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New submissions for Thu, 5 Mar 20

[1]  arXiv:2003.01720 [pdf, other]

Title: Origin of (2014) MU69-like Kuiper-belt contact binaries from wide binaries

Authors: Evgeni Grishin, Uri Malamud, Hagai B. Perets, Oliver Wandel, Christoph M. Schaefer

Comments: Submitted on 27 June 2019

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

Following its flyby and first imaging the Pluto-Charon binary, the New Horizons spacecraft visited the Kuiper-Belt-Object (KBO) (486958) 2014 MU69 (Arrokoth). Imaging showed MU69 to be a contact-binary, made of two individual lobes connected by a narrow neck, rotating at low spin period (15.92 h), and having high obliquity (~98 deg), similar to other KBO contact-binaries inferred through photometric observations. The origin of such peculiar configurations is puzzling, and all scenarios suggested for the origins of contact-binaries fail to reproduce such properties and their likely high frequency. Here we show that semi-secular perturbations operating only on ultra-wide (~0.1-0.4 Hill-radius) KBO-binaries can robustly lead to gentle, slow-speed binary mergers at arbitrarily high obliquities, but low rotational velocities, that can reproduce MU69's (and similar oblique contact binaries) characteristics. Using N-body simulations, we find that ~15% of all ultra-wide binaries with cosine-uniform inclination distribution are likely to merge through this process. Moreover, we find that such mergers are sufficiently gentle as to only slightly deform the KBO shape, and can produce the measured rotation speed of MU69. The semi-secular contact-binary formation channel not only explains the observed properties of MU69, but could also apply for other Kuiper/asteroid belt binaries, and for Solar/extra-solar moon systems.

[2]  arXiv:2003.01721 [pdf, ps, other]

Title: Observational constraints on the origin of the elements. III. Evidence for the dominant role of sub-Chandrasekhar SN Ia in the chemical evolution of Mn and Fe in the Galaxy

Authors: Philipp Eitner, Maria Bergemann, Camilla Juul Hansen, Gabriele Cescutti, Ivo Seitenzahl, Soeren Larsen, Bertrand Plez

Comments: 8 pages, A&A in press

Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

The abundance ratios of manganese to iron in late-type stars across a wide metallicity range place tight constraints on the astrophysical production sites of Fe-group elements. In this work, we investigate the chemical evolution of Mn in the Milky Way galaxy using high-resolution spectroscopic observations of stars in the Galactic disc and halo stars, as well as a sample of globular clusters. Our analysis shows that local thermodynamic equilibrium (LTE) leads to a strong imbalance in the ionisation equilibrium of Mn I and Mn II lines. Mn I produces systematically (up to 0.6 dex) lower abundances compared to the Mn II lines. Non-local thermodynamic equilibrium (NLTE) radiative transfer satisfies the ionisation equilibrium across the entire metallicity range, -3 < [Fe/H] < -1, leading to consistent abundances from both ionisation stages of the element. We compare the NLTE abundances with Galactic Chemical Evolution models computed using different sources of type Ia and type II supernova (SN Ia and SN II) yields. We find that a good fit to our observations can be obtained by assuming that a significant (~ 75%) fraction of SNe Ia stem from a sub-Chandrasekhar (sub-Ch) channel. While this fraction is larger than that found in earlier studies (~ 50%), we note that we still require ~ 25% near-Ch SNe Ia to obtain solar [Mn/Fe] at [Fe/H] = 0. Our new data also suggest higher SN II Mn yields at low metallicity than typically assumed in the literature.

[3]  arXiv:2003.01724 [pdf, ps, other]

Title: Ly$α$ Blobs from Cold Streams Undergoing Kelvin-Helmholtz Instabilities

Authors: Nir Mandelker, Frank C. van den Bosch, Daisuke Nagai, Avishai Dekel, Yuval Birnboim, Han Aung

Comments: 15 pages, 6 figures, submitted to MNRAS

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)

We present an analytic toy model for the radiation produced by the interaction between the cold streams thought to feed massive halos at high redshift and their hot CGM. We begin by deriving cosmologically motivated parameters for the streams as they enter the halo virial radius, $R_{\rm v}$, as a function of halo mass and redshift. For $10^{12}M_{\odot}$ halos at $z=2$, we find the Hydrogen number density in streams to be $n_{\rm H,s}\sim (0.1-5)\times 10^{-2}{\rm cm}^{-3}$, a factor of $\delta \sim (30-300)$ times denser than the hot CGM density, while the stream radii are in the range $R_{\rm s}\sim (0.03-0.50)R_{\rm v}$. As the streams accelerate towards the halo centre, they become denser and narrower. The stream-CGM interaction induces Kelvin-Helmholtz Instability (KHI), which leads to entrainment of CGM mass by the stream and therefore to stream deceleration by momentum conservation. Assuming that the entrainment rates derived by Mandelker et al. 2019 in the absence of gravity can be applied locally at each halocentric radius, we derive equations of motion for the stream in the halo. Using these, we derive the net acceleration, mass growth, and energy dissipation induced by the stream-CGM interaction, as a function of halo mass and redshift, for different CGM density profiles. For the range of model parameters considered, we find that the interaction can induce dissipation luminosities $L_{\rm diss}>10^{42}~{\rm erg~s^{-1}}$ within $\le 0.6 R_{\rm v}$ of halos with $M_{\rm v}>10^{12}M_{\odot}$ at $z=2$, with the emission scaling with halo mass and redshift approximately as $\propto M_{\rm v}\,(1+z)^2$. The magnitude and spatial extent of the emission produced in massive halos at high redshift is consistent with observed Ly$\alpha$ blobs, though better treatment of the UV background and self-shielding is needed to solidify this conclusion.

[4]  arXiv:2003.01725 [pdf, other]

Title: MOSEL Survey: Tracking the Growth of Massive Galaxies at 2<z<4 using Kinematics and the IllustrisTNG Simulation

Authors: Anshu Gupta, Kim-Vy Tran, Jonathan Cohn, Leo Y. Alcorn, Tiantian Yuan, Vicente Rodriguez-Gomez, Anishya Harshan, Ben Forrest, Lisa J. Kewley, Karl Glazebrook, Caroline M. Straatman, Glenn G. Kacprzak, Themiya Nanayakkara, Ivo Labbé, Casey Papovich, Michael Cowley

Comments: 19 pages, 9 figures, Accepted for publication in the Astrophysical Journal

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We use K-band spectroscopic data from the Multi-Object Spectroscopic Emission Line (MOSEL) survey to analyze the kinematic properties of galaxies at z>3. Our sample consists of 34 galaxies at 3.0<zspec<3.8 between 9.0<log(M_star)<11.0. We find that galaxies with log(M_star) > 10.2 at z > 3 have 56 +/- 21 km/s lower integrated velocity dispersion compared to galaxies at z ~ 2 of similar stellar mass. Massive galaxies at z > 3 have either a flat or declining star formation history (SFH), whereas similar stellar mass galaxies at z~2.0 exhibit a slight peak in the past 500 Myrs. Comparing with the IllustrisTNG cosmological simulation, we find that (i) the dynamical mass of massive galaxies in simulations (log(M_star) > 10.0) increases by ~0.1 dex at a fixed stellar mass between z=2.0-3.0, and (ii) dynamical mass growth is coupled with a rapid rise in the ex-situ stellar mass fraction (stars accreted from other galaxies) for massive galaxies at z < 3.5. We speculate that the rising contribution of ex-situ stellar mass to the total stellar mass growth of massive galaxies is driving the higher integrated velocity dispersion and rising SFHs of massive galaxies at z~2.0 compared to galaxies of similar stellar masses at z > 3.

[5]  arXiv:2003.01726 [pdf, ps, other]

Title: Strong surface outflows on accretion discs

Authors: C. J. Nixon, J. E. Pringle

Comments: 4 pages, 2 figures, accepted for publication in Astronomy & Astrophysics

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

In order to provide an explanation for the unexpected radial brightness distribution of the steady accretion discs seen in nova-like variables, Nixon & Pringle (2019) proposed that the accretion energy is redistributed outwards by means of strong, magnetically driven, surface flows. In this paper we note that the "powerful, rotating disc winds" observed in the soft states of black hole X-ray binaries, and also in the disc around a magnetized neutron star in Her X-1, have the properties of the outflows postulated by Nixon & Pringle to exist in the nova-like variable accretion discs around white dwarfs. The relevant properties are that the flows are not winds, but are, instead, bound flows (traveling at less than the escape velocity) and that the mass fluxes in the flows are a substantial fraction of the accretion rate in the disc.

[6]  arXiv:2003.01727 [pdf, other]

Title: S2COSMOS: Evolution of Gas Mass with Redshift Using Dust Emission

Authors: Jenifer S. Millard, Stephen A. Eales, M. W. L. Smith, H. L. Gomez, K. Małek, J. M. Simpson, Y. Peng, M. Sawicki, R. A. Beeston, Andrew Bunker, Y. Ao, A. Babul, L. C. Ho, Ho Seong Hwang, M. J. Michałowski, N. Scoville, H. Shim, Y. Toba

Comments: 17 pages (+ 9 pages of appendices), 8 figures (+ 7 figures in appendices), accepted for publication in MNRAS

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We investigate the evolution of the gas mass fraction for galaxies in the COSMOS field using submillimetre emission from dust at 850$\mu$m. We use stacking methodologies on the 850$\mu$m S2COSMOS map to derive the gas mass fraction of galaxies out to high redshifts, 0 <= $z$ <= 5, for galaxies with stellar masses of $10^{9.5} < M_* (\rm M_{\odot}) < 10^{11.75}$. In comparison to previous literature studies we extend to higher redshifts, include more normal star-forming galaxies (on the main sequence), and also investigate the evolution of the gas mass fraction split by star-forming and passive galaxy populations. We find our stacking results broadly agree with scaling relations in the literature. We find tentative evidence for a peak in the gas mass fraction of galaxies at around $z$ ~ 2.5-3, just before the peak of the star formation history of the Universe. We find that passive galaxies are particularly devoid of gas, compared to the star-forming population. We find that even at high redshifts, high stellar mass galaxies still contain significant amounts of gas.

[7]  arXiv:2003.01731 [pdf, other]

Title: The first dual-phase xenon TPC equipped with silicon photomultipliers and characterisation with $^{37}$Ar

Authors: L. Baudis, Y. Biondi, M. Galloway, F. Girard, S. Hochrein, S. Reichard, P. Sanchez-Lucas, K. Thieme, J. Wulf

Comments: 13 pages, 12 figures

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex); Nuclear Experiment (nucl-ex); Instrumentation and Detectors (physics.ins-det)

For the first time, a small dual-phase (liquid/gas) xenon time projection chamber was equipped with a top array of silicon photomultipliers for light and charge readout. Here we describe the instrument in detail, as well as the data processing and the event position reconstruction algorithms. We obtain a spatial resolution of ~1.5 mm in the horizontal plane. To characterise the detector performance, we show calibration data with internal $^{83\text{m}}$Kr and $^{37}$Ar sources, and we detail the production and introduction into the system of the latter. We finally compare the observed light and charge yields down to electronic recoil energies of 2.82 keV to predictions based on NEST v2.0.

[8]  arXiv:2003.01734 [pdf, other]

Title: SuperCLASS -- I. The Super CLuster Assisted Shear Survey: Project overview and Data Release 1

Authors: Richard A. Battye, Michael L. Brown, Caitlin M. Casey, Ian Harrison, Neal J. Jackson, Ian Smail, Robert A. Watson, Christopher A. Hales, Sinclaire M. Manning, Chao-Ling Hung, Christopher J. Riseley, Filipe B. Abdalla, Mark Birkinshaw, Constantinos Demetroullas, Scott Chapman, Robert J. Beswick, Tom W.B. Muxlow, Anna Bonaldi, Stefano Camera, Tom Hillier, Scott T. Kay, Aaron Peters, David B. Sanders, Daniel B. Thomas, A. P. Thomson, Ben Tunbridge, Lee Whittaker

Comments: 20 pages, 14 figures, 4 tables. Accepted in MNRAS. Links to Data Release catalogues will be updated when available upon publication. Before this, catalogues are available on request from the authors

Subjects: Astrophysics of Galaxies (astro-ph.GA)

The SuperCLuster Assisted Shear Survey (SuperCLASS) is a legacy programme using the e-MERLIN interferometric array. The aim is to observe the sky at L-band (1.4 GHz) to a r.m.s. of 7 uJy per beam over an area of ~1 square degree centred on the Abell 981 supercluster. The main scientific objectives of the project are: (i) to detect the effects of weak lensing in the radio in preparation for similar measurements with the Square Kilometre Array (SKA); (ii) an extinction free census of star formation and AGN activity out to z~1. In this paper we give an overview of the project including the science goals and multi-wavelength coverage before presenting the first data release. We have analysed around 400 hours of e-MERLIN data allowing us to create a Data Release 1 (DR1) mosaic of ~0.26 square degrees to the full depth. These observations have been supplemented with complementary radio observations from the Karl G. Jansky Very Large Array (VLA) and optical/near infra-red observations taken with the Subaru, Canada-France-Hawaii and Spitzer Telescopes. The main data product is a catalogue of 887 sources detected by the VLA, of which 395 are detected by e-MERLIN and 197 of these are resolved. We have investigated the size, flux and spectral index properties of these sources finding them compatible with previous studies. Preliminary photometric redshifts, and an assessment of galaxy shapes measured in the radio data, combined with a radio-optical cross-correlation technique probing cosmic shear in a supercluster environment, are presented in companion papers.

[9]  arXiv:2003.01735 [pdf, other]

Title: SuperCLASS -- II: Photometric Redshifts and Characteristics of Spatially-Resolved $μ$Jy Radio Sources

Authors: Sinclaire M. Manning, Caitlin M. Casey, Chao-Ling Hung, Richard Battye, Michael L. Brown, Neal Jackson, Filipe Abdalla, Scott Chapman, Constantinos Demetroullas, Patrick Drew, Christopher A. Hales, Ian Harrison, Christopher J. Riseley, David B. Sanders, Robert A. Watson

Comments: 14 pages, 13 figures, accepted for publication in MNRAS on March 3 2020

Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

We present optical and near-infrared imaging covering a $\sim$1.53 deg$^2$ region in the Super-Cluster Assisted Shear Survey (SuperCLASS) field, which aims to make the first robust weak lensing measurement at radio wavelengths. We derive photometric redshifts for $\approx$176,000 sources down to $i^\prime_{\rm AB}\sim24$ and present photometric redshifts for 1.4 GHz $e$-MERLIN and VLA detected radio sources found in the central 0.26 deg$^{2}$. We compile an initial catalog of 149 radio sources brighter than S$_{1.4}>75$ $\mu$Jy and find their photometric redshifts span $0<z_{\rm phot}<4$ with radio luminosities between $10^{21}-10^{25}$ W Hz$^{-1}$, with medians of $\langle z \rangle =0.55$ and $\langle L_{1.4}\rangle =1.9\times10^{23}$ W Hz$^{-1}$ respectively. We find 95% of the \uJy\ radio source sample (141/149) have SEDs best fit by star-forming templates while 5% (8/149) are better fit by AGN. Spectral indices are calculated for sources with radio observations from VLA and GMRT at 325 MHz, with an average spectral slope of $\alpha=0.59\pm0.04$. Using the full photometric redshift catalog we construct a density map at the redshift of the known galaxy clusters, $z=0.20\pm0.08$. Four of the five clusters are prominently detected at $>7 \sigma$ in the density map and we confirm the photometric redshifts are consistent with previously measured spectra from a few galaxies at the cluster centers.

[10]  arXiv:2003.01736 [pdf, other]

Title: SuperCLASS -- III. Weak lensing from radio and optical observations in Data Release 1

Authors: Ian Harrison, Michael L. Brown, Ben Tunbridge, Daniel B. Thomas, Tom Hillier, A. P. Thomson, Lee Whittaker, Filipe B. Abdalla, Richard A. Battye, Anna Bonaldi, Stefano Camera, Caitlin M. Casey, Constantinos Demetroullas, Christopher A. Hales, Neal J. Jackson, Scott T. Kay, Sinclaire M. Manning, Aaron Peters, Christopher J. Riseley, Robert A. Watson

Comments: 25 pages, 18 figures, 3 tables. Accepted in MNRAS

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

We describe the first results on weak gravitational lensing from the SuperCLASS survey: the first survey specifically designed to measure the weak lensing effect in radio-wavelength data, both alone and in cross-correlation with optical data. We analyse 1.53 square degrees of optical data from the Subaru telescope and 0.26 square degrees of radio data from the e-MERLIN and VLA telescopes (the DR1 data set). Using standard methodologies on the optical data only we make a significant (10 sigma) detection of the weak lensing signal (a shear power spectrum) due to the massive supercluster of galaxies in the targeted region. For the radio data we develop a new method to measure the shapes of galaxies from the interferometric data, and we construct a simulation pipeline to validate this method. We then apply this analysis to our radio observations, treating the e-MERLIN and VLA data independently. We achieve source densities of 0.5 per square arcmin in the VLA data and 0.06 per square arcmin in the e-MERLIN data, numbers which prove too small to allow a detection of a weak lensing signal in either the radio data alone or in cross-correlation with the optical data. Finally, we show preliminary results from a visibility-plane combination of the data from e-MERLIN and VLA which will be used for the forthcoming full SuperCLASS data release. This approach to data combination is expected to enhance both the number density of weak lensing sources available and the fidelity with which their shapes can be measured.

[11]  arXiv:2003.01737 [pdf, other]

Title: H$_2$ emission in the low-ionisation structures of the Planetary Nebulae NGC 7009 and NGC 6543

Authors: Stavros Akras, Denise R. Gonçalves, Gerardo Ramos-Larios, Isabel Aleman

Comments: 11 pages, 6 figures, 2 tables, accepted for Publication in MNRAS

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

Despite the many studies in the last decades, the low-ionisation structures (LISs) of planetary nebulae (PNe) still hold several mysteries. Recent imaging surveys have demonstrated that LISs are composed of molecular gas. Here we report H$_2$ emission in the LISs of NGC 7009 and NGC 6543 by means of very deep narrow-band H$_2$ images taken with NIRI@Gemini. The surface brightness of the H2 1-0 S(1) line is estimated to be (0.46-2.9)$\times$10$^{-4}$ erg s$^{-1}$ cm$^{-2}$ sr$^{-1}$ in NGC 7009 and (0.29-0.48)$\times$10$^{-4}$ erg s$^{-1}$ cm$^{-2}$ sr$^{-1}$ in NGC 6543, with signal-to-noise ratios of 10-42 and 3-4, respectively. These findings provide further confirmation of hidden H$_2$ gas in LISs. The emission is discussed in terms of the recent proposed diagnostic diagram R(H$_2$)=H$_2$ 1-0 S(1)/H$_2$ 2-1 S(1) versus R(Br$\gamma$)=H$_2$ 1-0 S(1)/Br$\gamma$, which was suggested to trace the mechanism responsible for the H$_2$ excitation. Comparing our observations to shock and ultraviolet (UV) molecular excitation models, as well as a number of observations compiled from the literature showed that we cannot conclude for either UV or shocks as the mechanism behind the molecular emission.

[12]  arXiv:2003.01738 [pdf, other]

Title: Physical models of streaming instabilities in protoplanetary disks

Authors: Jonathan Squire, Philip F. Hopkins

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

We develop simple, physically motivated models for drag-induced dust-gas streaming instabilities, which are thought to be crucial for clumping grains to form planetesimals in protoplanetary disks. The models explain, based on the physics of gaseous epicyclic motion and dust-gas drag forces, the most important features of the streaming instability and its simple generalisation, the disk settling instability. Some of the key properties explained by our models include the sudden change in the growth rate of the streaming instability when the dust-to-gas-mass ratio surpasses one, the slow growth rate of the streaming instability compared to the settling instability for smaller grains, and the main physical processes underlying the growth of the most unstable modes in different regimes. As well as providing helpful simplified pictures for understanding the operation of an interesting and fundamental astrophysical fluid instability, our models may prove useful for analysing simulations and developing nonlinear theories of planetesimal growth in disks.

[13]  arXiv:2003.01739 [pdf, other]

Title: Joint Radial Velocity and Direct Imaging Planet Yield Calculations: I. Self-consistent Planet Populations

Authors: Shannon D. Dulz, Peter Plavchan, Justin R. Crepp, Christopher Stark, Rhonda Morgan, Stephen R. Kane, Patrick Newman, William Matzko, Gijs D. Mulders

Comments: 22 pages, 17 figures, 5 tables, accepted to ApJ

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)

Planet yield calculations may be used to inform the target selection strategy and science operations of space observatories. Forthcoming and proposed NASA missions, such as the Wide-Field Infrared Survey Telescope (WFIRST), the Habitable Exoplanet Imaging Mission (HabEx), and the Large UV/Optical/IR Surveyor (LUVOIR), are expected to be equipped with sensitive coronagraphs and/or starshades. We are developing a suite of numerical simulations to quantify the extent to which ground-based radial velocity (RV) surveys could boost the detection efficiency of direct imaging missions. In this paper, we discuss the first step in the process of estimating planet yields: generating synthetic planetary systems consistent with observed occurrence rates from multiple detection methods. In an attempt to self-consistently populate stars with orbiting planets, it is found that naive extrapolation of occurrence rates (mass, semi-major axis) results in an unrealistically large number-density of Neptune-mass planets beyond the ice-line ($a \gtrsim 5$au), causing dynamic interactions that would destabilize orbits. We impose a stability criterion for multi-planet systems based on mutual Hill radii separation. Considering the influence of compact configurations containing Jovian-mass and Neptune-mass planets results in a marked suppression in the number of terrestrial planets that can exist at large radii. This result has a pronounced impact on planet yield calculations particularly in regions accessible to high-contrast imaging and microlensing. The dynamically compact configurations and occurrence rates that we develop may be incorporated as input into joint RV and direct imaging yield calculations to place meaningful limits on the number of detectable planets with future missions.

[14]  arXiv:2003.01760 [pdf, other]

Title: Stellar Mass and stellar Mass-to-light ratio-Color relations for Low Surface Brightness Galaxies

Authors: Du Wei, Cheng Cheng, Zheng Zheng, Wu Hong

Comments: Published in Astronomical Journal on March 3, 2020, see this https URL

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We estimate the stellar mass for a sample of low surface brightness galaxies (LSBGs) by fitting their multiband spectral energy distributions (SEDs) to the stellar population synthesis (SPS) model. The derived stellar masses (log M*/Msun) span from 7.1 to 11.1, with a mean of log M*/Msun=8.5, which is lower than that for normal galaxies. The stellar mass-to-light ratio (M/L) in each band varies little with absolute magnitude, but increases with higher M*. This trend of M/L with M* is even stronger in bluer bands. In addition, the M/L for our LSBGs slightly declines from the r band to the longer wavelength bands. The log M/L_j (j=g,r,i,and z) have relatively tight relations with optical colors of g-r and g-i. Compared with several representative M/L-color relations (MLCRs) from literature, our MLCRs based on LSBG data are consistently among those literature MLCRs previously defined on diverse galaxy samples, and the existing minor differences between the MLCRs are more caused by the differences in the SED model ingredients including initial mass function, star formation history, and stellar population model, and the line fitting techniques, galaxy samples, and photometric zero-point as well, rather than the galaxy surface brightness itself which distinguishes LSBGs from HSBGs. Our LSBGs would be very likely to follow those representative MLCRs previously defined on diverse galaxy populations, if those main ingredients were taken into account.

[15]  arXiv:2003.01778 [pdf, other]

Title: Evidence for Disk Truncation at Low Accretion States of the Black Hole Binary MAXI J1820+070 Observed by NuSTAR and XMM-Newton

Authors: Yanjun Xu, Fiona A. Harrison, John A. Tomsick, Jeremy Hare, Andrew C. Fabian, Dominic J. Walton

Comments: 8 pages, 5 figures, accepted for publication in ApJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We present results from NuSTAR and XMM-Newton observations of the new black hole X-ray binary MAXI J1820+070 at low accretion rates (below 1% of the Eddington luminosity). We detect a narrow Fe K$\alpha$ emission line, in contrast to the broad and asymmetric Fe K$\alpha$ line profiles commonly present in black hole binaries at high accretion rates. The narrow line, with weak relativistic broadening, indicates that the Fe K$\alpha$ line is produced at a large disk radius. Fitting with disk reflection models assuming standard disk emissivity finds a large disk truncation radius (a few tens to a few hundreds of gravitational radii, depending on the disk inclination). In addition, we detect a quasi-periodic oscillation (QPO) varying in frequency between $11.6\pm0.2$~mHz and $2.8\pm0.1$~mHz. The very low QPO frequencies suggest a large size for the optically-thin Comptonization region according to the Lense-Thirring precession model, supporting that the accretion disk recedes from the ISCO and is replaced by advection-dominated accretion flow at low accretion rates. We also discuss the possibility of an alternative accretion geometry that the narrow Fe K$\alpha$ line is produced by a lamppost corona with a large height illuminating the disk.

[16]  arXiv:2003.01780 [pdf, other]

Title: Chromosome maps of young LMC clusters: An additional case of coeval multiple populations

Authors: S. Saracino, S. Martocchia, N. Bastian, V. Kozhurina-Platais, W. Chantereau, M. Salaris, I. Cabrera-Ziri, E. Dalessandro, N. Kacharov, C. Lardo, S. S. Larsen, I. Platais

Comments: 12 pages, 7 figures, 1 table. Accepted for publication in MNRAS

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

Recent studies have revealed that the Multiple Populations (MPs) phenomenon does not occur only in ancient and massive Galactic globular clusters (GCs), but it is also observed in external galaxies, where GCs sample a wide age range with respect to the Milky Way. However, for a long time, it was unclear whether we were looking at the same phenomenon in different environments or not. The first evidence that the MPs phenomenon is the same regardless of cluster age and host galaxy came out recently when an intermediate-age cluster from the Small Magellanic Cloud, Lindsay 1, and a Galactic GC have been directly compared. By complementing those data with new images from the Hubble Space Telescope (HST), we extend the comparison to two clusters of different ages: NGC 2121 ($\sim$2.5Gyr) and NGC 1783 ($\sim$1.5Gyr), from the Large Magellanic Cloud. We find a clear correlation between the RGB width in the pseudo-colour $C_{F275W,F343N,F438W}$ and the age of the cluster itself, with the older cluster having larger $\sigma(C_{F275W,F343N,F438W})^{RGB}$ and vice-versa. Unfortunately, the $\sigma$ values cannot be directly linked to the N-abundance variations within the clusters before properly taking account the effect of the first dredge-up. Such HST data also allow us to explore whether multiple star-formation episodes occurred within NGC 2121. The two populations are indistinguishable, with an age difference of only 6$\pm$12 Myr and an initial Helium spread of 0.02 or lower. This confirms our previous results, putting serious constraints on any model proposed to explain the origin of the chemical anomalies in GCs.

[17]  arXiv:2003.01781 [pdf, ps, other]

Title: Formation of the polar debris disc around 99 Herculis

Authors: Jeremy L. Smallwood, Alessia Franchini, Cheng Chen, Eric Becerril, Stephen H. Lubow, Chao-Chin Yang, Rebecca G. Martin

Comments: 13 pages, 12 figures, accepted for publication in MNRAS

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

We investigate the formation mechanism for the observed nearly polar aligned (perpendicular to the binary orbital plane) debris ring around the eccentric orbit binary 99 Herculis. An initially inclined nonpolar debris ring or disc will not remain flat and will not evolve to a polar configuration, due to the effects of differential nodal precession that alter its flat structure. However, a gas disc with embedded well coupled solids around the eccentric binary may evolve to a polar configuration as a result of pressure forces that maintain the disc flatness and as a result of viscous dissipation that allows the disc to increase its tilt. Once the gas disc disperses, the debris disc is in a polar aligned state in which there is little precession. We use three-dimensional hydrodynamical simulations, linear theory, and particle dynamics to study the evolution of a misaligned circumbinary gas disc and explore the effects of the initial disc tilt, mass, and size. We find that for a wide range of parameter space, the polar alignment timescale is shorter than the lifetime of the gas disc. Using the observed level of alignment of 3 deg. from polar, we place an upper limit on the mass of the gas disc of about 0.014 M_sun at the time of gas dispersal. We conclude that the polar debris disc around 99 Her can be explained as the result of an initially moderately inclined gas disc with embedded solids. Such a disc may provide an environment for the formation of polar planets.

[18]  arXiv:2003.01785 [pdf, other]

Title: Assessment of astronomical images using combined machine learning models

Authors: Hossen Teimoorinia, J. J. Kavelaars, Stephen Gwyn, Daniel Durand, Kennedy Rolston, Alexander Ouellette

Comments: The Astronomical Journal accepted. 23 pages, 13 figures

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Astrophysics of Galaxies (astro-ph.GA)

We present a two-component Machine Learning (ML) based approach for classifying astronomical images by data-quality via an examination of sources detected in the images and image pixel values from representative sources within those images. The first component, which uses a clustering algorithm, creates a proper and small fraction of the image pixels to determine the quality of the observation. The representative images (and associated tables) are ~800 times smaller than the original images, significantly reducing the time required to train our algorithm. The useful information in the images is preserved, permitting them to be classified in different categories, but the required storage is reduced. The second component, which is a deep neural network model, classifies the representative images. Using ground-based telescope imaging data, we demonstrate that the method can be used to separate 'usable' images from those that present some problems for scientific projects -- such as images that were taken in sub-optimal conditions. This method uses two different data sets as input to a deep model and provides better performance than if we only used the images' pixel information. The method may be used in cases where large and complex data sets should be examined using deep models. Our automated classification approach achieves 97% agreement when compared to classification generated via manual image inspection. We compare our method with traditional results and show that the method improves the results by about 10%, and also presents more comprehensive outcomes.

[19]  arXiv:2003.01806 [pdf, other]

Title: The nature of a primary jet within a circumbinary disc outflow in a young stellar system

Authors: Chris J.R. Lynch, Michael D. Smith

Comments: 12 pages, 13 figures, submitted to MNRAS

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

Most stars form in binaries, and both stars may grow by accreting material from a circumbinary disc onto their personal discs. We suspect that in many cases a wide molecular wind will envelope a collimated atomic jet emanating from close to an orbiting young star. This so-called Circumbinary Scenario is explored here in order to find common identifiable properties. The dynamical set up is studied with three dimensional simulations with chemistry and cooling included. We extract the properties on scales of order 100\,AU and compare to the Co-Orbital Scenario in which the wind and jet sources are in orbit.
We find that the rapid orbital motion generates a wide ionised sheath around the jet core with a large opening angle at the base. This is independent of the presence of the surrounding molecular outflow. However, the atomic jet is recollimated beyond ~ 55 AU when the molecular outflow restricts the motion of the ambient medium which, in turn, confines the jet. These physical properties are relayed to the optical H-alpha imaging, providing a means of distinguishing between models. The high excitation sheath and recollimation region can be explored on these scales through the next generation of instruments. However, in general, the amount and location of the ionised material, whether in the knots or the sheath, will depend on several parameters including the orbital period, axis alignment and pulse amplitude.

[20]  arXiv:2003.01814 [pdf, other]

Title: ExoReL$^\Re$: A Bayesian Inverse Retrieval Framework For Exoplanetary Reflected Light Spectra

Authors: Mario Damiano, Renyu Hu

Comments: 20 pages, 16 figures, 6 tables, accepted for publication in AJ

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)

The high-contrast imaging technique is meant to provide insight into those planets orbiting several astronomical units from their host star. Space missions such as WFIRST, HabEx, and LUVOIR will measure reflected light spectra of cold gaseous and rocky planets.
To interpret these observations we introduce ExoReL$^\Re$ (Exoplanetary Reflected Light Retrieval), a novel Bayesian retrieval framework to retrieve cloud properties and atmospheric structures from exoplanetary reflected light spectra. As a unique feature, it assumes a vertically non-uniform volume mixing ratio profile of water and ammonia, and use it to construct cloud densities. In this way, clouds and molecular mixture ratios are consistent.
We apply ExoReL$^\Re$ on three test cases: two exoplanets ($\upsilon$ And e and 47 Uma b) and Jupiter. We show that we are able to retrieve the concentration of methane in the atmosphere, and estimate the position of clouds when the S/N of the spectrum is higher than 15, in line with previous works. Moreover, we described the ability of our model of giving a chemical identity to clouds, and we discussed whether or not we can observe this difference in the planetary reflection spectrum. Finally, we demonstrate how it could be possible to retrieve molecular concentrations (water and ammonia in this work) below the clouds by linking the non-uniform volume mixing ratio profile to the cloud presence. This will help to constrain the concentration of water and ammonia unseen in direct measurements.

[21]  arXiv:2003.01823 [pdf]

Title: A New Approach to Solar Flare Prediction

Authors: Michael L. Goodman (1), Chiman Kwan (2), Bulent Ayhan (2), Eric L. Shang (2) ((1) Jacobs Space Exploration Group, NASA Marshall Space Flight Center, Huntsville, AL, (2) Applied Research LLC, Rockville, MD)

Comments: 37 pages, 15 figures. Corresponding author - Michael L. Goodman. Accepted for publication 2/2020 by Frontiers of Physics

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

All three components of the current density are required to compute the heating rate due to free magnetic energy dissipation. Here we present a first test of a new model developed to determine if the times of increases in the resistive heating rate in active region (AR) photospheres are correlated with the subsequent occurrence of M and X flares in the corona. A data driven, 3 D, non-force-free magnetohydrodynamic model restricted to the near-photospheric region is used to compute time series of the complete current density and the resistive heating rate per unit volume $(Q(t))$ in each pixel in neutral line regions (NLRs) of 14 ARs. The model is driven by time series of the magnetic field ${\bf B}$ measured by the Helioseismic & Magnetic Imager on the Solar Dynamics Observatory (SDO) satellite. Spurious Doppler periods due to SDO orbital motion are filtered out of the time series for ${\bf B}$ in every AR pixel. For each AR, the cumulative distribution function (CDF) of the values of the NLR area integral $Q_i(t)$ of $Q(t)$ is found to be a scale invariant power law distribution essentially identical to the observed CDF for the total energy released in coronal flares. This suggests that coronal flares and the photospheric $Q_i$ are correlated, and powered by the same process. The model predicts spikes in $Q_i$ with values orders of magnitude above background values. These spikes are driven by spikes in the non-force free component of the current density. The times of these spikes are plausibly correlated with times of subsequent M or X flares a few hours to a few days later. The spikes occur on granulation scales, and may be signatures of heating in horizontal current sheets. It is also found that the times of relatively large values of the rate of change of the NLR unsigned magnetic flux are also plausibly correlated with the times of subsequent M and X flares, and spikes in $Q_i$.

[22]  arXiv:2003.01839 [pdf, other]

Title: Alfnoor: A Retrieval Simulation of the Ariel Target List

Authors: Quentin Changeat, Ahmed Al-Refaie, Lorenzo V. Mugnai, Billy Edwards, Ingo P. Waldmann, Enzo Pascale, Giovanna Tinetti

Comments: 26 pages, 18 figures

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)

In this work, we present Alfnoor, a dedicated tool optimised for population studies of exoplanet atmospheres. Alfnoor combines the latest version of the retrieval algorithm TauREx 3, with the instrument noise simulator ArielRad and enables the simultaneous retrieval analysis of a large sample of exo-atmospheres. We applied this tool to the Ariel list of planetary candidates and focus on hydrogen dominated, cloudy atmospheres observed in transit with the Tier-2 mode (medium Ariel resolution). As a first experiment, we randomised the abundances - ranging from 10$^{-7}$ to 10$^{-2}$ - of the trace gases, which include H$_2$O, CH$_4$, CO, CO$_2$ and NH$_3$. This exercise allowed to estimate the detection limits for Ariel Tier-2 and Tier-3 modes when clouds are present. In a second experiment, we imposed an arbitrary trend between a chemical species and the effective temperature of the planet. A last experiment was run requiring molecular abundances being dictated by equilibrium chemistry at a certain temperature. Our results demonstrate the ability of Ariel Tier-2 and Tier-3 surveys to reveal trends between the chemistry and associated planetary parameters. Future work will focus on eclipse data, on atmospheres heavier than hydrogen and will be applied also to other observatories.

[23]  arXiv:2003.01840 [pdf, other]

Title: Deciphering the 3-D Orion Nebula-I: Expanding Shells in the Huygens Region

Authors: C. R. O'Dell, N. P. Abel, G. J. Ferland

Subjects: Astrophysics of Galaxies (astro-ph.GA)

Based on imaging and spectroscopic data, we develop a 3-D model for the Huygens Region of the Orion Nebula. Theta1OriC , the hottest star in the Trapezium, is surrounded by a wind-blown Central Bubble that opens SW into the Extended Orion Nebula. Outside of this feature lies a layer of ionized gas at about 0.4 pc from Theta1OriC. Both of these features are moving rapidly away from Theta1OriC with an expansion age for the Central Bubble of only 15,000 yrs.

[24]  arXiv:2003.01845 [pdf, other]

Title: Molecule formation in dust-poor irradiated jets I. Stationary disk winds

Authors: B. Tabone, B. Godard, G. Pineau des Forêts, S. Cabrit, E. F. van Dishoeck

Comments: accepted for publication in A&A

Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

Recent ALMA observations suggest that the highest velocity part of molecular protostellar jets are launched from the dust-sublimation regions of the accretion disks (<0.3 au). However, formation and survival of molecules in inner protostellar disk winds, in the presence of a harsh FUV radiation field and the absence of dust, remain unexplored. We aim at determining if simple molecules can be synthesized and spared in fast and collimated dust-free disk winds or if a fraction of dust is necessary to explain the observed molecular abundances. This work is based on the Paris-Durham shock code designed to model irradiated environments. Fundamental properties of the dust-free chemistry are investigated from single point models. A laminar 1D disk wind model is then built using a parametric flow geometry. This model includes time-dependent chemistry and the attenuation of the radiation field by gas-phase photoprocesses. We show that a small fraction of H2 (< 1e-2), primarily formed through the H- route, can efficiently initiate molecule synthesis such as CO and SiO above TK ~ 800 K. The attenuation of the radiation field by atomic species (eg. C, Si, S) proceeds through continuum self-shielding. This process ensures efficient formation of CO, OH, SiO, H2O through neutral-neutral reactions, and the survival of these molecules. Class 0 dust-free winds with high mass-loss rates ($\dot{M}_w >$ 2e-6 Msun/yr) are predicted to be rich in molecules if warm (TK > 800 K). The molecular content of disk winds is very sensitive to the presence of dust and a mass-fraction of surviving dust as small as 1e-5 significantly increases the H2O and SiO abundances. Chemistry of high-velocity jets is a powerful tool to probe their content in dust and uncover their launching point. Models of internal shocks are required to fully exploit the current (sub-)millimeter observations and prepare future JWST observations.

[25]  arXiv:2003.01877 [pdf, ps, other]

Title: Quasi-periodic pulsation detected in Lyman-alpha emission during solar flares

Authors: Dong Li, Lei Lu, Zongjun Ning, Li Feng, Weiqun Gan, Hui Li

Comments: 21 pages, 7 figures, accepted for publication in The Astrophysical Journal

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

We investigated the quasi-periodic pulsation (QPP) in Lyman-alpha, X-ray and extreme-ultraviolet (EUV) emissions during two solar flares, i.e., an X-class (SOL2012-01-27T) and a C-class (SOL2016-02-08T). The full-disk Lyman-alpha and X-Ray flux during these solar flares were recorded by the EUV Sensor and X-Ray Sensor on board the Geostationary Operational Environmental Satellite. The {\deg}are regions were located from the EUV images measured by the Atmospheric Imaging Assembly. The QPP could be identified as a series of regular and periodic peaks in the light curves, and its quasi-periodicity was determined from the global wavelet and Fourier power spectra. A quasi-periodicity at about 3 minutes is detected during the impulsive phase of the X-class flare, which could be explained as the acoustic wave in the chromosphere (e.g., Milligan et al. 2017). Interestingly, a quasi-periodicity at roughly 1 minute is discovered during the entire evolutionary phases of solar flares, including the precursor, impulsive, and gradual phases. This is the first report of 1-minute QPP in the Lyman-alpha emission during solar flares, in particular during the flare precursor. It may be interpreted as a self-oscillatory regime of the magnetic reconnection, such as magnetic dripping.

[26]  arXiv:2003.01879 [pdf, ps, other]

Title: Kinetic simulations of nonrelativistic perpendicular shocks of young supernova remnants. III. Magnetic reconnection

Authors: Artem Bohdan, Martin Pohl, Jacek Niemiec, Sergei Vafin, Yosuke Matsumoto, Takanobu Amano, Masahiro Hoshino

Comments: 15 pages, 7 figures

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Plasma Physics (physics.plasm-ph)

Fully kinetic two-dimensional particle-in-cell simulations are used to study electron acceleration at high-Mach-number nonrelativistic perpendicular shocks. SNR shocks are mediated by the Weibel instability which is excited because of an interaction between shock-reflected and upstream ions. Nonlinear evolution of the Weibel instability leads to the formation of current sheets. At the turbulent shock ramp the current sheets decay through magnetic reconnection. The number of reconnection sites strongly depends on the ion-to-electron mass ratio and the Alfv\'enic Mach number of the simulated shock. Electron acceleration is observed at locations where magnetic reconnection operates. For the highest mass ratios almost all electrons are involved in magnetic reconnection, which makes the magnetic reconnection the dominant acceleration process for electrons at these shocks. We discuss the relevance of our results for 3D systems with realistic ion-to-electron mass ratio.

[27]  arXiv:2003.01882 [pdf, ps, other]

Title: Constraining the Neutrino Mass with the Drifting Coefficient of the Field Cluster Mass Function

Authors: Suho Ryu, Jounghun Lee (Seoul National University)

Comments: submitted for publication in ApJL, 7 figures

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

A new diagnostics to break the degeneracy between the total neutrino mass ($M_{\nu}$) and the primordial power spectrum amplitude ($\sigma_{8}$) by using the drifting coefficient of the field cluster mass function is presented. Analyzing the data from the Cosmological Massive Neutrino Simulations, we first determine the numerical mass functions of the field clusters at various redshifts. Then, we compare the numerical results with the analytical model characterized by a single parameter called the drifting coefficient which measures the drifts of the collapse density threshold, $\delta_{c}$, from the Einstein-de Sitter spherical value, $\delta_{sc}$, at a given mass scale. It is found that the analytic model for the field cluster mass function is found to work excellently even in the presence of massive neutrinos and that its drifting coefficient evolves differently in the cosmologies with different values of $M_{\nu}$. At low redshifts ($z\lesssim 0.3$) the more massive neutrinos drift $\delta_{c}$ further from $\delta_{sc}$, while the opposite trend is found at higher redshifts ($z\gtrsim0.3$). Claiming that this distinct redshift-dependent effect of massive neutrinos on the drifting coefficient of the field cluster mass function can help break the $\sigma_{8}$-$M_{\nu}$ degeneracy, we also show that the sensitivity of this new diagnostics to $M_{\nu}$ is high enough to discriminate the case of $M_{\nu}=0.1\,{\rm eV}$ from that of massless neutrinos.

[28]  arXiv:2003.01911 [pdf, other]

Title: Quasi-periodic Oscillation and Evidence of a Curved Jet in the Blazar 3C 454.3

Authors: Arkadipta Sarkar, Alok C. Gupta, Varsha R. Chitnis, Paul J. Wiita

Comments: 10 pages, 5 figures; Submitted to ApJL

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We report the detection of a quasi-periodic oscillation (QPO) in light curves of the blazar 3C 454.3. Periodic flux modulation was detected simultaneously in both $\gamma$--ray and optical wavebands with a dominant period of $\sim 47$ days. This period has a significance of over $4.2\sigma$ in the \textit{Fermi} $\gamma$--ray waveband and around $2.4\sigma$ in the optical V band. This QPO lasted for over 450 days (from MJD 56800 to 57250) resulting in over nine observed periods which is among the highest number of periods ever detected in a blazar light curve. The lower significance of the dominant period in optical wavebands is attributed to the absence of optical data for a number of QPO cycles due to the daytime transit of the source. We explore several physical models to explain the origin of this transient quasi-periodic modulation in the observed flux with a month-like period. These scenarios include a binary black hole system, a hotspot orbiting close to the innermost stable circular orbit of the supermassive black hole, and precessing jets. We conclude that the most likely scenario involves a region of enhanced emission moving helically inside a jet. Also, a curvature of $\sim 0.05^{\circ}$ pc$^{-1}$ in the jet fits the emission much better than does a straight blazar jet.

[29]  arXiv:2003.01919 [pdf, other]

Title: The rarity of repeating fast radio bursts from binary neutron star mergers

Authors: G. Q. Zhang, S. X. Yi, F. Y. Wang (NJU)

Comments: 7 pages, 2 figures, accepted for publication in ApJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

Fast radio bursts (FRBs) are extragalactic, bright pulses of emission at radio frequency with milliseconds duration. Observationally, FRBs can be divided into two classes, repeating FRBs and non-repeating FRBs. At present, twenty repeating FRBs have been discovered with unknown physical origins. Localization of the first repeating FRB 121102 and discovery of an associated persistent radio source support that FRBs are powered by young millisecond magnetars, which could be formed by core-collapses of massive stars or binary neutron stars mergers. These two formation channels can be distinguished by gravitational waves generated by binary neutron stars mergers. We first calculate the lower limit of the local formation rate of repeating FRBs observed by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) . Then we show that only a small fraction ($6\%$) of repeating FRBs is produced by young magnetars from binary neutron star mergers, basing on the gravitational wave detections by the third observing run (O3) of Advanced LIGO/Virgo gravitational-wave detectors. Therefore, we believe that repeating FRBs are more likely produced by the magnetars newborn from the core-collapses of massive stars rather than the magnetars from the binary neutron stars mergers.

[30]  arXiv:2003.01965 [pdf, other]

Title: Breaking Resonant Chains: Destabilization of Resonant Planets due to Long-term Mass Evolution

Authors: Yuji Matsumoto, Masahiro Ogihara

Comments: accepted for publication in The Astrophysical Journal

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

Recent exoplanet observations reported a large number of multiple-planet systems, in which some of the planets are in a chain of resonances. The fraction of resonant systems to non-resonant systems provides clues about their formation history. We investigated the orbital stability of planets in resonant chains by considering the long-term evolution of planetary mass and stellar mass and using orbital calculations. We found that while resonant chains were stable, they can be destabilized by a change of $\sim$10% in planetary mass. Such a mass evolution can occur by atmospheric escape due to photoevaporation. We also found that resonant chains can be broken by a stellar mass loss of $\lesssim1$%, which would be explained by stellar winds or coronal mass ejections. The long-term mass change of planets and stars plays an important role in the orbital evolutions of planetary systems including super-Earths.

[31]  arXiv:2003.01969 [pdf, other]

Title: The radio pulsar population of the Small Magellanic Cloud

Authors: N. Titus, S. Toonen, V.A. McBride, B.W. Stappers, D.A.H. Buckley, L. Levin

Comments: 10 pages, 4 figures

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)

We model the present day, observable, normal radio pulsar population of the Small Magellanic Cloud (SMC). The pulsars are generated with SeBa, a binary population synthesis code that evolves binaries and the constituent stellar objects up to remnant formation and beyond. We define radio pulsars by selecting neutron stars that satisfy a selection of criteria defined by Galactic pulsars, and apply the detection thresholds of previous and future SMC pulsar surveys.The number of synthesised and recovered pulsars are exceptionally sensitive to the assumed star formation history and applied radio luminosity model, but is not affected extensively by the assumed common envelope model, metallicity, and neutron star kick velocity distribution. We estimate that the SMC formed (1.6$\pm$0.3)$\times 10^4$ normal pulsars during the last 100 Myrs. We study which pulsars could have been observed by the Parkes multibeam survey of the SMC, by applying the survey's specific selection effects, and recover 4.0$\pm$0.8 synthetic pulsars.This is in agreement with their five observed pulsars. We also apply a proposed MeerKAT configuration for the upcoming SMC survey, and predict that the MeerKAT survey will detect 17.2$\pm$2.5 pulsars.

[32]  arXiv:2003.01992 [pdf, other]

Title: On the Impact of Satellite Constellations on Astronomical Observations with ESO telescopes in the Visible and Infrared Domains

Authors: Olivier R. Hainaut, Adrew P. Williams

Comments: 12 pages, 11 figures, 2 tables; accepted for publication in Astronomy and Astrophysics

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

The effect of satellite constellations on observations in the visible and IR domains is estimated, considering 18 constellations in development by SpaceX, Amazon, OneWeb, and others, with over 26,000 satellites, constituting a representative distribution. This study uses a series of simplifications and assumptions to obtain conservative, order-of-magnitude estimates of the effects.
The number of illuminated satellites from the constellations above the horizon ranges from ~1600 right after sunset, decreasing to 1100 at the end of astronomical twilight, most of them (~85%) close to the horizon (< 30deg). The large majority of these satellites will be too faint to be seen with the naked eye: at astronomical twilight, 110 brighter than mag 5. Most of them (~95%) will be close to the horizon. The number of naked-eye satellites plummets as the Sun reaches 30-40 deg below the horizon, depending on the latitude and season.
The light trails caused by satellites would ruin a small fraction (below the 1% level) of exposures using narrow to normal field imaging or spectroscopic techniques in the visible and near IR during the first and last hours of the night. Similarly, the thermal emission of the satellite would affect only a negligible fraction of thermal IR observations. However, wide-field exposures, as well as long medium-field exposures,would be affected at the 3% level during the first and last hours of the night. Furthermore, ultra-wide imaging exposures on a very large telescope (eg NSF's Rubin Observatory, LSST), would be significantly affected, with 30 to 40% of such exposures being compromised during the first and last hours of the night.
Coordination between the astronomical community, satellites companies, and government agencies is therefore critical to minimise and mitigate the effect on astronomical observations, in particular on survey telescopes.

[33]  arXiv:2003.01999 [pdf, ps, other]

Title: Gamma-ray and Optical properties of the flat spectrum radio quasar 3C 279 flare in June 2015

Authors: K K Singh, P J Meintjes, B Bisschoff, F A Ramamonjisoa, B van Soelen

Comments: 5 Figures, 7 Tables, Accepted for Publication in Journal of High Energy Astrophysics

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

The flat spectrum radio quasar 3C 279 was observed in an extremely high activity state on June 16, 2015 (MJD 57189). In this paper, we investigate the properties of this flaring episode in the high energy $\gamma$-ray and optical bands using data from the \emph{Fermi}-LAT, SMARTS, and SPOL observations during the period June 1-30, 2015 (MJD 57174-57203). The highest emission state in the $\gamma$-ray band detected by the \emph{Fermi}-LAT exhibits a peak flux of $\sim$ 2$\times$10$^{-7}$ erg~cm$^{-2}$~s$^{-1}$ which is more than 25 times the flux level measured in the low activity state of the source. The temporal analysis of the daily \emph{Fermi}-LAT light curve suggests that the giant flaring episode has characteristic rise and decay times less than one day. The optical daily light curves in B, V, R, and J bands also indicate the flaring activity from 3C 279 with flux levels peaking for two days on June 16-17, 2015 (MJD 57189-57190). The discrete correlation function analysis indicates a time lag of 1 day or longer between the $\gamma$-ray and optical peaks during the flaring episode. The $\gamma$-ray emission is also observed to show a harder-when-brighter behaviour whereas optical emission exhibits an opposite behaviour. The $\gamma$-ray emission region during the flare is observed to be very compact and is located close to the base of the jet. The degree of linear polarization in the wavelength range 500-700 nm measured using SPOL during this period is also highly variable with a peak of $\sim$ 30$\%$ one day after the $\gamma$-ray flare. Near simultaneous $\gamma$-ray flux points show a linear anti-correlation with the degree of polarization during the period of $\gamma$-ray flare. The significant drop in the degree of linear polarization suggests a sudden increase in the tangled magnetic field strength in the emission region.

[34]  arXiv:2003.02003 [pdf, other]

Title: The reconstruction of dark energy with Ridge Regression Approach

Authors: Long Huang, Xiaofeng Yang, Xiang Liu

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

It may be determined by non-parametric method if the dark energy evolves with time. We propose a method of combining PCA and biased estimation on the basis of ridge regression analysis to reconstruct parameters, meanwhile we present an interesting principal component selection criterion to avoid the arbitrariness of principal component selections, and use numerical integral by Lagrange interpolation to linearize the luminosity distance integral formula in nearly flat space to avoid instability of derivative for functional data. We get the preliminary test results that shows if $\Delta \overline w (z) = \overline {\left| {1 + w(z)} \right|} <=0.05$ included $w(z) = -1$, the probability of making a type I error for ${w_{recon}} \ne -1$ is almost zero ($1\% $) in the test; otherwise, if $\Delta \overline w (z) = \overline {\left| {1 + w(z)} \right|} > 0.05$, the probability of making a type I error for ${w_{recon}} = -1$ is not more than $10\% $. Finally, we use JLA sample to reconstruct $w(z)$, and the results reject ${\rm{w(z) }} \ne {\rm{ - 1}}$, which is agreement with $\Lambda CDM$ model.

[35]  arXiv:2003.02004 [pdf, ps, other]

Title: Magnetorotational Explosion of A Massive Star Supported by Neutrino Heating in General Relativistic Three Dimensional Simulations

Authors: Takami Kuroda, Almudena Arcones, Tomoya Takiwaki, Kei Kotake

Comments: 16 pages, 11 figures

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We present results of three-dimensional (3D), radiation-magnetohydrodynamics (MHD) simulations of core-collapse supernovae in full general relativity (GR), for the first time, with spectral neutrino transport. In order to study the effects of progenitor's rotation and magnetic fields on the dynamics and the emergent neutrino signals, we compute three models, where the precollapse rotation rate and magnetic fields are included parametrically to a 20 M$_{\odot}$ star. While we find no shock revival in our two non-magnetized models during our simulation times ($\sim500$ ms after bounce), the magnetorotationally driven shock expansion immediately initiates after bounce in our rapidly rotating and strongly magnetized model. We show that the expansion of the magnetorotationally-driven flows toward the polar directions is predominantly driven by the magnetic pressure, whereas the shock expansion toward the equatorial direction is supported by neutrino heating. After $\sim 150$ ms postbounce, the magnetorotationally-driven bipolar flows eventually cascades to an one-sided, unipolar flow. Our detailed analysis indicates that the growth of the so-called kink instability may hinder the collimation of jets, resulting in the formation of broader outflows. Furthermore we find a clear signature of the lepton-number emission self-sustained asymmetry (LESA), though only in the MR explosion model, whose asymmetry is consistent with the unipolar explosion morphology. We also report several unique neutrino signatures, which are significantly dependent on both the time and the viewing angle, if observed, possibly providing a rich information regarding the onset of the magnetorotationally-driven explosion.

[36]  arXiv:2003.02008 [pdf, other]

Title: Classical Nova Carinae 2018: Discovery of circumbinary iron and oxygen

Authors: Dominic McLoughlin, Katherine M. Blundell, Steven Lee

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We present time-lapse spectroscopy of a classical nova explosion commencing 9 days after discovery. These data reveal the appearance of a transient feature in Fe II and [O I]. We explore different models for this feature and conclude that it is best explained by a circumbinary disc shock-heated following the classical nova event. Circumbinary discs may play an important role in novae in accounting for the absorption systems known as THEA, the transfer of angular momentum, and the possible triggering of the nova event itself.

[37]  arXiv:2003.02029 [pdf, ps, other]

Title: IVOA HiPS Implementation in the Framework of WorldWide Telescope

Authors: Yunfei Xu, Chenzhou Cui, Dongwei Fan, Shanshan Li, Changhua Li, Jun Han, Linying Mi, Boliang He, Hanxi Yang, Yihan Tao, Sisi Yang, Lan He

Comments: 22 pages, 15 figures

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

The WorldWide Telescope(WWT) is a scientific visualization platform which can browse deep space images, star catalogs, and planetary remote sensing data from different observation facilities in a three-dimensional virtual scene. First launched and then open-sourced by Microsoft Research, the WWT is now managed by the American Astronomical Society (AAS). Hierarchical Progressive Survey (HiPS) is an astronomical data release scheme proposed by Centre de Donn\'ees astronomiques de Strasbourg (CDS) and has been accepted as a recommendation by International Virtual Observatory Alliance (IVOA). The HiPS solution has been adopted widely by many astronomical institutions for data release. Since WWT selected Hierarchical Triangular Mesh (HTM) as the standard for data visualization in the early stage of development, data released by HiPS cannot be visualized in WWT, which significantly limits the application of WWT. This paper introduces the implementation method for HiPS dataset visualization in WWT, and introduces HiPS data projection, mesh rendering, and data index implementation in WWT. Taking Chang'E-2 lunar probe data as an example, this paper introduces how to convert planetary remote sensing data into a HiPS dataset and integrate it into WWT. This paper also compares the efficiency and memory consumption of WWT loading its native data and HiPS data, and illustrates the application of HiPS in scientific data visualization and science education in WWT.

[38]  arXiv:2003.02032 [pdf, other]

Title: Kernel-phase analysis: aperture modeling prescriptions that minimize calibration errors

Authors: Frantz Martinache, Alban Ceau, Romain Laugier, Jens Kammerer, Mamadou N'Diaye, David Mary, Nick Cvetojevic, Coline Lopez

Comments: 12 pages, 15 figures, accepted for publication by Astronomy & Astrophysics

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

Kernel-phase is a data analysis method based on a generalization of the notion of closure-phase invented in the context of interferometry, but that applies to well corrected diffraction dominated images produced by an arbitrary aperture. The linear model upon which it relies theoretically leads to the formation of observable quantities robust against residual aberrations. In practice, detection limits reported thus far seem to be dominated by systematic errors induced by calibration biases not sufficiently filtered out by the kernel projection operator. This paper focuses on the impact the initial modeling of the aperture has on these errors and introduces a strategy to mitigate them, using a more accurate aperture transmission model. The paper first uses idealized monochromatic simulations of a non trivial aperture to illustrate the impact modeling choices have on calibration errors. It then applies the outlined prescription to two distinct data-sets of images whose analysis has previously been published. The use of a transmission model to describe the aperture results in a significant improvement over the previous type of analysis. The thus reprocessed data-sets generally lead to more accurate results, less affected by systematic errors. As kernel-phase observing programs are becoming more ambitious, accuracy in the aperture description is becoming paramount to avoid situations where contrast detection limits are dominated by systematic errors. Prescriptions outlined in this paper will benefit any attempt at exploiting kernel-phase for high-contrast detection.

[39]  arXiv:2003.02036 [pdf, other]

Title: Proxima Centauri b: A Strong Case for including Cosmic-Ray-induced Chemistry in Atmospheric Biosignature Studies

Authors: M. Scheucher, K. Herbst, V. Schmidt, J.L. Grenfell, F. Schreier, S. Banjac, B. Heber, H. Rauer, M. Sinnhuber

Comments: 10 pages, 5 figures. Accepted for publication in ApJ

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

Due to its Earth-like minimum mass of 1.27 M$_{\text{E}}$ and its close proximity to our Solar system, Proxima Centauri b is one of the most interesting exoplanets for habitability studies. Its host star, Proxima Centauri, is however a strongly flaring star, which is expected to provide a very hostile environment for potentially habitable planets. We perform a habitability study of Proxima Centauri b assuming an Earth-like atmosphere under high stellar particle bombardment, with a focus on spectral transmission features. We employ our extensive model suite calculating energy spectra of stellar particles, their journey through the planetary magnetosphere, ionosphere, and atmosphere, ultimately providing planetary climate and spectral characteristics, as outlined in Herbst et al. (2019). Our results suggest that together with the incident stellar energy flux, high particle influxes can lead to efficient heating of the planet well into temperate climates, by limiting CH$_4$ amounts, which would otherwise run into anti-greenhouse for such planets around M-stars. We identify some key spectral features relevant for future spectral observations: First, NO$_2$ becomes the major absorber in the visible, which greatly impacts the Rayleigh slope. Second, H$_2$O features can be masked by CH$_4$ (near infra-red) and CO$_2$ (mid to far infra-red), making them non-detectable in transmission. Third, O$_3$ is destroyed and instead HNO$_3$ features become clearly visible in the mid to far infra-red. Lastly, assuming a few percent of CO$_2$ in the atmosphere, CO$_2$ absorption at 5.3 $\mu$m becomes significant (for flare and non-flare cases), strongly overlapping with a flare related NO feature in Earth's atmosphere.

[40]  arXiv:2003.02045 [pdf, ps, other]

Title: Leptonic or Hadronic Emission: X-Ray Radiation Mechanism of Large-scale Jet Knots in 3C 273

Authors: Zhen-Jie Wang (GXU), Jin Zhang (NAOC), Xiao-Na Sun (NJU), En-Wei Liang (GXU)

Comments: 24 pages, 8 figures, 3 tables, accepted for publication in ApJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

A comprehensively theoretical analysis on the broadband spectral energy distributions (SEDs) of large-scale jet knots in 3C 273 is presented for revealing their X-ray radiation mechanism. We show that these SEDs cannot be explained with a single electron population model when the Doppler boosting effect is either considered or not. By adding a more energetic electron (the leptonic model) or proton (the hadronic model) population, the SEDs of all knots are well represented. In the leptonic model, the electron population that contributes the X-ray emission is more energetic than the one responsible for the radio-optical emission by almost two orders of magnitude; the derived equipartition magnetic field strengths (B_eq) are ~0.1 mG. In the hadronic model, the protons with energy of ~20 PeV are required to interpret the observed X-rays; the B_eq values are several mG, larger than that in the leptonic model. Based on the fact that no resolved substructures are observed in these knots and the fast cooling-time of the high-energy electrons is difficult to explain the observed X-ray morphologies, we argue that two distinct electron populations accelerated in these knots are unreasonable and their X-ray emission would be attributed to the proton synchrotron radiation accelerated in these knots. In case of these knots have relativistic motion towards the observer, the super-Eddington issue of the hadronic model could be avoided. Multiwavelength polarimetry and the gamma-ray observations with high resolution may be helpful to discriminate these models.

[41]  arXiv:2003.02056 [pdf, other]

Title: Three-dimensional simulations of accretion flow in the progenitor of Tycho's supernova

Authors: Li Xue, Cheng-Liang Jiao, Yuan Li

Comments: 9 pages, 13 figures, submitted to MNRAS

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)

We run three-dimensional numerical simulations for the accretion flow around the white dwarf (WD) in the progenitor system of Tycho's supernova (SN). The mass of the WD, mass of the companion star, and the orbital period are set to be 1$M_{\odot}$, 1.6$M_{\odot}$, and 0.794 day, respectively, based on theoretical and observational researches of Tycho's SN remnant (SNR). We find that when the magnetic field in the accreted material is negligible, outflowing wind is concentrated near the equatorial plane. When the magnetic field has energy equipartition with internal energy, polar wind is comparable with the equatorial wind. A carefully chosen magnetic field between the above two cases ($B=5.44\times10^3 \rm{G}$) can roughly reproduce the latitude-dependent wind required to form the peculiar periphery of Tycho's SNR.

[42]  arXiv:2003.02061 [pdf, other]

Title: A Three Dimensional View of Gomez's Hamburger

Authors: Richard Teague, Marija R. Jankovic, Thomas J. Haworth, Chunhua Qi, John D. Ilee

Comments: Submitted to MNRAS

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

Unraveling the 3D physical structure, the temperature and density distribution, of protoplanetary discs is an essential step if we are to confront simulations of embedded planets or dynamical instabilities. In this paper we focus on Submillimeter Array observations of the edge-on source, Gomez's Hamburger, believed to host an over-density hypothesised to be a product of gravitational instability in the disc, GoHam b. We demonstrate that, by leveraging the well characterised rotation of a Keplerian disc to deproject observations of molecular lines in position-position-velocity space into disc-centric coordinates, we are able to map out the emission distribution in the (r, z) plane and (x, y, z) space. We show that 12CO traces an elevated layer of $z\,/\,r \sim 0.3$, while 13CO traces deeper in the disc at $z\,/\,r \lesssim 0.2$. We localize emission associated with GoHam b, finding it at deprojected radius of approximately 500 au and at polar angle of +\- 30 degrees from the disc major axis. At the spatial resolution of $\sim 1.5^{\prime\prime}$, GoHam b is spatially unresolved, with an upper limit to its radius of $<190$~au.

[43]  arXiv:2003.02066 [pdf, other]

Title: Bounce from Inflation

Authors: Debottam Nandi

Comments: 5 pages, 5 figures

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

We construct a class of viable bouncing models that are conformally related to cosmological inflation. There are three main difficulties in constructing such a model: (i) A stable (attractor) solution, (ii) A non-singular bounce, and (iii) to bypass the no-go theorem that states that simultaneously maintaining the observational bounds on the tensor-to-scalar ratio and the non-Gaussian scalar spectrum are not possible. We show that a non-minimal coupling of the scalar field helps to bypass these difficulties and provides viable bouncing models. We also obtain a naturally occurring reheating epoch briefly after the bouncing phase.

[44]  arXiv:2003.02069 [pdf, ps, other]

Title: A surprise in the updated list of stellar perturbers of long period comets motion

Authors: Rita Wysoczańska, Piotr A. Dybczyński, Magdalena Polińska

Comments: 10 pages, 3 figures, submitted to Astronomy and Astrophysics

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

The second Gaia data release (Gaia DR2) provided us with precise five-parameter astrometry for 1.3 billion of sources. As stars passing close to the Solar System are thought to be responsible for influencing the dynamical history of long period comets, thanks to the increase of an amount of data, we were able to study, with a better accuracy, the sample of stellar perturbers of a cometary motion. We aim to add new objects to a list of stellar perturbers of long period comets motion and to revise previously published lists. Special emphasis was placed on stellar systems as multiplicity of the stars was almost never considered in this context before. Discussion on sources of masses and perturber mass estimates are included. Using right ascensions, declinations, parallaxes, proper motions, and radial velocities, preferably all from Gaia DR2, augmented with data from other sources when needed, we calculate spatial positions and velocities for each star. To obtain minimal heliocentric distances we numerically integrate motion of stars under the Galactic potential and their mutual interactions. We present the updated list of stellar perturbers of cometary motion, including masses of perturbers, ready to be used with data on the observed long period comets to study an individual influence of a whole sample of perturbers, or specific stars, on a dynamical past or future of a specific comet. 147 new perturbers were added in comparison to the previously published sources. Data provided by Gaia DR2 facilitated an extension of the list of stellar perturbers with new objects and a verification of these which were earlier classified as the pertubers of cometary motion. However, lack of radial velocities for millions of stars still hinders our work. Almost no improvement is visible in a multiple systems field, they have to be treated with extra diligence.

[45]  arXiv:2003.02075 [pdf, other]

Title: An analytical approximation of the scalar spectrum in the ultra-slow-roll inflationary models

Authors: Jing Liu, Zong-Kuan Guo, Rong-Gen Cai

Comments: 7 pages, 3 figures

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)

The ultra-slow-roll (USR) inflationary models predict large-amplitude scalar perturbations at small scales which can lead to the primordial black hole production and scalar-induced gravitational waves. In general scalar perturbations in the USR models can only be obtained using numerical method because the usual slow-roll approximation breaks. In this work, we propose an analytical approach to estimate the scalar spectrum which is consistent with the numerical result. We find that the USR inflationary models predict a peak with power-law slopes in the scalar spectrum and energy spectrum of gravitational waves, and we derive the expression of the spectral indexes in terms of the inflationary potential. In turn, the inflationary potential near the USR regime can be reconstructed from the negative spectral index of the gravitational wave energy spectrum.

[46]  arXiv:2003.02094 [pdf, ps, other]

Title: Stellar wind models of central stars of planetary nebulae

Authors: J. Krticka, J. Kubat, I. Krtickova

Comments: 14 pages, accepted for publication in Astronomy & Astrophysics

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

Fast line-driven stellar winds play an important role in the evolution of planetary nebulae. We provide global hot star wind models of central stars of planetary nebulae. The models predict wind structure including the mass-loss rates, terminal velocities, and emergent fluxes from basic stellar parameters. We applied our wind code for parameters corresponding to evolutionary stages between the asymptotic giant branch and white dwarf phases. We study the influence of metallicity and wind inhomogeneities (clumping) on the wind properties. Line-driven winds appear very early after the star leaves the asymptotic giant branch (at the latest for $T_\rm{eff}\approx10\,$kK) and fade away at the white dwarf cooling track (below $T_\rm{eff}=105\,$kK). Their mass-loss rate mostly scales with the stellar luminosity and, consequently, the mass-loss rate only varies slightly during the transition from the red to the blue part of the Hertzsprung-Russell diagram. There are the following two exceptions to the monotonic behavior: a bistability jump at around $20\,$kK, where the mass-loss rate decreases by a factor of a few (during evolution) due to a change in iron ionization, and an additional maximum at about $T_\rm{eff}=40-50\,$kK. On the other hand, the terminal velocity increases from about a few hundreds of $\rm{km}\,\rm{s}^{-1}$ to a few thousands of $\rm{km}\,\rm{s}^{-1}$ during the transition as a result of stellar radius decrease. The wind terminal velocity also significantly increases at the bistability jump. Derived wind parameters reasonably agree with observations. The effect of clumping is stronger at the hot side of the bistability jump than at the cool side. Derived fits to wind parameters can be used in evolutionary models and in studies of planetary nebula formation. A predicted bistability jump in mass-loss rates can cause the appearance of an additional shell of planetary nebula.

[47]  arXiv:2003.02101 [pdf, other]

Title: Benzonitrile as a proxy for benzene in the cold ISM: low temperature rate coefficients for CN + C$_6$H$_6$

Authors: Ilsa R. Cooke, Divita Gupta, Joseph P. Messinger, Ian R. Sims

Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

The low temperature reaction between CN and benzene (C$_6$H$_6$) is of significant interest in the astrochemical community due to the recent detection of benzonitrile, the first aromatic molecule identified in the interstellar medium (ISM) using radio astronomy. Benzonitrile is suggested to be a low temperature proxy for benzene, one of the simplest aromatic molecules, which may be a precursor to polycyclic aromatic hydrocarbons (PAHs). In order to assess the robustness of benzonitrile as a proxy for benzene, low temperature kinetics measurements are required to confirm whether the reaction remains rapid at the low gas temperatures found in cold dense clouds. Here, we study the C$_6$H$_6$ + CN reaction in the temperature range 15--295 K, using the well-established CRESU technique (a French acronym standing for Reaction Kinetics in Uniform Supersonic Flow) combined with Pulsed Laser Photolysis-Laser-Induced Fluorescence (PLP-LIF). We obtain rate coefficients, $k(T)$, in the range (3.6--5.4) $\times$ 10$^{-10}$ cm$^3$ s$^{-1}$ with no obvious temperature dependence between 15--295 K, confirming that the CN + C$_6$H$_6$ reaction remains rapid at temperatures relevant to the cold ISM.

[48]  arXiv:2003.02145 [pdf, other]

Title: Original use of MUSE's laser tomography adaptive optics to directly image young accreting exoplanets

Authors: Julien H. Girard, Jozua de Boer, Sebastiaan Haffert, Peter Zeidler, Alexander Bohn, Rob G. van Holstein, Ignas Snellen, Jarle Brinchmann, Christoph Keller, Roland Bacon, Jaehan Bae

Comments: AO4ELT6 Conference Proceedings (2019), 12 pages, 6 figures (this http URL)

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

We present recent results obtained with the VLT/MUSE Integral Field Spectrograph fed by the 4LGSF and its laser tomography adaptive optics module GALACSI. While this so-called narrow-field mode of MUSE was not designed to perform directly imaging of exoplanets and outflows, we show that it can be a game changer to detect and characterize young exoplanets with a prominent emission lines (i.e H{\alpha}, tracer of accretion), at moderate contrasts. These performances are achieved thanks to the combo of a near-diffraction limited PSF and a medium resolution spectrograph and a cross-correlation approach in post-processing . We discuss this in the context of ground and space, infrared and visible wavelengths, preparing for missions like JWST and WFIRST in great synergy and as pathfinder for future ELT/GSMT (Extremely Large and/or Giant Segmented Mirror Telescopes) instruments.

[49]  arXiv:2003.02146 [pdf, other]

Title: The Variability of Star Formation Rate in Galaxies: II. Power Spectrum Distribution on the Main Sequence

Authors: Enci Wang, Simon J. Lilly

Comments: 22 pages, 13 figures, submitted to AAS

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We constrain the temporal power spectrum of the sSFR(t) of star-forming galaxies, using a well-defined sample of Main Sequence galaxies from MaNGA and our earlier measurements of the ratio of the SFR averaged within the last 5 Myr to that averaged over the last 800 Myr. We explore the assumptions of stationarity and ergodicity that are implicit in this approach. We assume a single power-law form of the PSD but introduce an additional free parameter, the "intrinsic scatter", to try to account for any non-ergodicity introduced from various sources. We analyze both an "integrated" sample consisting of global measurements of all of the galaxies, and also 25 sub-samples obtained by considering five radial regions and five bins of integrated stellar mass. Assuming that any intrinsic scatter is not the dominant contribution to the Main Sequence dispersion of galaxies, we find that the PSDs have slopes between 1.0 and 2.0, indicating that the power (per log interval of frequency) is mostly contributed by longer timescale variations. We find a correlation between the returned PSDs and the inferred gas depletion times ($\tau_{\rm dep,eff}$) obtained from application of the extended Schmidt Law, in that regions with shorter gas depletion times show larger integrated power and flatter PSD. Intriguingly, it is found that shifting the PSDs by the inferred $\tau_{\rm dep,eff}$ causes all of the 25 PSDs to closely overlap, at least in that region where the PSD is best constrained and least affected by uncertainties about any intrinsic scatter. A possible explanation of these results is the dynamical response of the gas regulator system of Lilly et al. 2013 to a uniform time-varying inflow, as previously proposed in Wang et al. 2019.

[50]  arXiv:2003.02152 [pdf, other]

Title: Improved neutrino-nucleon interactions in dense and hot matter for numerical simulations

Authors: Micaela Oertel (LUTH (UMR\_8102)), Aurélien Pascal (LUTH (UMR\_8102)), Marco Mancini, Jerome Novak (LUTH (UMR\_8102))

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)

Neutrinos play an important role in compact star astrophysics: neutrino-heating is one of the main ingredients in core-collapse supernovae, neutrino-matter interactions determine the composition of matter in binary neutron star mergers and have among others a strong impact on conditions for heavy element nucleosynthesis and neutron star cooling is dominated by neutrino emission except for very old stars. Many works in the last decades have shown that in dense matter medium effects considerably change the neutrino-matter interaction rates, whereas many astrophysical simulations use analytic approximations which are often far from reproducing more complete calculations. In this work we present a scheme which allows to incorporate improved rates, for charged current interactions, into simulations and show as an example some results for core-collapse supernovae, where a noticeable difference is found in the location of the neutrinospheres of the low-energy neutrinos in the early post-bounce phase.

[51]  arXiv:2003.02162 [pdf]

Title: Why radio quiet quasars are preferred over radio loud quasars regardless of environment and redshift

Authors: David Garofalo, Max North, Leanne Belga, Kenzi Waddell

Journal-ref: The Astrophysical Journal 2020

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

Evidence has accumulated suggesting the clustering of radio loud quasars is greater than for radio quiet quasars. We interpret these results in a context in which the fraction of radio loud quasar formation is less than or equal to that for radio quiet quasars for all environments and redshift. Because we assume that post-merger cold gas onto large black holes produces either a radio loud or a radio quiet quasar, we show that for largest black hole masses that live in largest dark matter halos, fRLQ approaches 0.5 from below but does not exceed it, such that in rich clusters the formation of a radio loud quasar tends to be equally likely to occur as a radio quiet quasar. In dark matter halos with smaller mass, by contrast, radio quiet quasars are more likely to form and the likelihood increases inversely with dark matter halo mass. As a result, averaging over a population of radio loud and radio quiet quasars will necessarily generate lower average black hole masses for the radio quiet subgroup. Hence, despite the fact that the formation of radio quiet quasars is preferred over radio loud quasars in any environment, at any mass scale, at any luminosity, or redshift, averaging over a range of radio loud quasars will give the appearance they are preferred in cluster environments over radio quiet quasars. We show how this also accounts for the order of magnitude difference in the total number of jetted active galaxies compared to non-jetted counterparts.

[52]  arXiv:2003.02163 [pdf]

Title: Spin of the M87 black hole

Authors: David Garofalo

Journal-ref: Annalen der Physik 2020

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

Spin measurement of the 6.5 billion solar mass black hole in M87 from the Event Horizon Telescope image is the latest in a series that span a wide range in values, but that tend to share the feature of co-rotation between the accretion flow and black hole. The spin paradigm for black holes predicts very high black hole spin which in that framework was produced in its last significant merger. High black hole spin appears to be ruled out in the gap paradigm, however, which predicts early formation with a mass already in excess of 4 billion solar masses. In this picture, the black hole experienced slow evolution as it departed from its original radio quasar phase and over billions of years not only failed to double its mass but also fell short of regaining its original high spin, such that it is now compatible with a co-rotating accreting black hole whose dimensionless spin fits best in the range 0.2 < a < 0.5.

[53]  arXiv:2003.02184 [pdf]

Title: First year of coordinated science observations by Mars Express and ExoMars 2016 Trace Gas Orbiter

Authors: A. Cardesin-Moinelo, B. Geiger, G. Lacombe, B. Ristic, M. Costa, D. Titov, H. Svedhem, J. Marin-Yaseli, D. Merritt, P. Martin, M.A. Lopez-Valverde

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

In this paper we describe the first combined observations executed by the Mars Express and Trace Gas Orbiter missions since the start of the TGO operational phase in April 2018 until June 2019. Also included is the science opportunity analysis that has been performed by the Science Operation Centres and instrument teams to identify the observation opportunities until the end of 2020. These results provide a valuable contribution to the scientific community by enabling collaborations within the instrument teams and enhance the scientific outcome of both missions. This information is also valuable to other Mars missions, which may be interested in observing these locations for wider scientific collaboration.

[54]  arXiv:2003.02211 [pdf, other]

Title: Combined Analysis of X-Ray Spectra of NGC 3227

Authors: J. Newman, S. Tsuruta, A. C. Liebmann, H. Kunieda, Y. Haba

Comments: 29 pages, 5 tables, and 11 figures

Subjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)

The 1.5 Seyfert galaxy NGC 3227 has been observed by several X-ray missions. We carried out combined analysis of the data obtained by more recent major observations of this source - two observations performed by XMM-Newton in 2000 and 2006 and six observations performed by Suzaku in 2008.
A unified model was constructed which is consistent with all eight of the observations by the two satellites with large intensity and spectral changes. The model consists of a hard power law with the spectral index of 1.35-1.65 which is interpreted as the Comptonized emission from the corona above an accretion disk. In the high flux states an additional soft excess component dominates, which is consistent with a model with either a steeper power law with an index of 3.5-3.6 or the warm Comptonization component. These emissions from the central engine are absorbed by a neutral partial covering material and warm absorbers. A reflection component and several emission lines are also present. We examined the relationship between the intrinsic luminosity and the absorbers' physical parameters such as the column density, which suggests that the source expanded significantly during the bright states where the soft excess is greatly enhanced.

[55]  arXiv:2003.02242 [pdf, other]

Title: The disappearance of a massive star in the low metallicity galaxy PHL 293B

Authors: Andrew Allan, Jose Groh, Andrea Mehner, Nathan Smith, Ioana Boian, Eoin Farrell

Comments: 4, pages, 5 figures, submitted to A&A Letters

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)

Our current understanding of the final stages of massive star evolution is largely incomplete, particularly in low metallicity environments. To improve upon this, we investigate the behavior of a suspected LBV in one of the most metal-poor dwarf galaxies, PHL 293B. Excitingly, we find the sudden disappearance of the LBV signature from our spectra obtained in 2019. Spectroscopic observations of PHL 293B between 2001 and 2009 consistently revealed both narrow and broad strong emission components in the hydrogen Balmer lines, with minimal variation between observations. These broad components combined with P Cygni profiles have been associated with a massive Luminous Blue Variable (LBV) star. However, such features are absent from our spectra obtained in 2019 with the ESPRESSO and X-shooter instruments of the ESO's VLT, as well as archival data from 2011 and 2016. We compute radiative transfer models using CMFGEN that fit the observed spectrum of the LBV. This reveals that during 2001-2009 the LBV had a luminosity $L_* = 2.5-5.0 \times 10^6 L_{\odot}$, a mass-loss rate $\dot{M} = 0.005-0.020 M_{\odot}$ yr$^{-1}$, a stellar wind velocity of 1000 km s$^{-1}$, and an effective temperature $T_\mathrm{eff} = 6000-6800$ K. These values indicate an eruptive state. We consider two main hypotheses for the absence of the broad emission components from the spectra obtained since 2011. One possibility is that we are seeing the end of an LBV eruption of a surviving star, with a mild drop in luminosity, a shift to hotter effective temperatures, and some dust obscuration. Alternatively, the LBV could have collapsed to a massive black hole without the production of a bright supernova.

Cross-lists for Thu, 5 Mar 20

[56]  arXiv:2001.01706 (cross-list from hep-ph) [pdf, ps, other]

Title: Vacuum energy with mass generation and Higgs bosons

Authors: Steven D. Bass, Janina Krzysiak

Comments: 4 pages, to appear in Physics Letters B

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)

We discuss the Higgs mass and cosmological constant hierarchy puzzles with emphasis on the interplay of Poincare invariance, mass generation and renormalization group invariance. A plausible explanation involves an emergent Standard Model with the cosmological constant scale suppressed by power of the large scale of emergence. In this scenario the cosmological constant scale and neutrino masses should be of similar size.

[57]  arXiv:2003.01333 (cross-list from gr-qc) [pdf, other]

Title: Schwarzschild Metric with Planck Length

Authors: Michael R.R. Good, Eric V. Linder

Comments: 14 pages, 9 figures

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE)

We present a modified Schwarzschild solution for a model of evaporation of a black hole with information preservation. By drawing a direct analogy to the quantum pure accelerating mirror (dynamical Casimir effect of a 1D horizon), we derive a Schwarzschild metric with not only the usual Schwarzschild radius but an additional length scale related to the Planck length. The black hole has thermal particle production that leads to complete evaporation of the black hole, resulting in non-divergent entanglement entropy, Page curve turn-over, and an asymptotic quantum pure state with no information loss.

[58]  arXiv:2003.01441 (cross-list from gr-qc) [pdf, other]

Title: Full analytical formulas for frequency response of space-based gravitational wave detectors

Authors: Chunyu Zhang, Qing Gao, Yungui Gong, Bin Wang, Alan J. Weinstein, Chao Zhang

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

The discovery of gravitational waves which are ripples of the space-time itself opened a new window to test general relativity because it predicts that there are only plus and cross polarizations for gravitational waves. For alternative theories of gravity, there may have up to six polarizations. The measurement of the polarization is one of the major scientific goals for the future gravitational wave detectors. To evaluate the capability of the detector, we need to use the frequency dependent response functions averaged over the source direction and polarization angle. We derive the full analytical formulas of the averaged response functions for all six possible polarizations and present their asymptotic behaviors based on these analytical formulas. Compared with the numerical simulation, the full analytical formulas are much efficient and are valid for any equal-arm interferometric gravitational wave detectors without optical cavities in the arms and for time-delay-interferometry Michelson combination.

[59]  arXiv:2003.01617 (cross-list from gr-qc) [pdf, other]

Title: How attractive is the isotropic attractor solution of axion-SU(2) inflation?

Authors: Ira Wolfson, Azadeh Maleknejad, Eiichiro Komatsu

Comments: 19 pages, 7 figures

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

The key to the phenomenological success of inflation models with axion and SU(2) gauge fields is the isotropic background of the SU(2) field. Previous studies showed that this isotropic background is an attractor solution during inflation starting from anisotropic (Bianchi Type I) spacetime; however, not all possible initial anisotropic parameter space was explored. In this paper, we explore more generic initial conditions without assuming the initial slow-roll dynamics. We find some initial anisotropic parameter space which does not lead to the isotropic background, but to violation of slow-roll conditions, terminating inflation prematurely. The basin of attraction increases when we introduce another scalar field acting as inflaton and make the axion-SU(2) system a spectator sector. Therefore, the spectator axion-SU(2) model is phenomenologically more attractive.

[60]  arXiv:2003.01717 (cross-list from physics.plasm-ph) [pdf, other]

Title: Electronic parametric instabilities of an ultrarelativistic laser pulse in a plasma

Authors: Ferdinand Gleixner, Naveen Kumar

Journal-ref: Phys. Rev. E 101, 033201 (2020)

Subjects: Plasma Physics (physics.plasm-ph); High Energy Astrophysical Phenomena (astro-ph.HE)

Electronic parametric instabilities of an ultrarelativistic circularly polarized laser pulse propagating in underdense plasmas are studied by numerically solving the dispersion relation which includes the effect of the radiation reaction force in laser-driven plasma dynamics. Emphasis is placed on studying the different modes in the laser-plasma system and identifying the absolute and convective nature of the unstable modes in a parameter map spanned by the normalized laser vector potential and the plasma density. Implications for the ultraintense laser-plasma experiments are pointed out.

[61]  arXiv:2003.01723 (cross-list from hep-ph) [pdf, other]

Title: Neutrino Portal to FIMP Dark Matter with an Early Matter Era

Authors: Catarina Cosme, Maíra Dutra, Teng Ma, Yongcheng Wu, Litao Yang

Comments: 38 pages, 11 figures

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

We study the freeze-in production of Feebly Interacting Massive Particle (FIMP) dark matter candidates through a neutrino portal. We consider a hidden sector comprised of a fermion and a complex scalar, with the lightest one regarded as a FIMP candidate. We implement the Type-I Seesaw mechanism for generating the masses of the Standard Model (SM) neutrinos and consider three heavy neutrinos, responsible for mediating the interactions between the hidden and the SM sectors. We assume that an early matter-dominated era (EMDE) took place for some period between inflation and Big Bang Nucleosynthesis, making the Universe to expand faster than in the standard radiation-dominated era. In this case, the hidden and SM sectors are easily decoupled and larger couplings between FIMPs and SM particles are needed from the relic density constraints. In this context, we discuss the dynamics of dark matter throughout the modified cosmic history, evaluate the relevant constraints of the model and discuss the consequences of the duration of the EMDE for the dark matter production. Finally, we show that if the heavy neutrinos are not part of the thermal bath, this scenario becomes testable through indirect detection searches.

[62]  arXiv:2003.01926 (cross-list from stat.ML) [pdf, other]

Title: Transformation Importance with Applications to Cosmology

Authors: Chandan Singh, Wooseok Ha, Francois Lanusse, Vanessa Boehm, Jia Liu, Bin Yu

Comments: Accepted to ICLR 2020 Workshop on Fundamental Science in the era of AI

Subjects: Machine Learning (stat.ML); Instrumentation and Methods for Astrophysics (astro-ph.IM); Machine Learning (cs.LG)

Machine learning lies at the heart of new possibilities for scientific discovery, knowledge generation, and artificial intelligence. Its potential benefits to these fields requires going beyond predictive accuracy and focusing on interpretability. In particular, many scientific problems require interpretations in a domain-specific interpretable feature space (e.g. the frequency domain) whereas attributions to the raw features (e.g. the pixel space) may be unintelligible or even misleading. To address this challenge, we propose TRIM (TRansformation IMportance), a novel approach which attributes importances to features in a transformed space and can be applied post-hoc to a fully trained model. TRIM is motivated by a cosmological parameter estimation problem using deep neural networks (DNNs) on simulated data, but it is generally applicable across domains/models and can be combined with any local interpretation method. In our cosmology example, combining TRIM with contextual decomposition shows promising results for identifying which frequencies a DNN uses, helping cosmologists to understand and validate that the model learns appropriate physical features rather than simulation artifacts.

[63]  arXiv:2003.01934 (cross-list from gr-qc) [pdf, ps, other]

Title: Extended Cuscuton as Dark Energy

Authors: Aya Iyonaga, Kazufumi Takahashi, Tsutomu Kobayashi

Comments: 11 pages, 2figures

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

Late-time cosmology in the extended cuscuton theory is studied, in which gravity is modified while one still has no extra dynamical degrees of freedom other than two tensor modes. We present a simple example admitting analytic solutions for the cosmological background evolution that mimics $\Lambda$CDM cosmology. We argue that the extended cuscuton as dark energy can be constrained, like usual scalar-tensor theories, by the growth history of matter density perturbations and the time variation of Newton's constant.

[64]  arXiv:2003.02028 (cross-list from hep-th) [pdf, other]

Title: A domain wall description of brane inflation and observational aspects

Authors: R. M. P. Neves, F. F. Santos, F. A. Brito

Comments: 8 pages, 1 figure

Subjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

We consider a brane cosmology scenario by taking an inflating 3D domain wall immersed in a five-dimensional Minkowski space in the presence of a stack of $N$ parallel domain walls. They are static BPS solutions of the bosonic sector of a 5D supergravity theory. However, one can move towards each other due to an attractive force in between driven by bulk particle collisions and {\it resonant tunneling effect}. The accelerating domain wall is a 3-brane that is assumed to be our inflating early Universe. We analyze this inflationary phase governed by the inflaton potential induced on the brane. We compute the slow-roll parameters and show that the spectral index and the tensor-to-scalar ratio are within the recent observational data.

[65]  arXiv:2003.02098 (cross-list from physics.chem-ph) [pdf, other]

Title: Perturbation of the Surface of Amorphous Solid Water by the Adsorption of Polycyclic Aromatic Hydrocarbons

Authors: E Michoulier, C Toubin, A Simon, J Mascetti, C Aupetit, J A Noble

Comments: Published in J. Phys. Chem. C

Subjects: Chemical Physics (physics.chem-ph); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

This joint theoretical and experimental study establishes that the adsorption of polycyclic aromatic hydrocarbons (PAHs) onto the amorphous ice surface provokes a broadening and redshift of the "dangling" OH (dOH) ice spectral feature, the redshift increasing with PAH size up to $\sim$ 85~cm$^{-1}$. It also reveals that, in certain interaction configurations, adsorption induces substantial reorganisation of the hydrogen-bonding network at the ice surface. Comparison with experiments validates the novel theoretical methodology relying on the density functional based tight binding approach, which offers a compromise between system size and accuracy enabling a wide sampling of surface structures. Applied in an astrophysical context, this study suggests that widening of the dOH feature by adsorption of aromatic molecules could explain its absence heretofore in observational ice spectra, offering hope that future missions with higher sensitivity will verify its presence or absence in dense regions.

[66]  arXiv:2003.02141 (cross-list from hep-ph) [pdf, other]

Title: Dark origins of matter-antimatter asymmetry

Authors: Venus Keus

Comments: 15 pages, 8 figures. arXiv admin note: substantial text overlap with arXiv:1909.09234

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

In a non-minimal Higgs framework, we present a novel mechanism in which the CP violating dark particles only interact with the SM through the gauge bosons, primarily the $Z$ boson. Such $Z$-portal dark CP violation is realised in the regions of the parameter space where Higgs-mediated (co)annihilation processes are sub-dominant and have negligible contributions to the DM relic density. We show that such $Z$-portal CP violating DM can still thermalise and satisfy all experimental and observational bounds and discuss implications of such phenomena for electroweak baryogenesis.

[67]  arXiv:2003.02257 (cross-list from gr-qc) [pdf, ps, other]

Title: Irreversible thermodynamical description of warm inflationary cosmological models

Authors: Tiberiu Harko, Haidar Sheikhahmadi

Comments: 33 pages, 22 figures, accepted for publication in Physics of the Dark Universe

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

We investigate the interaction between scalar fields and radiation in the framework of warm inflationary models by using the irreversible thermodynamics of open systems with matter creation/annihilation. We consider the scalar fields and radiation as an interacting two component cosmological fluid in a homogeneous, spatially flat and isotropic Friedmann-Robertson-Walker (FRW) Universe. The thermodynamics of open systems as applied together with the gravitational field equations to the two component cosmological fluid leads to a generalization of the elementary scalar field-radiation interaction model, which is the theoretical basis of warm inflationary models, with the decay (creation) pressures explicitly considered as parts of the cosmological fluid energy-momentum tensor. Specific models describing coherently oscillating scalar waves, scalar fields with a constant potential, and scalar fields with a Higgs type potential are considered in detail. For each case exact and numerical solutions of the gravitational field equations with scalar field-radiation interaction are obtained, and they show the transition from an accelerating inflationary phase to a decelerating one. The theoretical predictions of the warm inflationary scenario with irreversible matter creation are also compared in detail with the Planck 2018 observational data, and constraints on the free parameters of the model are obtained.

Replacements for Thu, 5 Mar 20

[68]  arXiv:1904.01958 (replaced) [pdf, other]

Title: Axion resonances in binary pulsar systems

Authors: Mor Rozner, Evgeni Grishin, Yonadav Barry Ginat, Andrei P. Igoshev, Vincent Desjacques

Comments: clarifications added, in press in JCAP

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)

[69]  arXiv:1906.03566 (replaced) [pdf, ps, other]

Title: Energy extraction and particle acceleration around a rotating dyonic black hole in $N=2$, $U(1)^2$ gauged supergravity

Authors: Anik Rudra, Hemwati Nandan, Radouane Gannouji, Soham Chakraborty, Arindam Kumar Chatterjee

Comments: 20 pages, 16 figures, 6 tables. Completely new abstract, Conclusion with major changes to BSW effect are made along with the corrections of few typos

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE)

[70]  arXiv:1906.05164 (replaced) [pdf, ps, other]

Title: Relativistic approach to the kinematics of large-scale peculiar motions

Authors: Eleni Tsaprazi, Christos G. Tsagas

Comments: 14 pages. Revised and extended version

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)

[71]  arXiv:1907.02107 (replaced) [pdf, other]

Title: Solar cycle prediction

Authors: Kristof Petrovay

Comments: 96 pages, 15 figures, 2 tables. Revised edition of 2010 living review arXiv:1012.5513, in press

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

[72]  arXiv:1908.01195 (replaced) [pdf, ps, other]

Title: Five dimensional charged rotating minimally gauged supergravity black hole cannot be over-spun and/or over-charged in non-linear accretion

Authors: Sanjar Shaymatov, Naresh Dadhich, Bobomurat Ahmedov, Mubasher Jamil

Comments: 12 pages, no figures; v2: some inaccurate statements have been corrected, the result remains unaltered

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)

[73]  arXiv:1908.04146 (replaced) [pdf, other]

Title: Big Bang Nucleosynthesis Hunts Chameleon Dark Matter

Authors: Hua Chen, Taishi Katsuragawa, Shinya Matsuzaki, Taotao Qiu

Comments: 29 pages, 7 figures, Prepared for submission to JHEP

Journal-ref: JHEP 2002 (2020) 155

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[74]  arXiv:1908.05833 (replaced) [pdf, other]

Title: The Kepler Peas in a Pod Pattern is Astrophysical

Authors: Lauren M. Weiss, Erik A. Petigura

Comments: Accepted for publication in ApJ Letters; 11 pages, 4 figures

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

[75]  arXiv:1908.06832 (replaced) [pdf, other]

Title: The influence of a top-heavy integrated galactic IMF and dust on the chemical evolution of high-redshift starbursts

Authors: Marco Palla, Francesco Calura, Francesca Matteucci, XiLong Fan, Fiorenzo Vincenzo, Elena Lacchin

Comments: 20 pages, 14 Figures

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[76]  arXiv:1908.10369 (replaced) [pdf, ps, other]

Title: Constraining Nonthermal Dark Matter's Impact on the Matter Power Spectrum

Authors: Carisa Miller, Adrienne Erickcek, Riccardo Murgia

Comments: To be submitted to PRD; 14 pages, 13 figures; Updated to match published version

Journal-ref: Phys. Rev. D 100, 123520 (2019)

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[77]  arXiv:1909.04971 (replaced) [pdf, ps, other]

Title: SMA Observations of Haro 2: Molecular Gas around a Hot Superbubble

Authors: Sara C. Beck, Pei-Ying Hsieh, Jean Turner

Comments: Submitted to MNRAS 9/9/2019, Revised version accepted 2/3/2020

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[78]  arXiv:1909.06375 (replaced) [pdf, other]

Title: Lifetime of short-period binaries measured from their Galactic kinematics

Authors: Hsiang-Chih Hwang, Nadia Zakamska

Comments: Accepted for publication in MNRAS. Figure 5 is the key result

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

[79]  arXiv:1909.10524 (replaced) [pdf, other]

Title: Weak lensing Analysis of X-Ray-selected XXL Galaxy Groups and Clusters with Subaru HSC Data

Authors: Keiichi Umetsu (ASIAA), Mauro Sereno, Maggie Lieu, Hironao Miyatake, Elinor Medezinski, Atsushi J. Nishizawa, Paul Giles, Fabio Gastaldello, Ian G. McCarthy, Martin Kilbinger, Mark Birkinshaw, Stefano Ettori, Nobuhiro Okabe, I-Non Chiu, Jean Coupon, Dominique Eckert, Yutaka Fujita, Yuichi Higuchi, Elias Koulouridis, Ben Maughan, Satoshi Miyazaki, Masamune Oguri, Florian Pacaud, Marguerite Pierre, David Rapetti, Graham P. Smith

Comments: Version matching the one published in ApJ. We recommend to use statistically corrected mass estimates (M200MT, M500MT) of Table 2 for a given individual cluster. One of two companion papers presenting initial HSC-XXL results (Mauro Sereno et al., arXiv:1912.02827)

Journal-ref: ApJ, 890, 148 (2020)

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)

[80]  arXiv:1910.01238 (replaced) [pdf, other]

Title: Strong Dark Matter Self-Interaction from a Stable Scalar Mediator

Authors: Mateusz Duch, Bohdan Grzadkowski, Da Huang

Comments: 25 pages, 6 figures

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[81]  arXiv:1910.06978 (replaced) [pdf, other]

Title: New class of generalized coupling theories

Authors: Justin C. Feng, Sante Carloni

Comments: 19 pages, 1 table, 3 figures. Minor revisions, added references. Matches published version

Journal-ref: Phys. Rev. D 101, 064002 (2020)

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

[82]  arXiv:1910.08837 (replaced) [pdf, other]

Title: Trans-Planckian Censorship and Inflation in Grand Unified Theories

Authors: Kai Schmitz

Comments: 10 pages. v2: additional paragraph on the weak-gravity conjecture, matches version published in PLB

Journal-ref: Phys. Lett. B 803, 135317 (2020)

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

[83]  arXiv:1910.12173 (replaced) [pdf, other]

Title: Model-independent constraints on cosmic curvature from strong gravitational lensing and type Ia supernova observations

Authors: Bo Wang, Jing-Zhao Qi, Jing-Fei Zhang, Xin Zhang

Comments: 10 pages, 4 figures

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)

[84]  arXiv:1912.09496 (replaced) [pdf, other]

Title: On the delivery of DART-ejected material from asteroid (65803) Didymos to Earth

Authors: Paul Wiegert

Comments: 12 pages, 5 figures, 2 animated figures. Accepted by the Planetary Science journal. Updated to reflect changes in the accepted version

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

[85]  arXiv:1912.12473 (replaced) [pdf, other]

Title: Hunting dark matter in galaxy clusters with non-thermal electrons

Authors: Geoff Beck

Comments: 5 pages, 3 figures

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)

[86]  arXiv:2001.02474 (replaced) [pdf, other]

Title: Squeezing of primordial gravitational waves as quantum discord

Authors: Akira Matsumura, Yasusada Nambu

Comments: 33 pages, 10 figures

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Quantum Physics (quant-ph)

[87]  arXiv:2001.02897 (replaced) [pdf, ps, other]

Title: Second law of black hole thermodynamics

Authors: Koji Azuma, Go Kato

Comments: 7 pages, 1 figure

Subjects: High Energy Physics - Theory (hep-th); High Energy Astrophysical Phenomena (astro-ph.HE); Statistical Mechanics (cond-mat.stat-mech); General Relativity and Quantum Cosmology (gr-qc); Quantum Physics (quant-ph)

[88]  arXiv:2001.03620 (replaced) [pdf, other]

Title: Gravitational-wave detection and parameter estimation for accreting black-hole binaries and their electromagnetic counterpart

Authors: Andrea Caputo, Laura Sberna, Alexandre Toubiana, Stanislav Babak, Enrico Barausse, Sylvain Marsat, Paolo Pani

Comments: 14 pages, 8 figures; v2: references and comments added to match the version accepted for publication in ApJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)

[89]  arXiv:2001.05776 (replaced) [pdf, other]

Title: Environmental processing in cluster core galaxies at z=1.7

Authors: G. Castignani, F. Combes, P. Salomé

Comments: 6 pages, 3 figures, accepted for publication in A&A Letters

Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[90]  arXiv:2001.10758 (replaced) [pdf, ps, other]

Title: Fast radio bursts as strong waves interacting with ambient medium

Authors: Yuan-Pei Yang, Bing Zhang

Comments: 8 pages, 3 figures, accepted for publication in ApJL

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

[91]  arXiv:2002.02464 (replaced) [pdf, other]

Title: Cosmology with quasars: predictions for eROSITA from a quasar Hubble diagram

Authors: Elisabeta Lusso (UniFI/INAF-Arcetri)

Comments: 9 pages, 2 figures, Frontiers in Astronomy and Space Sciences in press (research topic: Quasars in Cosmology). Abstract abridged. Amended version after profs

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[92]  arXiv:2002.04864 (replaced) [pdf, other]

Title: High Dynamic Range Spatial Mode Decomposition

Authors: A. W. Jones, M. Wang, C. M. Mow-Lowry, A. Freise

Subjects: Instrumentation and Detectors (physics.ins-det); Instrumentation and Methods for Astrophysics (astro-ph.IM); Optics (physics.optics)

[93]  arXiv:2002.06045 (replaced) [pdf, ps, other]

Title: No nitrogen fractionation on 600 au scale in the Sun progenitor analogue OMC-2 FIR4

Authors: F. Fontani, G. Quaia, C. Ceccarelli, L. Colzi, A. Lopez-Sepulcre, C. Favre, C. Kahane, P. Caselli, C. Codella, L. Podio, S. Viti

Comments: 10 pages, 5 figures, accepted for publication by MNRAS

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

[94]  arXiv:2002.08028 (replaced) [pdf, other]

Title: Variability and the size-luminosity relation of the intermediate mass AGN in NGC 4395

Authors: Hojin Cho, Jong-Hak Woo, Edmund Hodges-Kluck, Donghoon Son, Jaejin Shin, Elena Gallo, Hyun-Jin Bae, Thomas G. Brink, Wanjin Cho, Alexei V. Filippenko, John C. Horst, Dragana Ilić, Michael. D. Joner, Daeun Kang, Wonseok Kang, Shai Kaspi, Taewoo Kim, Andjelka B. Kovačević, Sahana Kumar, Huynh Anh N. Le, A. E. Nadzhip, Francisco Pozo Nuñez, V.G. Metlov, V. L. Oknyansky, Songyoun Park, Luka Č. Popović, Suvendu Rakshit, Malte Schramm, N. I. Shatsky, Michelle Spencer, Eon-Chang Sung, Hyun-il Sung, A. M. Tatarnikov, Oliver Vince

Comments: Accepted for publication in ApJ (Feb. 23rd, 2020). 18 pages, 10 figures

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[95]  arXiv:2003.00079 (replaced) [pdf, other]

Title: Dust depleted inner disks in a large sample of transition disks through long-baseline ALMA observations

Authors: Logan Francis, Nienke van der Marel

Comments: 31 pages, 14 figures, accepted for publication in the Astrophysical Journal, minor corrections

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

• New submissions
• Cross-lists
• Replacements