cutoff X-ray radiation.
- [62] arXiv:2005.12166 [pdf, other]
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Title: A model-free, data-based forecast for sunspot cycle 25Authors: Aleix Espuña-Fontcuberta (NORDITA), Saikat Chatterjee (KTH), Dhrubaditya Mitra (NORDITA), Dibyendu Nandy (CESSSI, IISER-K)Comments: 9 pages 3 figuresSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
The dynamic activity of the Sun, governed by its cycle of sunspots -- strongly magnetized regions that are observed on its surface -- modulate our solar system space environment creating space weather. Severe space weather leads to disruptions in satellite operations, telecommunications, electric power grids and air-traffic on polar routes. Forecasting the cycle of sunspots, however, has remained a challenging problem. We use reservoir computing -- a model-free, neural--network based machine-learning technique -- to forecast the upcoming solar cycle, sunspot cycle 25. The standard algorithm forecasts that solar cycle 25 is going to last about ten years, the maxima is going to appear in the year 2024 and the maximum number of sunspots is going to be 113 ($\pm15$). We also develop a novel variation of the standard algorithm whose forecasts for duration and peak timing matches that of the standard algorithm, but whose peak amplitude forecast is 124 ($\pm2$) -- within the upper bound of the standard reservoir computing algorithm. We conclude that sunspot cycle 25 is likely to be a weak, lower than average solar cycle, somewhat similar in strength to sunspot cycle 24.
- [63] arXiv:2005.12174 [pdf, other]
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Title: Measuring HERA's primary beam in-situ: methodology and first resultsAuthors: Chuneeta D. Nunhokee, Aaron R. Parsons, Nicholas S. Kern, Bojan Nikolic, Jonathan C. Pober, Gianni Bernardi, Chris L. Carilli, Zara Abdurashidova, James E. Aguirre, Paul Alexander, Zaki S. Ali, Yanga Balfour, Adam P. Beardsley, Tashalee S. Billings, Judd D. Bowman, Richard F. Bradley, Jacob Burba, Carina Cheng, David R. DeBoer, Matt Dexter, Eloy de~Lera~Acedo, Joshua S. Dillon, Aaron Ewall-Wice, Nicolas Fagnoni, Randall Fritz, Steve R. Furlanetto, Kingsley Gale-Sides, Brian Glendenning, Deepthi Gorthi, Bradley Greig, Jasper Grobbelaar, Ziyaad Halday, Bryna J. Hazelton, Jacqueline N. Hewitt, Daniel C. Jacobs, Austin Julius, Joshua Kerrigan, Piyanat Kittiwisit, Saul A. Kohn, Matthew Kolopanis, Adam Lanman, Paul La~Plante, Telalo Lekalake, Adrian Liu, David MacMahon, Lourence Malan, Cresshim Malgas, et al. (20 additional authors not shown)Comments: 22 pages, 22 figures, accepted for publication in ApJSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The central challenge in 21~cm cosmology is isolating the cosmological signal from bright foregrounds. Many separation techniques rely on the accurate knowledge of the sky and the instrumental response, including the antenna primary beam. For drift-scan telescopes such as the Hydrogen Epoch of Reionization Array \citep[HERA, ][]{DeBoer2017} that do not move, primary beam characterization is particularly challenging because standard beam-calibration routines do not apply \citep{Cornwell2005} and current techniques require accurate source catalogs at the telescope resolution. We present an extension of the method from \citet{Pober2012} where they use beam symmetries to create a network of overlapping source tracks that break the degeneracy between source flux density and beam response and allow their simultaneous estimation. We fit the beam response of our instrument using early HERA observations and find that our results agree well with electromagnetic simulations down to a -20~dB level in power relative to peak gain for sources with high signal-to-noise ratio. In addition, we construct a source catalog with 90 sources down to a flux density of 1.4~Jy at 151~MHz.
- [64] arXiv:2005.12177 [pdf, other]
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Title: The Role of Inhomogeneities in Supernova Shock Breakout EmissionAuthors: Chris L. Fryer, Christopher J. Fontes, James S. Warsa, Pete W. A. Roming, Shane X. Coffing, Suzannah R. WoodComments: 14 pages, 12 figures, submitted to ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
The breakout of a supernova blast wave from its progenitor star provides strong constraints on the star and its immediate surroundings. These surroundings are shaped by mass loss from the star and can include a wide variety of inhomogeneities. Here we present results of multi-dimensional radiation-hydrodynamics calculations of the interactions of the supernova blast wave with inhomogeneities in the immediate surroundings of a massive Wolf-Rayet star, calculating the effect these interactions have on the shock breakout signal from supernovae.
- [65] arXiv:2005.12180 [pdf, other]
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Title: Solar Flare Prediction Using Magnetic Field Diagnostics Above the PhotosphereAuthors: M. B. Korsos, M. K. Georgoulis, N. Gyenge, S. K. Bisoi, S. Yu, S. Poedts, C. J. Nelson, J. Liu, Y. Yan, R. ErdelyiSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
In this article, we present the application of the weighted horizontal gradient of magnetic field (WGM) flare prediction method to 3-dimensional (3D) extrapolated magnetic configurations of 13 flaring solar active regions (ARs). The main aim is to identify an optimal height range, if any, in the interface region between the photosphere and lower corona, where the flare onset time prediction capability of WGM is best exploited. The optimal height is where flare prediction, by means of the WGM method, is achieved earlier than at the photospheric level. 3D magnetic structures, based on potential and non-linear force-free field extrapolations, are constructed to study a vertical range from the photosphere up to the low corona with a 45 km step size. The WGM method is applied as a function of height to all 13 flaring AR cases that are subject to certain selection criteria. We found that applying the WGM method between 1000 and 1800 km above the solar surface would improve the prediction of the flare onset time by around 2-8 hours.Certain caveats and an outlook for future work along these lines are also discussed.
- [66] arXiv:2005.12184 [pdf, other]
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Title: On the road to per-cent accuracy IV: ReACT -- computing the non-linear power spectrum beyond $Λ$CDMAuthors: Benjamin Bose, Matteo Cataneo, Tilman Tröster, Qianli Xia, Catherine Heymans, Lucas LombriserComments: 13 pages, 5 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
To effectively exploit large-scale structure surveys, we depend on accurate and reliable predictions of non-linear cosmological structure formation. Tools for efficient and comprehensive computational modelling are therefore essential to perform cosmological parameter inference analyses. We present the public software package ReACT, demonstrating its capability for the fast and accurate calculation of non-linear power spectra from non-standard physics. We showcase ReACT through a series of forecast constraints on the DGP and $f(R)$ gravity models, adopting LSST-like cosmic shear power spectra. Accurate non-linear modelling with ReACT more than doubles LSST's constraining power on the $f(R)$ parameter, in contrast to an analysis that is limited to the quasi-linear regime. We find that ReACT is sufficiently robust for the inference of consistent constraints on theories beyond $\Lambda$CDM for current and ongoing surveys. With further improvement, particularly in terms of the accuracy of the non-linear $\Lambda$CDM power spectrum, ReACT can, in principle, meet the accuracy requirements for future surveys such as Euclid and LSST.
- [67] arXiv:2005.12201 [pdf, ps, other]
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Title: Black Hole Spin Energy Contribution to Black Hole Mass and the Spin Energy ReservoirAuthors: Ruth A. DalyComments: 13 pages, 7 figures, 1 tableSubjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
The mass of a black hole is the sum of the irreducible mass and the mass associated with the rotational or spin energy of the black hole. The contribution of spin energy (divided by $c^2$) to the total black hole mass is studied here for four samples of sources including 576 LINERs, 100 classical double radio sources, 80 relatively local AGN, and 102 measurements of four stellar mass X-ray binary systems. The spin mass-energy of a black hole may be extracted causing the mass of the black hole to decrease. The ratio of spin mass-energy to black hole mass ranges from about ten to thirty percent for the sources studied here, where the maximum possible value of this quantity is close to thirty percent. Typical fractions of the black hole mass available for extraction for the samples studied are about $0.2 \pm 0.1$. The spin energy of black holes represents a major reservoir that when tapped may impact the immediate and extended black hole environment, decrease the black hole mass, and perhaps modify relationships between black hole mass and galaxy properties. These results are consistent with expectations based on other observations and numerical simulations.
- [68] arXiv:2005.12222 [pdf, other]
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Title: Extended reionization in models beyond $Λ$CDM with Planck 2018 dataComments: 19 pages, 16 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We provide an update on the constraints on extended reionization histories with the Planck 2018 cosmic microwave background anisotropy data. The Planck 2018 data on large angular scales improve the measurement of the $E$-mode polarization reionization bump at low multipoles providing the possibility to improve our previous results. Using a minor modification to the original Poly-reion model for the reionization history, we find that the Planck 2018 data significantly improve all our previous results: we find as optical depth of $\tau=0.0572_{-0.0075}^{+0.0064}$ at 68% CL, that early onsets of reionization are strongly disfavoured, i.e. redshift when the reionization begins, $z_{xe=0}=18.18_{-10.89}^{+1.61}$ at 68% CL,and that reionization duration (defined between 10% and 99% reionization) is significantly reduced, i.e. $\Delta_z^{Reion}=4.59_{-2.45}^{+1.67}$ at 68% CL. We explore possible correlations between reionization histories and cosmological parameters, including important extensions beyond $\Lambda$CDM. We find that the degeneracy between reionization and scalar spectral index,neutrino mass sum, spatial curvature, dark matter annihilation and other non-standard models are significantly reduced.The reduction of the error bars and the degeneracies, together with the shift towards lower values of the optical depth that we observe in the Poly-reion model are mainly driven by the new low-$\ell$ polarization likelihood of Planck 2018 baseline based on the HFI data. This is confirmed also by the results derived without this likelihood and the ones with different alternatives to the baseline that are presented for a subset of models.
Cross-lists for Tue, 26 May 20
- [69] arXiv:2005.10543 (cross-list from nucl-th) [pdf, other]
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Title: Neutron stars with large quark coresComments: 16 pages, 15 figuresSubjects: Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
We describe charge-neutral neutron star matter in $\beta-$equilibrium using hybrid equations of state, where a first-order phase transition from hadronic to quark matter is realized. The hadronic matter is described in a model-independent way by a Taylor expansion around saturation density $n_0$, while the three-flavor NJL model is used for the quark matter. Exploring the present uncertainty on the empirical parameters of nuclear matter and the parameter space of the NJL model, we construct two datasets of thermodynamically consistent and causal hybrid EoSs, compatible with astrophysical observations. We conclude that, to sustain a considerable quark core size, the intensity of the phase transition from hadron to quark matter cannot be strong, having a energy density gap below $200$ MeV/fm$^3$, and must occur at baryon densities not above four times the saturation density. A non zero but not too strong quark vector-isoscalar term and a weak vector isovector quark term are required. Large quark cores carrying almost half of the star mass are possible inside neutron stars with a maximum mass $\approx 2.2 M_\odot$. To get a considerable number of hybrid EoS predicting quark matter already inside neutron stars with a mass $\sim 1.4 M_\odot$, we require that the onset of quarks occurs in the range $1.3n_0$ and $2.5n_0$. Neutron stars with large quark cores corresponding to more than one fourth of the total star mass, are possible if the energy density gap and the pressure at transition are below 100 MeV/fm$^3$. However, under these constraints, the maximum neutron star mass is limited to $M_{\odot}\lesssim 2.06$. No strong signatures from quark matter were found on the radius and the tidal deformability for neutron star masses below $1.8\, M_\odot$.
- [70] arXiv:2005.11328 (cross-list from hep-ph) [pdf, other]
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Title: Cosmic Inflation in Minimal $U(1)_{B-L}$ Model: Implications for (Non) Thermal Dark Matter and LeptogenesisComments: 45 pages, 19 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We study the possibility of realising cosmic inflation, dark matter (DM), baryon asymmetry of the universe (BAU) and light neutrino masses in minimal gauged $B-L$ extension of the standard model with three right handed neutrinos. The singlet scalar field responsible for spontaneous breaking of $B-L$ gauge symmetry also plays the role of inflaton by virtue of its non-minimal coupling to gravity. While the lightest right handed neutrino is the DM candidate, being stabilised by an additional $Z_2$ symmetry, we show by performing a detailed renormalisation group evolution (RGE) improved study of inflationary dynamics that thermal DM is generally overproduced due to insufficient annihilations through gauge and scalar portals. The non-thermal DM scenario is viable, with or without $Z_2$ symmetry, although in such a case the $B-L$ gauge sector remains decoupled from the inflationary dynamics due to tiny couplings. We also show that the reheat temperature predicted by the model prefers non-thermal leptogenesis while being consistent with light neutrino data as well as non-thermal DM scenario.
- [71] arXiv:2005.11337 (cross-list from physics.space-ph) [pdf, other]
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Title: Assessment of the Performance of Ionospheric Models with NavIC Observations during Geomagnetic StormsComments: 4 pages, 4 figures, accepted for publication in the proceedings of the 2020 URSI Regional Conference on Radio Science(URSI-RCRS 2020)Subjects: Space Physics (physics.space-ph); Solar and Stellar Astrophysics (astro-ph.SR)
The paper presents an assessment of the performances of the global empirical models: International Reference Ionosphere (IRI)-2016 and the NeQuick2 model derived ionospheric Total Electron Content (TEC) with respect to the Navigation with Indian Constellation (NavIC)/ Indian Regional Navigation Satellite System(IRNSS) estimated TEC under geomagnetic storm conditions. The present study is carried out over Indore (Geographic: 22.52$^{\circ}$N 75.92$^{\circ}$E and Magnetic Dip: 32.23$^{\circ}$N, located close to the northern crest of the Equatorial Ionization Anomaly (EIA) region of the Indian sector). Analysis has been performed for an intense storm (September 6-10, 2017), a moderate storm (September 26-30, 2017) and a mild storm (January 17-21, 2018) that fall in the declining phase of the present solar cycle. It is observed that both IRI-2016 and NeQuick2 derived TEC are underestimates when compared with the observed TEC from NavIC and therefore fail to predict storm time changes in TEC over this region and requires real data inclusion from NavIC for better prediction over the variable Indian longitude sector.
- [72] arXiv:2005.11563 (cross-list from hep-ph) [pdf, ps, other]
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Title: Constraints on light dark matter particles using white dwarf starsComments: 11 pages, 2 tables, 2 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
We report constraints on the nucleon-dark matter particle cross section using the internal luminosity of observed white dwarf stars in the globular cluster Messier 4. Our results cover the parameter space corresponding to relatively light dark matter particles, in the mass range $0.1~GeV-5~GeV$, which is known to be very difficult to be probed by direct dark matter searches. The additional luminosity coming from self-annihilations of dark matter particles captured inside the stars must not exceed the observed luminosity. Imposing that condition, we obtain for the spin independent cross section of light dark matter particles on baryons $\sigma_{N\chi}$ the upper bound: $\sigma_{N\chi} < 4 \times 10^{-41}{\rm cm^2}$.
- [73] arXiv:2005.11629 (cross-list from gr-qc) [pdf, ps, other]
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Title: Inverse-Chirp Imprint of Gravitational Wave Signals in Scalar Tensor TheoryComments: 12 pages, 4 figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The scalar tensor theory contains a coupling function connecting the quantities in the Jordan and Einstein frames, which is constrained to guarantee a transformation rule between frames. We simulate the supernovae core collapse with different choices of coupling functions defined over the viable region of the parameter space and find that a generic inverse-chirp feature of the gravitational waves in the scalar tensor scenario.
- [74] arXiv:2005.11891 (cross-list from hep-ex) [pdf, ps, other]
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Title: Search for exotic neutrino-electron interactions using solar neutrinos in XMASS-IAuthors: XMASS collaboration: K. Abe, Y. Chen, K. Hiraide, K. Ichimura, S. Imaizumi, N. Kato, K. Kobayashia, M. Kobayashi, S. Moriyama, M. Nakahata, K. Sato, H. Sekiya, T. Suzuki, A. Takeda, S. Tasaka, M. Yamashita, B. S. Yang, N. Y. Kim, Y. D. Kim, Y. H. Kim, R. Ishii, Y. Itow, K. Kanzawa, K. Martens, A. Mason, Y. Suzuki, K. Miuchi, Y. Takeuchi, K. B. Lee, M. K. Lee, Y. Fukuda, H. Ogawa, Y. Kishimoto, K. Nishijima, K. Fushimi, B. D. Xu, S. NakamuraSubjects: High Energy Physics - Experiment (hep-ex); High Energy Astrophysical Phenomena (astro-ph.HE)
We have searched for exotic neutrino-electron interactions that could be produced by a neutrino millicharge, by a neutrino magnetic moment, or by dark photons using solar neutrinos in the XMASS-I liquid xenon detector. We observed no significant signals in 711 days of data. We obtain an upper limit for neutrino millicharge of 5.4$\times$10$^{-12} e$ at 90\% confidence level assuming all three species of neutrino have common millicharge. We also set flavor dependent limits assuming the respective neutrino flavor is the only one carrying a millicharge, $7.3 \times 10^{-12} e$ for $\nu_e$, $1.1 \times 10^{-11} e$ for $\nu_{\mu}$, and $1.1 \times 10^{-11} e$ for $\nu_{\tau}$. These limits are the most stringent yet obtained from direct measurements. We also obtain an upper limit for the neutrino magnetic moment of 1.8$\times$10$^{-10}$ Bohr magnetons. In addition, we obtain upper limits for the coupling constant of dark photons in the $U(1)_{B-L}$ model of 1.3$\times$10$^{-6}$ if the dark photon mass is 1$\times 10^{-3}$ MeV$/c^{2}$, and 8.8$\times$10$^{-5}$ if it is 10 MeV$/c^{2}$.
Replacements for Tue, 26 May 20
- [75] arXiv:1906.05371 (replaced) [pdf, other]
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Title: Streaming Instability in Turbulent Protoplanetary DisksComments: Accepted to ApJ, April 14, 2020Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
- [76] arXiv:1907.08638 (replaced) [pdf, other]
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Title: Galaxy-lens determination of $H_0$: constraining density slope in the context of the mass sheet degeneracyComments: 36 pages, 11 figures, submitted to JCAPSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)
- [77] arXiv:1907.12509 (replaced) [pdf, other]
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Title: Velocity independent constraints on spin-dependent DM-nucleon interactions from IceCube and PICOAuthors: IceCube Collaboration: M. G. Aartsen, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, C. Alispach, K. Andeen, T. Anderson, I. Ansseau, G. Anton, C. Argüelles, J. Auffenberg, S. Axani, P. Backes, H. Bagherpour, X. Bai, A. Balagopal V., A. Barbano, S. W. Barwick, B. Bastian, V. Baum, S. Baur, R. Bay, J. J. Beatty, K.-H. Becker, J. Becker Tjus, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, C. Bohm, M. Börner, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, J. Bourbeau, F. Bradascio, J. Braun, S. Bron, J. Brostean-Kaiser, A. Burgman, J. Buscher, R. S. Busse, T. Carver, C. Chen, E. Cheung, D. Chirkin, S. Choi, L. Classen, A. Coleman, G. H. Collin, J. M. Conrad, P. Coppin, P. Correa, D. F. Cowen, R. Cross, P. Dave, et al. (358 additional authors not shown)Comments: 9 pages, 3 figures, 1 table. To appear in Eur.Phys.J. CSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [78] arXiv:1908.04830 (replaced) [pdf, ps, other]
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Title: Gravity theory with a dark extra dimensionAuthors: Sandipan SenguptaComments: Version identical with the one to be published; Title changedJournal-ref: Phys. Rev. D 101, 104040 (2020)Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics of Galaxies (astro-ph.GA); High Energy Physics - Theory (hep-th)
- [79] arXiv:1909.13505 (replaced) [pdf, ps, other]
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Title: Understanding the Discrepancy between IRX and Balmer Decrement in Tracing Galaxy Dust AttenuationAuthors: Jianbo Qin (1), Xian Zhong Zheng (1), Stijn Wuyts (2), Zhizheng Pan (1), Jian Ren (1) ((1) Purple Mountain Observatory, CAS, (2) University of Bath)Comments: 9 pages, 5 figures, Accepted for publication in ApJSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [80] arXiv:1910.02763 (replaced) [pdf, other]
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Title: Constraining coupled quintessence with the 21cm signalComments: 16 pages, 7 figures, 3 tablesJournal-ref: JCAP05(2020)038Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [81] arXiv:1910.04097 (replaced) [pdf, ps, other]
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Title: Less noticeable shallow decay phase in early X-ray afterglows of GeV/TeV-detected gamma-ray burstsComments: 12 pages, 6 figures, 3 tables. MNRAS, 494, 5259 (2020)Journal-ref: MNRAS, 494, 5259 (2020)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [82] arXiv:1910.10927 (replaced) [pdf, other]
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Title: Large Population of ALMA Galaxies at z>6 with Very High [OIII]88um to [CII]158um Flux Ratios: Evidence of Extremely High Ionization Parameter or PDR Deficit?Authors: Yuichi Harikane, Masami Ouchi, Akio K. Inoue, Yoshiki Matsuoka, Yoichi Tamura, Tom Bakx, Seiji Fujimoto, Kana Moriwaki, Yoshiaki Ono, Tohru Nagao, Ken-ichi Tadaki, Takashi Kojima, Takatoshi Shibuya, Eiichi Egami, Andrea Ferrara, Simona Gallerani, Takuya Hashimoto, Kotaro Kohno, Yuichi Matsuda, Hiroshi Matsuo, Andrea Pallottini, Yuma Sugahara, Livia ValliniComments: 20 pages, 18 figures, Accepted for publication in ApJSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [83] arXiv:1910.12971 (replaced) [pdf, other]
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Title: Neutrino emission characteristics of black hole formation in three-dimensional simulations of stellar collapseAuthors: Laurie Walk, Irene Tamborra (Niels Bohr Institute), Hans-Thomas Janka, Alexander Summa, Daniel Kresse (MPA, Garching)Comments: 25 pages, including 19 figures. Discussion on LESA expanded; conclusions unchanged. Matches version accepted for publication in Phys. Rev. D. Animated visualizations available at: this https URLSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
- [84] arXiv:1910.13370 (replaced) [pdf, other]
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Title: Particle acceleration in kink-unstable jetsComments: 9 pages, 5 figures, accepted for publication in ApJLSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Plasma Physics (physics.plasm-ph)
- [85] arXiv:1910.14649 (replaced) [pdf, other]
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Title: Spiral galaxies and their dark halos as self-organized patternsComments: 6 pages, 4 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA); Statistical Mechanics (cond-mat.stat-mech); Pattern Formation and Solitons (nlin.PS)
- [86] arXiv:1910.14669 (replaced) [pdf, other]
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Title: Searching for Dark Photon Dark Matter with Cosmic Ray AntideuteronsComments: 22 pages, 21 figures. Matches version accepted by JHEPJournal-ref: J. High Energ. Phys. 2020, 81 (2020)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE)
- [87] arXiv:1911.02667 (replaced) [pdf, other]
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Title: Higher Order Hamiltonian Monte Carlo Sampling for Cosmological Large-Scale Structure AnalysisComments: 17 pages, 10 figures, 4 tablesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Lattice (hep-lat)
- [88] arXiv:1911.04830 (replaced) [pdf, other]
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Title: Thermodynamics of $f(R)$ Theories of GravityComments: 13 pages, 11 figures. Matches version accepted for publication in JCAPSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [89] arXiv:1911.13158 (replaced) [pdf, other]
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Title: THOR 2.0: Major Improvements to the Open-Source General Circulation ModelAuthors: Russell Deitrick, João M. Mendonça, Urs Schroffenegger, Simon L. Grimm, Shang-Min Tsai, Kevin HengComments: 57 pages, 31 figures, revised, accepted for publication in ApJSSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [90] arXiv:1912.02837 (replaced) [pdf, other]
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Title: The BAT AGN Spectroscopic Survey -- XVIII. Searching for Supermassive Black Hole Binaries in the X-raysAuthors: Tingting Liu, Michael Koss, Laura Blecha, Claudio Ricci, Benny Trakhtenbrot, Richard Mushotzky, Fiona Harrison, Kohei Ichikawa, Darshan Kakkad, Kyuseok Oh, Meredith Powell, George C. Privon, Kevin Schawinski, T. Taro Shimizu, Krista Lynne Smith, Daniel Stern, Ezequiel Treister, C. Megan UrryComments: 17 pages, including 8 figures and 4 tables. Accepted for publication in ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [91] arXiv:1912.03599 (replaced) [pdf, other]
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Title: Weighing in on black hole binaries with BPASS: LB-1 does not contain a 70M$_{\odot}$ black holeComments: Accepted for MNRAS, 10 pages, 5 figures, 3 tablesSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
- [92] arXiv:2001.05980 (replaced) [pdf, other]
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Title: Prospects for discovering supersymmetric long-lived particles with MoEDALAuthors: D. Felea, J. Mamuzic, R. Masełek, N. E. Mavromatos, V. A. Mitsou, J. L. Pinfold, R. Ruiz de Austri, K. Sakurai, A. Santra, O. VivesComments: 12 pages, 6 figures; preliminary results presented in arXiv:1903.11022; matches published version in EPJCJournal-ref: Eur.Phys.J.C 80 (2020) 5, 431Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Experiment (hep-ex)
- [93] arXiv:2001.08760 (replaced) [pdf, other]
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Title: Voronoi volume function: A new probe of cosmology and galaxy evolutionComments: 20 pages, 15 figures; v2 - minor changes to match version accepted in MNRASSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)
- [94] arXiv:2002.02463 (replaced) [pdf, other]
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Title: Relaxing the Higgs mass and its vacuum energy by living at the top of the potentialComments: 14 pages, 3 figures; published versionSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
- [95] arXiv:2002.04856 (replaced) [pdf, other]
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Title: Vacuum decay in the presence of a cosmic stringComments: 21 pages, 5 figuresJournal-ref: Phys.Rev.D 101 (2020) 10, 104036Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
- [96] arXiv:2002.11091 (replaced) [pdf, other]
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Title: Precise determination of the inflationary epoch and constraints for reheatingAuthors: Gabriel GermanComments: 16 pages, 5 figures. Section IV has been substituted and more emphasis on the diagrammatic approach is given. Version sent for publicationSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
- [97] arXiv:2002.11118 (replaced) [pdf, other]
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Title: Physics of Tidal Dissipation in Early-Type Stars and White Dwarfs: Hydrodynamical Simulations of Internal Gravity Wave Breaking in Stellar EnvelopesComments: 14 pages, 10 figures, accepted to MNRASJournal-ref: Mon. Not. R. Astron. Soc. 495 (2020) 1239-1251Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Fluid Dynamics (physics.flu-dyn)
- [98] arXiv:2003.04320 (replaced) [pdf, other]
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Title: The impact of fallback on the compact remnants and chemical yields of core-collapse supernovaeComments: 12 pages, 13 figures, accepted for publication in MNRASSubjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)
- [99] arXiv:2003.05795 (replaced) [pdf, other]
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Title: A Wind-Driven Model: Application to Peculiar Transients AT2018cow and iPTF14hlsComments: 13 pages, 10 figures, accepted for publication in the ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
- [100] arXiv:2003.07284 (replaced) [pdf, ps, other]
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Title: Application of a helicity proxy to edge-on galaxiesComments: 12 pages, 11 figures, 2 tables, submitted to MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [101] arXiv:2003.08832 (replaced) [pdf, other]
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Title: Galaxy rotation curves from external influence on Schwarzschild geometryAuthors: A. BhattacharyayComments: 8 pages and 1 figure. The present version includes, on top of what was shown in the previous version, a derivation to show that the generalized metric corresponds to a field which has its pressure proportional to its densitySubjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics of Galaxies (astro-ph.GA)
- [102] arXiv:2003.10498 (replaced) [pdf, other]
- [103] arXiv:2003.10503 (replaced) [pdf, other]
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Title: A mildly relativistic outflow from the energetic, fast-rising blue optical transient CSS161010 in a dwarf galaxyAuthors: D.L. Coppejans, R. Margutti, G. Terreran, A.J. Nayana, E.R. Coughlin, T. Laskar, K.D. Alexander, M. Bietenholz, D. Caprioli, P. Chandra, M. Drout, D. Frederiks, C. Frohmaier, K. Hurley, C.S. Kochanek, M. MacLeod, A. Meisner, P.E. Nugent, A. Ridnaia, D.J. Sand, D. Svinkin, C. Ward, S. Yang, A. Baldeschi, I.V. Chilingarian, Y. Dong, C. Esquivia, W. Fong, C. Guidorzi, P. Lundqvist, D. Milisavljevic, K. Paterson, D.E. Reichart, B. Shappee, M.C. Stroh, S. Valenti, A. Zauderer, B. ZhangComments: Accepted to ApJLSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [104] arXiv:2003.13625 (replaced) [pdf, other]
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Title: SDSS-IV MaNGA: Stellar population correlates with stellar root-mean-square velocity $V_{\rm rms}$ gradients or total-density-profile slopes at fixed effective velocity dispersion $σ_{\rm e}$Comments: 8 pages, 6 figures; Accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [105] arXiv:2003.14178 (replaced) [pdf, ps, other]
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Title: Hemispheric handedness in the Galactic synchrotron polarization foregroundComments: 7 pages, 4 figures, 1 table, submitted to ApJLSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [106] arXiv:2004.04083 (replaced) [pdf, other]
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Title: A very young radio-loud magnetarAuthors: P. Esposito, N.Rea, A. Borghese, F. Coti Zelati, D.Viganò, G. L. Israel, A.Tiengo, A. Ridolfi, A. Possenti, M. Burgay, D. Götz, F. Pintore, L. Stella, C. Dehman, M. Ronchi, S. Campana, A. Garcia-Garcia, V. Graber, S. Mereghetti, R. Perna, G. A. Rodríguez Castillo, R. Turolla, S. ZaneComments: 10 pages, 4 figures, 1 table; revised version accepted for publication in The Astrophysical Journal LettersSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [107] arXiv:2004.04185 (replaced) [pdf, other]
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Title: Photochemistry of Anoxic Abiotic Habitable Planet Atmospheres: Impact of New H$_2$O Cross-SectionsAuthors: Sukrit Ranjan, Edward W. Schwieterman, Chester Harman, Alexander Fateev, Clara Sousa-Silva, Sara Seager, Renyu HuComments: Manuscript (this version) accepted to ApJ. Cross-section data available at this https URL Feedback continues to be solicitedSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [108] arXiv:2004.04253 (replaced) [pdf, ps, other]
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Title: Extragalactic cosmic rays diffusing from two populations of sourcesComments: matches published versonJournal-ref: Physical Review D 101, 103024 (2020)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [109] arXiv:2004.05765 (replaced) [pdf, ps, other]
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Title: Particle acceleration in a shock wave propagating to an inhomogeneous mediumComments: 8 pages, 4 figures, 1 table, results and discussion updated. Accepted for publication in ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [110] arXiv:2004.06449 (replaced) [pdf, other]
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Title: H$_2$ content of galaxies inside and around intermediate redshift clustersAuthors: Damien Spérone-LonginComments: 5 pages, 4 figures, Proceedings of IAUS 359, Storchi-Bergmann et al. edSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [111] arXiv:2004.07315 (replaced) [pdf, other]
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Title: Hard Synchrotron Spectra from Magnetically Dominated Plasma TurbulenceComments: Accepted for publication in The Astrophysical Journal LettersSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Plasma Physics (physics.plasm-ph)
- [112] arXiv:2004.07907 (replaced) [pdf, other]
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Title: Supermassive black holes as possible sources of ultra high energy cosmic raysComments: 14 pages, 6 figuresJournal-ref: ApJ 895, 14 (2020)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
- [113] arXiv:2004.09818 (replaced) [pdf, other]
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Title: The assembly history of the nearest S0 galaxy NGC 3115 from its kinematics out to six half-light radiiAuthors: Arianna Dolfi, Duncan A. Forbes, Warrick J. Couch, Anna Ferre-Mateu, Sabine Bellstedt, Kenji Bekki, Jonathan Diaz, Aaron J. Romanowsky, Jean P. BrodieComments: 22 pages (including 3 pages of Appendix material), 14 figures, published in MNRASJournal-ref: MNRAS 495, 1321-1339 (2020)Subjects: Astrophysics of Galaxies (astro-ph.GA)
- [114] arXiv:2004.10205 (replaced) [pdf, other]
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Title: Merging Compact Binaries Near a Rotating Supermassive Black Hole: Eccentricity Excitation due to Apsidal Precession ResonanceComments: 12 pages, 9 figures, 1 appendixSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
- [115] arXiv:2004.12808 (replaced) [pdf, ps, other]
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Title: To power the X-ray plateaus of gamma-ray bursts through larger amplitude electromagnetic wavesAuthors: Shuang DuComments: 8 pages, 2 figures, ApJ submitted on 16-Mar-2020Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
- [116] arXiv:2004.13739 (replaced) [pdf, other]
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Title: A Detailed View of the Circumstellar Environment and Disk of the Forming O-star AFGL 4176Authors: K. G. Johnston, M. G. Hoare, H. Beuther, H. Linz, P. Boley, R. Kuiper, N. D. Kee, T. P. RobitailleComments: Accepted for publication in The Astrophysical Journal, 50 pages, 26 figures. Data available online at this http URLSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
- [117] arXiv:2004.14380 (replaced) [pdf, other]
- [118] arXiv:2005.02278 (replaced) [pdf, other]
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Title: Measuring the expansion of the universeAuthors: Gabriel GermanComments: 13 pages, 4 figures, 1 table. A new section has been added. Improved presentation. Misprints in Table I have been corrected. Version sent for publicationSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [119] arXiv:2005.02343 (replaced) [pdf, other]
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Title: Observing Left-Right Symmetry in the Cosmic Microwave BackgroundComments: 28 pages, 8 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [120] arXiv:2005.03050 (replaced) [pdf, other]
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Title: Nonlinear 3D Cosmic Web Simulation with Heavy-Tailed Generative Adversarial NetworksComments: 18 pages, 17 figures. v2: Corrected small typographic error in textSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Computational Physics (physics.comp-ph)
- [121] arXiv:2005.04807 (replaced) [pdf, other]
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Title: Basis function expansions for galactic dynamics: Spherical versus cylindrical coordinatesComments: 14 pages, 17 figures, Accepted for publication in A&ASubjects: Astrophysics of Galaxies (astro-ph.GA)
- [122] arXiv:2005.08029 (replaced) [pdf, other]
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Title: Windowing Artifacts Likely Account for Recent Claimed Detection of Oscillating Cosmic Scale FactorSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE)
- [123] arXiv:2005.08428 (replaced) [pdf, ps, other]
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Title: Cosmology and gravitational waves in consistent $D\to 4$ Einstein-Gauss-Bonnet gravityComments: 14 pages, no figures, updated discussionSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
- [124] arXiv:2005.09289 (replaced) [pdf, other]
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Title: Machine learning for gravitational-wave detection: surrogate Wiener filtering for the prediction and optimized cancellation of Newtonian noise at VirgoAuthors: F Badaracco, J Harms, A Bertolini, T Bulik, I Fiori, B Idzkowski, A Kutynia, K Nikliborc, F Paoletti, A Paoli, L Rei, M SuchinskiSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
- [125] arXiv:2005.09667 (replaced) [pdf, other]
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Title: Effective Opacity of the Intergalactic Medium from Galaxy Spectra AnalysisComments: accepted to ApJ on 05/18/2020Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [126] arXiv:2005.10778 (replaced) [pdf, other]
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Title: Cloud structures in M17 SWex : Possible cloud-cloud collisionAuthors: Shinichi W. Kinoshita, Fumitaka Nakamura, Quang Nguyen-Luong, Benjamin Wu, Tomomi Shimoikura, Koji Sugitani, Kazuhito Dobashi, Hideaki Takemura, Patricio Sanhueza, Kee-Tae Kim, Hyunwoo Kang, Neal J. Evans, Glenn J. White, Cassandra FallscheerComments: 34 pages, 13 figures, Accepted for publication in PASJSubjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
- [127] arXiv:2005.11109 (replaced) [pdf, ps, other]
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Title: On the Distance of SGR 1935+2154 Associated with FRB 200428Comments: 7 pages in emulateapj format, 3 figures, one typo correctedSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
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