Astrophysics
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New submissions for Wed, 3 Jun 20
- [1] arXiv:2006.01123 [pdf, ps, other]
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Title: Optical spectroscopy and photometry of main-belt asteroids with a high orbital inclinationJournal-ref: Research in Astronomy and Astrophysics, Volume 17, Issue 2, article id. 17 (2017)Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
We carried out low-resolution optical spectroscopy of 51 main-belt asteroids, most of which have highly-inclined orbits. They are selected from D-type candidates in the SDSS-MOC 4 catalog. Using the University of Hawaii 2.2 m telescope and the Inter-University Centre for Astronomy and Astrophysics 2 m telescope in India, we determined the spectral types of 38 asteroids. Among them, eight asteroids were classified as D-type asteroids. Fractions of D-type asteroids are 3.0+/-1.1 for low orbital inclination main-belt asteroids and 7.3+/-2.0 for high orbital inclination main-belt asteroids. The results of our study indicate that some D-type asteroids were formed within the ecliptic region between the main belt and Jupiter, and were then perturbed by Jupiter.
- [2] arXiv:2006.01124 [pdf, ps, other]
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Title: High-Resolution Spectroscopy of Winds Associated with T Tauri StarsJournal-ref: Research in Astronomy and Astrophysics, Volume 16, Issue 2, article id. 30 (2016)Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
We carried out optical high-resolution spectroscopy of T Tauri stars using the Subaru Telescope. Using archived data from the Keck Telescope and the Very Large Telescope, we detected forbidden lines of [S II] at 4069 A, in addition to those of [O I] at 5577 A and 6300 A, for 13 T Tauri stars. We consider that low-velocity components of these forbidden lines emanate from the wind associated with T Tauri stars. Using two flux ratios of the three lines, we simultaneously determined the hydrogen density and temperature of the winds. The winds of T Tauri stars have a hydrogen density of $2.5 \times 10^{6}$ cm$^{-3}$ - $2.5 \times 10^{9}$ cm$^{-3}$ and a temperature of 10800 -18000 K. The mass loss rates by the wind are estimated to lie in the range from $2.0 \times 10^{-10}$ M$_{\odot}$ yr$^{-1}$ to $1.4 \times 10^{-9}$ M$_{\odot}$ yr$^{-1}$. The mass loss rates are found to increase with increasing mass accretion rates. The ratio of the mass loss rate to the mass accretion rate is 0.001-0.1 for classical T Tauri stars and 0.1-1 for transitional disk objects.
- [3] arXiv:2006.01145 [pdf, other]
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Title: Bremsstrahlung in GRMHD models of accreting black holesAuthors: R. Yarza (1 and 2), G. N. Wong (1), B. R. Ryan (3), C. F. Gammie (1 and 2) ((1) Department of Physics, University of Illinois, (2) Department of Astronomy, University of Illinois, (3) CCS-2, Los Alamos National Laboratory)Comments: 10 pages, 5 figures, accepted for publication in ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
The role of bremsstrahlung in the emission from hot accretion flows around slowly accreting supermassive black holes is not thoroughly understood. In order to appraise the importance of bremsstrahlung relative to other radiative processes, we compute spectral energy distributions (SEDs) of accretion disks around slowly accreting supermassive black holes including synchrotron radiation, inverse Compton scattering, and bremsstrahlung. We compute SEDs for (i) four axisymmetric radiative general relativistic magnetohydrodynamics (RadGRMHD) simulations of $10^{8}M_{\odot}$ black holes with accretion rates between $10^{-8}\dot{M}_{\text{Edd}}$ and $10^{-5}\dot{M}_{\text{Edd}}$, (ii) four axisymmetric RadGRMHD simulations of M87$^\ast$ with varying dimensionless spin $a_\ast$ and black hole mass, and (iii) a 3D GRMHD simulation scaled for Sgr A$^\ast$. At $10^{-8}\dot{M}_{\text{Edd}}$, most of the luminosity is synchrotron radiation, while at $10^{-5}\dot{M}_{\text{Edd}}$ the three radiative processes have similar luminosities. In most models, bremsstrahlung dominates the SED near $512\text{ keV}$. In the M87$^\ast$ models, bremsstrahlung dominates this part of the SED if $a_{\ast} = 0.5$, but inverse Compton scattering dominates if $a_{\ast}= 0.9375$. Since scattering is more variable than bremsstrahlung, this result suggests that $512\text{ keV}$ variability could be a diagnostic of black hole spin. In the appendix, we compare some bremsstrahlung formulae found in the literature.
- [4] arXiv:2006.01146 [pdf, other]
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Title: Galaxy Bias and $σ_8$ from Counts in Cells from the SDSS Main SampleComments: 5 pages, 3 figures; submitted to MNRASSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)
The counts-in-cells (CIC) galaxy probability distribution depends on both the dark matter clustering amplitude $\sigma_8$ and the galaxy bias $b$. We present a theory for the CIC distribution based on a previous prescription of the underlying dark matter distribution and a linear volume transformation to redshift space. We show that, unlike the power spectrum, the CIC distribution breaks the degeneracy between $\sigma_8$ and $b$ on scales large enough that both bias and redshift distortions are still linear; thus we obtain a simultaneous fit for both parameters. We first validate the technique on the Millennium Simulation and then apply it to the SDSS Main Galaxy Sample. We find $\sigma_8 = 0.94^{+.11}_{-.10}$ and $b = 1.36^{+.14}_{-.11}$, consistent with previous complementary results from redshift distortions and from Planck.
- [5] arXiv:2006.01147 [pdf, other]
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Title: ALMA [N ıı] 205 μm Imaging Spectroscopy of the Lensed Submillimeter galaxy ID 141 at redshift 4.24Authors: Cheng Cheng, Xiaoyue Cao, Nanyao Lu, Ran Li, Chentao Yang, Dimitra Rigopoulou, Vassilis Charmandaris, Yu Gao, Cong Kevin Xu, Paul van der Werf, Tanio Diaz Santos, George C. Privon, Yinghe Zhao, Tianwen Cao, Y. Sophia Dai, Jia-Sheng Huang, David Sanders, Chunxiang Wang, Zhong Wang, Lei ZhuComments: 13 pages, 6 figures, 2 tables, accepted by ApJ, lensing model code can be found here this https URLSubjects: Astrophysics of Galaxies (astro-ph.GA)
We present the Atacama Large Millimeter/submillimeter Array (ALMA) observation of the Sub-millimeter galaxy (SMG) ID 141 at z=4.24 in the [N II] 205 $\mu$m line (hereafter [N II]) and the underlying continuum at (rest-frame) 197.6 $\mu$m. Benefiting from lensing magnification by a galaxy pair at z=0.595, ID 141 is one of the brightest z$>4$ SMGs. At the angular resolutions of $\sim1.2''$ to $1.5''$ ($1'' \sim6.9$ kpc), our observation clearly separates, and moderately resolves the two lensed images in both continuum and line emission at $\rm S/N>5$ . Our continuum-based lensing model implies an averaged amplification factor of $\sim5.8$ and reveals that the de-lensed continuum image has the S\'ersic index $\simeq 0.95$ and the S\'ersic radius of $\sim0.18'' (\sim 1.24$ kpc). Furthermore, the reconstructed [N II] velocity field in the source plane is dominated by a rotation component with a maximum velocity of $\sim 300$ km/s at large radii, indicating a dark matter halo mass of $\sim 10^{12}M_{\odot}$. This, together with the reconstructed velocity dispersion field being smooth and modest in value ($<100$ km/s) over much of the outer parts of the galaxy, favours the interpretation of ID 141 being a disk galaxy dynamically supported by rotation. The observed [N II]/CO (7-6) and [N II]/[C II] 158 $\mu$m line luminosity ratios, which are consistent with the corresponding line ratio vs. far-infrared color correlation from local luminous infrared galaxies, imply a de-lensed star formation rate of ($1.8\pm 0.6)\times10^3M_\odot$/yr and provide an independent estimate on the size of the star-forming region $0.7^{+0.3}_{-0.3}$ kpc in radius.
- [6] arXiv:2006.01150 [pdf, other]
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Title: A thousand days after the merger: continued X-ray emission from GW170817Authors: E. Troja, H. van Eerten, B. Zhang, G. Ryan, L. Piro, R. Ricci, B. O'Connor, M. H. Wieringa, S. B. Cenko, T. SakamotoComments: 10 pages, 6 figures, 2 tables, submitted to MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Recent observations with the Chandra X-ray telescope continue to detect X-ray emission from the transient GW170817. In a total exposure of 96.6 ks, performed between March 9 and March 16 2020 (935 d to 942 d after the merger), a total of 8 photons are measured at the source position, corresponding to a significance of about 5 sigma. Radio monitoring with the Australian Telescope Compact Array (ATCA) shows instead that the source has faded below our detection threshold (<33 uJy, 3 sigma). By assuming a constant spectral index beta=0.585, we derive an unabsorbed X-ray flux of approximately 1.4E-15 erg/cm^2/s, higher than earlier predictions, yet still consistent with a simple structured jet model. We discuss possible scenarios that could account for prolonged emission in X-rays. The current dataset appears consistent both with energy injection by a long-lived central engine and with the onset of a kilonova afterglow, arising from the interaction of the sub-relativistic merger ejecta with the surrounding medium. Long-term monitoring of this source will be essential to test these different models.
- [7] arXiv:2006.01154 [pdf, other]
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Title: The weak imprint of environment on the stellar populations of galaxiesAuthors: James Trussler, Roberto Maiolino, Claudia Maraston, Yingjie Peng, Daniel Thomas, Daniel Goddard, Jianhui LianComments: 25 pages, 19 figures, submitted to MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
We investigate the environmental dependence of the stellar populations of galaxies in SDSS DR7. Echoing earlier works, we find that satellites are both more metal-rich (<0.1 dex) and older (<2 Gyr) than centrals of the same stellar mass. However, after separating star-forming, green valley and passive galaxies, we find that the true environmental dependence of both stellar metallicity (<0.03 dex) and age (<0.5 Gyr) is in fact much weaker. We show that the strong environmental effects found when galaxies are not differentiated result from a combination of selection effects brought about by the environmental dependence of the quenched fraction of galaxies, and thus we strongly advocate for the separation of star-forming, green valley and passive galaxies when the environmental dependence of galaxy properties are investigated. We also study further environmental trends separately for both central and satellite galaxies. We find that star-forming galaxies show no environmental effects, neither for centrals nor for satellites. In contrast, the stellar metallicities of passive and green valley satellites increase weakly with increasing halo mass, increasing local overdensity and decreasing projected distance from their central; this effect is interpreted in terms of moderate environmental starvation (`strangulation') contributing to the quenching of satellite galaxies. Finally, we find a unique feature in the stellar mass--stellar metallicity relation for passive centrals, where galaxies in more massive haloes have larger stellar mass at constant stellar metallicity; this effect is interpreted in terms of dry merging of passive central galaxies and/or progenitor bias.
- [8] arXiv:2006.01157 [pdf, other]
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Title: A Multilevel Empirical Bayesian Approach to Estimating the Unknown Redshifts of 1366 BATSE Catalog Long-Duration Gamma-Ray BurstsComments: 53 pages, 8 figures, 2 tables, submitted to the Astrophysical Journal. This article is a continuation of and builds upon arXiv:1903.06989 [astro-ph.HE]Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM); Data Analysis, Statistics and Probability (physics.data-an)
We present a catalog of the probabilistic redshift estimates and for 1366 individual Long-duration Gamma-Ray Bursts (LGRBs) detected by the Burst And Transient Source Experiment (BATSE). This result is based on a careful selection and modeling of the population distribution of 1366 BATSE LGRBs in the 5-dimensional space of redshift and the four intrinsic prompt gamma-ray emission properties: the isotropic 1024ms peak luminosity, the total isotropic emission, the spectral peak energy, as well as the intrinsic duration, while carefully taking into account the effects of sample incompleteness and the LGRB-detection mechanism of BATSE. Two fundamental plausible assumptions underlie our purely-probabilistic approach: 1. LGRBs trace, either exactly or closely, the Cosmic Star Formation Rate and 2. the joint 4-dimensional distribution of the aforementioned prompt gamma-ray emission properties is well-described by a multivariate log-normal distribution.
Our modeling approach enables us to constrain the redshifts of individual BATSE LGRBs to within $0.36$ and $0.96$ average uncertainty ranges at $50\%$ and $90\%$ confidence levels, respectively. Our redshift predictions are completely at odds with the previous redshift estimates of BATSE LGRBs that were computed via the proposed phenomenological high-energy relations, specifically, the apparently-strong correlation of LGRBs' peak luminosity with the spectral peak energy, lightcurve variability, and the spectral lag. The observed discrepancies between our predictions and the previous works can be explained by the strong influence of detector threshold and sample-incompleteness in shaping these phenomenologically-proposed high-energy correlations in the literature. - [9] arXiv:2006.01158 [pdf, other]
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Title: The age distribution of stars in the Milky Way bulgeComments: Submitted to ApJ. 17 pages, 23 figuresSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
The age and chemical characteristics of the Galactic bulge link to the formation and evolutionary history of the Galaxy. Data-driven methods and large surveys enable stellar ages and precision chemical abundances to be determined for vast regions of the Milky Way, including the bulge. Here, we use the data-driven approach of The Cannon, to infer the ages and abundances for 125,367 stars in the Milky Way, using spectra from APOGEE DR14. We examine the ages and metallicities of 1654 bulge stars within $R_{\text{GAL}}<3.5$ kpc. We focus on fields with $b<12^\circ$, and out to longitudes of $l<15^\circ$. We see that stars in the bulge are about twice as old ($\tau=8$ Gyrs), on average, compared to those in the solar neighborhood ($\tau=4$ Gyrs), with a larger dispersion in [Fe/H] ($\approx0.38$ compared to 0.23 dex). This age gradient comes primarily from the low-$\alpha$ stars. Looking along the Galactic plane, the very central field in the bulge shows by far the largest dispersion in [Fe/H] ($\sigma_{[Fe/H]}\approx0.4$ dex) and line of sight velocity ($\sigma_{vr}\approx90$ km/s), and simultaneously the smallest dispersion in age. Moving out in longitude, the stars become kinematically colder and less dispersed in [Fe/H], but show a much broader range of ages. We see a signature of the X-shape within the bulge at a latitude of $b=8^\circ$, but not at $b=12^\circ$. Future APOGEE and other survey data, with larger sampling, affords the opportunity to extend our approach and study in more detail, to place stronger constraints on models of the Milky Way.
- [10] arXiv:2006.01159 [pdf, other]
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Title: Radio Properties of Tidal Disruption EventsAuthors: Kate D. Alexander (Northwestern/CIERA, NASA Einstein Fellow), Sjoert van Velzen (NYU), Assaf Horesh (Racah Institute), B. Ashley Zauderer (NSF, DARK)Comments: Resubmitted for publication in Springer Space Science Reviews following referee comments. Chapter in ISSI review "The Tidal Disruption of Stars by Massive Black Holes" vol. 79. Table 2 is available in machine-readable format upon requestSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Radio observations of tidal disruption events (TDEs) probe material ejected by the disruption of stars by supermassive black holes (SMBHs), uniquely tracing the formation and evolution of jets and outflows, revealing details of the disruption hydrodynamics, and illuminating the environments around previously-dormant SMBHs. To date, observations reveal a surprisingly diverse population. A small fraction of TDEs (at most a few percent) have been observed to produce radio-luminous mildly relativistic jets. The remainder of the population are radio quiet, producing less luminous jets, non-relativistic outflows or, possibly, no radio emission at all. Here, we review the radio observations that have been made of TDEs to date and discuss possible explanations for their properties, focusing on detected sources and, in particular, on the two best-studied events: Sw J1644+57 and ASASSN-14li. We also discuss what we have learned about the host galaxies of TDEs from radio observations and review constraints on the rates of bright and faint radio outflows in TDEs. Upcoming X-ray, optical, near-IR, and radio surveys will greatly expand the sample of TDEs, and technological advances open the exciting possibility of discovering a sample of TDEs in the radio band unbiased by host galaxy extinction.
- [11] arXiv:2006.01161 [pdf, other]
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Title: The CMB Rayleigh-Jeans tail as a detector of high-frequency gravitational wavesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
In the presence of magnetic fields, gravitational waves are converted into photons and vice versa. We demonstrate that this conversion leads to a distortion of the cosmic microwave background (CMB), which can serve as a detector for MHz to GHz gravitational wave sources active before reionization. The measurements of the radio telescope EDGES can be cast as a bound on the gravitational wave amplitude, $h_c < 10^{-21} (10^{-12})$ at 78 MHz, for the strongest (weakest) cosmic magnetic fields allowed by current astrophysical and cosmological constraints. Similarly, the results of ARCADE 2 imply $h_c < 10^{-24} (10^{-14})$ at $3 - 30$ GHz. For the strongest magnetic fields, these constraints exceed current laboratory constraints by about seven orders of magnitude. Future advances in 21cm astronomy may conceivably push these bounds below the sensitivity of cosmological constraints on the total energy density of gravitational waves.
- [12] arXiv:2006.01165 [pdf, other]
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Title: BBN constraints on dark radiation isocurvatureComments: 8 pages + 4 pages appendixSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
The existence of dark radiation that is completely decoupled from the standard model in the early Universe leaves open the possibility of an associated dark radiation isocurvature mode. We show that the presence of dark radiation isocurvature leads to spatial variation in the primordial abundances of helium and deuterium due to spatial variation in $N_{\rm eff}$ during Big Bang nucleosynthesis. We use the result to constrain the existence of such an isocurvature mode on scales down to $\sim 1$ Mpc scales. By measuring the excess variance in the primordial helium to hydrogen and deuterium to hydrogen ratio in different galaxies, we constrain the variance in average isocurvature in a galaxy to be less than $0.13/\Delta \bar{N}_{\rm eff}$ at 95\% confidence. Here $\Delta \bar{N}_{\rm eff}$ is the spatially averaged increase in $N_{\rm eff}$ due to the additional dark radiation component.
- [13] arXiv:2006.01194 [pdf, other]
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Title: Ring formation and dust dynamics in wind-driven protoplanetary discs: global simulationsComments: 17 pages, accepted in A&ASubjects: Earth and Planetary Astrophysics (astro-ph.EP); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
Large-scale vertical magnetic fields are believed to play a key role in the evolution of protoplanetary discs. Associated with non-ideal effects, such as ambipolar diffusion, they are known to launch a wind that could drive accretion in the outer part of the disc ($R> 1$ AU). They also potentially lead to self-organisation of the disc into large-scale axisymmetric structures, similar to the rings recently imaged by sub-millimetre or near-infrared instruments (ALMA and SPHERE). The aim of this paper is to investigate the mechanism behind the formation of these gaseous rings, but also to understand the dust dynamics and its emission in discs threaded by a large-scale magnetic field. To this end, we performed global magneto-hydrodynamics (MHD) axisymmetric simulations with ambipolar diffusion using a modified version of the PLUTO code. We explored different magnetisations with the midplane $\beta$ parameter ranging from $10^5$ to $10^3$ and included dust grains -- treated in the fluid approximation -- ranging from $100 \mu$m to 1 cm in size. We first show that the gaseous rings (associated with zonal flows) are tightly linked to the existence of MHD winds. Secondly, we find that millimetre-size dust is highly sedimented, with a typical scale height of 1 AU at $R=100$ AU for $\beta=10^4$, compatible with recent ALMA observations. We also show that these grains concentrate into pressure maxima associated with zonal flows, leading to the formation of dusty rings. Using the radiative transfer code MCFOST, we computed the dust emission and make predictions on the ring-gap contrast and the spectral index that one might observe with interferometers like ALMA.
- [14] arXiv:2006.01196 [pdf, other]
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Title: Establishing the impact of powerful AGN on their host galaxiesComments: Invited Contribution to IAU Symposium 359 (T. Storchi-Bergmann, R. Overzier, W. Forman & R. Riffel, eds.)Subjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
Establishing the role of active galactic nuclei (AGN) during the formation of galaxies remains one of the greatest challenges of galaxy formation theory. Towards addressing this, we summarise our recent work investigating: (1) the physical drivers of ionised outflows and (2) observational signatures of the impact by jets/outflows on star formation and molecular gas content in AGN host galaxies. We confirm a connection between radio emission and extreme ionised gas kinematics in AGN hosts. Emission-line selected AGN are significantly more likely to exhibit ionised outflows (as traced by the [O III] emission line) if the projected linear extent of the radio emission is confined within the spectroscopic aperture. Follow-up high resolution radio observations and integral field spectroscopy of 10 luminous Type 2 AGN reveal moderate power, young (or frustrated) jets interacting with the interstellar medium. We find that these sources live in highly star forming and gas rich galaxies. Additionally, by combining ALMA-derived dust maps with integral field spectroscopy for eight host galaxies of z~2 X-ray AGN, we show that H-alpha emission is an unreliable tracer of star formation. For the five targets with ionised outflows we find no dramatic in-situ shut down of the star formation. Across both of these studies we find that if these AGN do have a negative impact upon their host galaxies, it must be happening on small (unresolved) spatial scales and/or an observable galaxy-wide impact has yet to occur.
- [15] arXiv:2006.01199 [pdf, other]
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Title: Classifying Single Stars and Spectroscopic Binaries Using Optical Stellar TemplatesComments: 16 pages, 7 figures, 4 tables; submitted to ApJSSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
Stellar spectral classification is a fundamental tool of modern astronomy, providing insight into physical characteristics such as effective temperature, surface gravity, and metallicity. Accurate and fast spectral typing is an integral need for large all-sky spectroscopic surveys like the SDSS and LAMOST. Here, we present the next version of PyHammer, stellar spectral classification software that uses optical spectral templates and spectral line index measurements. PyHammer v2.0 extends the classification power to include carbon (C) stars, DA white dwarf (WD) stars, and also double-lined spectroscopic binaries (SB2). This release also includes a new empirical library of luminosity-normalized spectra that can be used to flux calibrate observed spectra, or to create synthetic SB2 spectra. We have generated physically reasonable SB2 combinations as templates, adding to PyHammer the ability to spectrally type SB2s. We test classification success rates on SB2 spectra, generated from the SDSS, across a wide range of spectral types and signal-to-noise ratios. Within the defined range of pairings described, more than $95\%$ of SB2s are correctly classified.
- [16] arXiv:2006.01200 [pdf, other]
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Title: Antimatter as Macroscopic Dark MatterComments: 13 pages, 1 figureSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Experiment (hep-ex)
Antimatter macroscopic dark matter {\bob (macros)} refers to a generic {\bob class} of antimatter dark matter candidates that interact with ordinary matter primarily through annihilation with large cross-sections. A combination of terrestrial, astrophysical, and cosmological observations constrain a portion of the anti-macro parameter space. However, a large region of the parameter space remains unconstrained, most notably for nuclear-dense objects.
- [17] arXiv:2006.01224 [pdf, other]
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Title: Impact of Global Data Assimilation System atmospheric models on astroparticle showersSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
We present a methodology to simulate the impact of the Global Data Assimilation System (GDAS) atmospheric models in particle flux on detectors at the Earth's surface. To validate our methodology, we built GDAS monthly profiles over Malarg\"ue between 2006 and 2011, comparing the maximum atmospheric depth, $X_{max}$, with those calculated with the Auger atmospheric option in CORSIKA. We found that difference does not exceed 2% for both $X_{max}$. The methodology was implemented, for the city of Bucaramanga Colombia, using ARTI --a full computational framework developed by the Latin American Giant Observatory Collaboration, to estimate the signals expected at their Water Cherenkov Detectors network--. In our simulations for the year 2018, we observed that the most significant differences in the total flux, between predefined atmospheric profiles and GDAS models, occur in November and April. There also is a clear anti-correlation between the particle flux and the monthly average temperature.
- [18] arXiv:2006.01242 [pdf, other]
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Title: Outburst and Splitting of Interstellar Comet 2I/BorisovComments: 21 pages, 5 figures, 1 appendixSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
We present Hubble Space Telescope observations of a photometric outburst and splitting event in interstellar comet 2I/Borisov. The outburst, first reported with the comet outbound at 2.8 AU (Drahus et al.~2020), was caused by the expulsion of solid particles having a combined cross-section about 100 sq. km and a mass in 0.1 mm sized particles about 2e7 kg. The latter corresponds to 1e-4 of the mass of the nucleus, taken as a sphere of radius 500 m. A transient ``double nucleus'' was observed on UT 2020 March 30 (about three weeks after the outburst), having a cross-section about 0.6 sq. km and corresponding dust mass 1e5 kg. The secondary was absent in images taken on and before March 28, and in images taken on and after April 03. The unexpectedly delayed appearance and rapid disappearance of the secondary are consistent with an origin through rotational bursting of one or more large (meter-sized) boulders under the action of outgassing torques, following their ejection from the main nucleus. Overall, our observations reveal that the outburst and splitting of the nucleus are minor events involving a negligible fraction of the total mass: 2I/Borisov will survive its passage through the planetary region largely unscathed.
- [19] arXiv:2006.01248 [pdf, other]
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Title: A Symmetric Multi-rod Tunable Microwave Cavity for the HAYSTAC Dark Matter Axion SearchComments: 26 pages, 11 figuresSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Instrumentation and Detectors (physics.ins-det)
The microwave cavity experiment is the most sensitive way of looking for axions in the 0.1-10 GHz range, corresponding to masses of 0.5 - 40 $\mu$eV. The particular challenge for frequencies greater than 5 GHz is designing a cavity with a large volume that contains a resonant mode that has a high form factor, a high quality factor, a wide dynamic range, and is free from intruder modes. For HAYSTAC, we have designed and constructed an optimized high frequency cavity with a tuning mechanism that preserves a high degree of rotational symmetry, critical to maximizing its figure of merit. This cavity covers an important frequency range according to recent theoretical estimates for the axion mass, 5.5 - 7.4 GHz, and the design appears extendable to higher frequencies as well. This paper will discuss key design and construction details of the cavity, present a summary of the design evolution, and alert practitioners of potentially unfruitful avenues for future work.
- [20] arXiv:2006.01269 [pdf, ps, other]
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Title: Accretion disk luminosity for black holes surrounded by dark matterComments: 9 pages, 9 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We consider the observational properties of a static black hole space-time immersed in a dark matter envelope. We thus investigate how the modifications to geometry, induced by the presence of dark matter affect the luminosity of the black hole's accretion disk. We show that the same disk's luminosity produced by a black hole in vacuum may be produced by a smaller black hole if surrounded by dark matter under certain conditions. In particular, we demonstrate that the luminosity of the disk is markedly altered by dark matter's presence, suggesting that mass estimation of distant super-massive black holes may be changed if they are immersed in dark matter. We argue that a similar effect holds in more realistic scenarios and we discuss about the refractive index related to dark matter lensing. Hence we show how this may help explain the observed luminosity of super-massive black holes in the early universe.
- [21] arXiv:2006.01274 [pdf, ps, other]
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Title: Multiple Stellar Populations of Globular Clusters from Homogeneous Ca-CN-CH-NH Photometry. VI. M3 is not a Prototypical Normal Globular ClusterComments: Submitted to the Astrophysical Journal (19 pages, 19 figures)Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
With a new filter system that measures nitrogen abundance from NH bands, we present Ca-CN-CH-NH photometry for Galactic globular cluster (GC) M3 (NGC 5272). This cluster is one of the standard GCs, with little past attention paid to evidence for multiple populations. We present new evidence for two M3 populations with distinctly different carbon and nitrogen abundances. Our photometric indices provide reliable [C/Fe] and [N/Fe] for RGB stars, and we find that the [C/Fe] abundances (from CH indices) and [N/Fe] (from CN and NH) are very different between the two populations. There is a particularly sharp division between CN-weak and CN-strong red giants in M3, with nearly equal numbers of stars in each category. The CN-strong population shows a C-N anticorrelation that is a natural consequence of the CN cycle, while the CN-weak population shows a C-N positive relation. Furthermore, the carbon and nitrogen abundances of the CN-weak group are strongly anticorrelated with the calcium abundance, which cannot be easily understood. Additionally, the CN-weak population exhibits an elongated spatial distribution that is likely induced by its fast internal rotation, confirming our frequently observed structure-kinematic coupling in some GCs. This M3 population also show an extended and tilted RGB bump, which is most likely due to its metallicity spread that also probably produces the very large $\Delta_{C~{\rm F275W,F814W}}$ color range seen in recent HST observations of M3
- [22] arXiv:2006.01277 [pdf, other]
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Title: Four Jovian planets around low-luminosity giant stars observed by the EXPRESS and PPPSAuthors: M. I. Jones, R. Wittenmyer, C. Aguilera-Gómez, M. G. Soto, P. Torres, T. Trifonov, J. S. Jenkins, A. Zapata, P. Sarkis, O. Zakhozhay, R. Brahm, F. Santana, J. I. Vines, M. R. Díaz, M. VučkovićComments: Submitted to A&ASubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
We report the discovery of planetary companions orbiting four low-luminosity giant stars with M$_\star$ between 1.04 and 1.39 M$_\odot$. All four host stars have been independently observed by the EXoPlanets aRound Evolved StarS (EXPRESS) program and the Pan-Pacific Planet Search (PPPS). The companion signals were revealed by multi-epoch precision radial velocities obtained during nearly a decade. The planetary companions exhibit orbital periods between $\sim$ 1.2 and 7.1 years, minimum masses of m$_{\rm p}$sini $\sim$ 1.8-3.7 M$_{jup}$ and eccentricities between 0.08 and 0.42. Including these four new systems, we have detected planetary companions to 11 out of the 37 giant stars that are common targets between the EXPRESS and PPPS. After excluding four compact binaries from the common sample, we obtained a fraction of giant planets (m$_{\rm p} \gtrsim$ 1-2 M$\_{jup}$) orbiting within 5 AU from their parent star of $f = 33.3^{+9.0}_{-7.1} \%$. This fraction is significantly higher than that previously reported in the literature by different radial velocity surveys. Similarly, planet formation models under predict the fraction of gas giant around stars more massive than the Sun.
- [23] arXiv:2006.01281 [pdf]
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Title: A New Multi-Tracer Approach to Defining the Spiral arm width in the Milky WayAuthors: Jacques P ValléeComments: 23 pages MS, 7 figures, 3 tables, 33 references, 6600 words, 4 equations. Accepted for publicationsSubjects: Astrophysics of Galaxies (astro-ph.GA)
We analyze recent observations of the spiral arm width in the Milky Way, as a function of the galactic radius, and we compare this relation with the prediction from the density wave theory. We use the following method: in each spiral arm, we concentrate on the separation (or offset) between the starforming region (radio masers) near the shock front of a density wave, and the aged star region (diffuse CO gas) near the potential minimum of a density wave; we take this separation between these two tracers as the arm width.
New results: we find a typical separation (maser to diffuse CO gas) near 250 +/- 50 pc, and an increase of this separation with galactic radius of about 25 +/- 5 pc per kpc. We note that, as expected, this separation is somewhat smaller than that found earlier between the dust lane and the aged star region. Overall, these results supports the basics of a density wave. - [24] arXiv:2006.01297 [pdf, other]
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Title: Towards demystification of dust polarisation during the embedded phase of protostar formationComments: 18 pages, 12 figures plus 3 figures in the appendix, accepted for publication in A&ASubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
Measuring polarization from thermal dust emission can provide constraints on the magnetic field structure around embedded protostars. However, interpreting the observations is challenging without models that consistently account for both the complexity of the protostellar birth environment and polarization mechanisms. We aim to provide a better understanding with a focus on bridge-like structures such as that observed towards the protostellar multiple IRAS 16293--2422 by comparing synthetic polarization maps of thermal reemission with observations. We analyze the magnetic field properties associated with the formation of a protostellar multiple based on ideal MHD 3D zoom-in simulations carried out with the RAMSES code. To compare with observations, we post-process a snapshot of a bridge-like structure that is associated with a forming triple star system with the radiative transfer code POLARIS and produce multi-wavelength dust polarization maps. In the most prominent bridge of our sample, the typical density is about 10^(-16) g cm^(-3), and the magnetic field strength is about 1 to 2 mG. The magnetic field structure has an elongated toroidal morphology and the dust polarization maps trace the complex morphology. In contrast, the magnetic field strength associated with the launching of asymmetric bipolar outflows is significantly more magnetized (~100 mG). At {\lambda}=1.3 mm, the orientation of grains in the bridge is similar for the case accounting for radiative alignment torques (RATs) compared to perfect alignment with magnetic field lines. However, the polarization fraction in the bridge is three times smaller for the RAT scenario compared to assuming perfect alignment. At shorter wavelengths ({\lambda} < 200 {\mu}m), dust polarization does not trace the magnetic field because other effects such as self-scattering and dichroic extinction dominate the orientation of the polarization.
- [25] arXiv:2006.01326 [pdf, other]
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Title: From diffuse gas to dense molecular cloud coresAuthors: Javier Ballesteros-Paredes, Philippe André, Patrck Hennebelle, Ralf S. Klessen, Shu-ichiro Inutsuka, J.M. Diederik Kruijssen, Mélanie Chevance, Fumitaka Nakamura, Angela Adamo, Enrique Vázquez-SemadeniComments: 73 pages, 11 figures, preprint of a review to appear in Space Science Reviews Topical collection "Star formation". Submitted January 31st 2020; accepted May 17th 2020Subjects: Astrophysics of Galaxies (astro-ph.GA)
Molecular clouds are a fundamental ingredient of galaxies: they are the channels that transform the diffuse gas into stars. The detailed process of how they do it is not completely understood. We review the current knowledge of molecular clouds and their substructure from scales $\sim~$1~kpc down to the filament and core scale. We first review the mechanisms of cloud formation from the warm diffuse interstellar medium down to the cold and dense molecular clouds, the process of molecule formation and the role of the thermal and gravitational instabilities. We also discuss the main physical mechanisms through which clouds gather their mass, and note that all of them may have a role at various stages of the process. In order to understand the dynamics of clouds we then give a critical review of the widely used virial theorem, and its relation to the measurable properties of molecular clouds. Since these properties are the tools we have for understanding the dynamical state of clouds, we critically analyse them. We finally discuss the ubiquitous filamentary structure of molecular clouds and its connection to prestellar cores and star formation.
- [26] arXiv:2006.01337 [pdf, other]
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Title: Inference of the Local Interstellar Spectra of Cosmic Ray Nuclei Z<=28 with the GalProp-HelMod FrameworkAuthors: M. J. Boschini, S. Della Torre, M. Gervasi, D. Grandi, G. Johannesson, G. La Vacca, N. Masi, I. V. Moskalenko, S. Pensotti, T. A. Porter, L. Quadrani, P. G. Rancoita, D. Rozza, M. TacconiComments: 89 pages, 36 figures, 60 tables, submitted to ApJSSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
(Abridged) The direct precise measurements of spectra of cosmic rays (CR) species in the wide energy range form a basis for propagation models, for interpretation of gamma-ray and microwave observations, and for disentangling possible signatures of new phenomena. Composition and spectra of CR species are vital for studies of galactic nucleosynthesis and high-energy processes in variety of environments and on different scales. Since the beginning of its operation, AMS-02 has delivered outstanding quality measurements of the spectra of CR antiprotons, electrons, positrons, and nuclei: H-O, Ne, Mg, Si. However, the spectra of heavier nuclei are expected to be available only later in the mission, which is currently extended through the end of the International Space Station (ISS) in 2030. Meanwhile, a comparison of published AMS-02 results with data from earlier experiments, such as HEAO-3-C2, indicate that earlier data may be affected by significant undocumented systematic errors. This creates an awkward situation: the new data are still incomplete, while using the old data to make up for the lack of AMS-02 measurements could result in significant errors. In this paper we are using the existing AMS-02 data to test HEAO-3-C2 results. We show that a fraction of HEAO-3-C2 data match available AMS-02 measurements quite well and can be used together with Voyager 1 and ACE-CRIS data to make predictions for the local interstellar spectra (LIS) of nuclei that are not yet released by the AMS-02 collaboration. We are also updating our already published LIS to provide a complete set of LIS from H-Ni in the energy range from 1 MeV/nucleon to ~100-500 TeV/nucleon thus covering 8-9 orders of magnitude in energy. Our calculations employ the GalProp-HelMod framework that is proved to be a reliable tool in deriving the LIS of CR antiprotons, electrons, and nuclei from H to O.
- [27] arXiv:2006.01344 [pdf, ps, other]
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Title: Asymmetric distributions of H2O and SiO masers towards V627 CasAuthors: Haneul Yang, Se-Hyung Cho, Youngjoo Yun, Dong-Hwan Yoon, Dong-Jin Kim, Hyosun Kim, Sung-Chul Yoon, Richard Dodson, María J. Rioja, Hiroshi ImaiComments: 7 pages, 4 figures, 1 table, Published in MNRASJournal-ref: MNRAS, 495, 1284-1290 (2020)Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
We performed simultaneous observations of the H2O 6(1,6) - 5(2,3) (22.235080 GHz) and SiO v= 1, 2, J = 1 - 0, SiO v = 1, J = 2 - 1, 3 - 2 (43.122080, 42.820587, 86.243442, and 129.363359 GHz) masers towards the suspected D-type symbiotic star, V627 Cas, using the Korean VLBI Network. Here, we present astrometrically registered maps of the H2O and SiO v = 1, 2, J = 1 - 0, SiO v = 1, J = 2 - 1 masers for five epochs from January 2016 to June 2018. Distributions of the SiO maser spots do not show clear ring-like structures, and those of the H2O maser are biased towards the north-north-west to west with respect to the SiO maser features according to observational epochs. These asymmetric distributions of H2O and SiO masers are discussed based on two scenarios of a bipolar outflow and the presence of the hot companion, a white dwarf, in V627 Cas. We carried out ring fitting of SiO v = 1, and v = 2 masers and estimated the expected position of the cool red giant. The ring radii of the SiO v = 1 maser are slightly larger than those of the SiO v = 2 maser, as previously known. Our assumption for the physical size of the SiO maser ring of V627 Cas to be the typical size of a SiO maser ring radius (\sim4 au) of red giants yields the distance of V627 Cas to be \sim1 kpc.
- [28] arXiv:2006.01356 [pdf, other]
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Title: New Constraints On the Origin of Surface Brightness Profile Breaks of Disk Galaxies From MaNGAAuthors: Yimeng Tang, Qianhui Chen, Hong-Xin Zhang, Zesen Lin, Guangwen Chen, Yulong Gao, Zhixiong Liang, Haiyang Liu, Xu KongComments: 22 pages, 14 figures, accepted for publication in ApJSubjects: Astrophysics of Galaxies (astro-ph.GA)
In an effort to probe the origin of surface brightness profile (SBP) breaks widely observed in nearby disk galaxies, we carry out a comparative study of stellar population profiles of 635 disk galaxies selected from the MaNGA spectroscopic survey. We classify our galaxies into single exponential (TI), down-bending (TII) and up-bending (TIII) SBP types, and derive their spin parameters and radial profiles of age/metallicity-sensitive spectral features. Most TII (TIII) galaxies have down-bending (up-bending) star formation rate (SFR) radial profiles, implying that abrupt radial changes of SFR intensities contribute to the formation of both TII and TIII breaks. Nevertheless, a comparison between our galaxies and simulations suggests that stellar migration plays a significant role in weakening down-bending $\Sigma_{\star}$ profile breaks. While there is a correlation between the break strengths of SBPs and age/metallicity-sensitive spectral features for TII galaxies, no such correlation is found for TIII galaxies, indicating that stellar migration may not play a major role in shaping TIII breaks, as is evidenced by a good correspondence between break strengths of $\Sigma_{\star}$ and surface brightness profiles of TIII galaxies. We do not find evidence for galaxy spin being a relevant parameter for forming different SBP types, nor do we find significant differences between the asymmetries of galaxies with different SBP types, suggesting that environmental disturbances or satellite accretion in the recent past do not significantly influence the break formation. By dividing our sample into early and late morphological types, we find that galaxies with different SBP types follow nearly the same tight stellar mass-$R_{25}$ relation, which makes the hypothesis that stellar migration alone can transform SBP types from TII to TI and then to TIII highly unlikely.
- [29] arXiv:2006.01394 [pdf, ps, other]
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Title: a catalog rv variable star candidates from lamostAuthors: Zhijia Tian, Xiaowei Liu, Haibo Yuan, Xuan Fang, Bingqiu Chen, Maosheng Xiang, Yang Huang, Shaolan Bi, Wuming Yang, Yaqian Wu, Chun Wang, Huawei Zhang, Zhiying Huo, Yong Yang, Gaochao Liu, Jincheng Guo, Meng ZhangComments: 16 pages, 23 figures, Accepted for publication in ApJSSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
RV variable stars are important in astrophysics. The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectroscopic survey has provided ~ 6.5 million stellar spectra in its Data Release 4 (DR4). During the survey, ~ 4.7 million unique sources were targeted and ~ 1 million stars observed repeatedly. The probabilities of stars being RV variables are estimated by comparing the observed radial velocity variations with the simulated ones. We build a catalog of 80,702 RV variable candidates with probability greater than 0.60 by analyzing the duplicate-observed multi-epoch sources covered by the LAMOST DR4. Simulations and cross-identifications show that the purity of the catalog is higher than 80%. The catalog consists of 77% binary systems and 7% pulsating stars as well as 16% pollution by single stars. 3,138 RV variables are classified through cross-identifications with published results in literatures. By using the 3,138 sources common to both LAMOST and a collection of published RV variable catalogs we are able to analyze LAMOST's RV variable detection rate. The efficiency of the method adopted in this work relies not only on the sampling frequency of observations but also periods and amplitudes of RV variables. With the progress of LAMOST, Gaia and other surveys, more and more RV variables would will be confirmed and classified. This catalog is valuable for other large-scale surveys, especially for RV variable searches. The catalog will be released according to the LAMOST Data Policy via this http URL
- [30] arXiv:2006.01407 [pdf, other]
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Title: HIR4: Cosmological signatures imprinted on the cross correlation between 21cm map and galaxy clusteringAuthors: Feng Shi, Yong-Seon Song, Jacobo Asorey, David Parkinson, Kyungjin Ahn, Jian Yao, Le Zhang, Shifan ZuoComments: 14 pages, 10 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We explore the cosmological multi-tracer synergies between a DESI-like Emission Line Galaxy (ELG) distribution and a Tianlai-like 21cm intensity map. We use simulated maps generated from a particle simulation in the light-cone volume (Horizon Run 4), sky-trimmed and including the effects of foreground contamination, its removal, and instrument noise. We first validate how the foreground residual affects the recovered 21cm signal by putting different levels of foreground contamination into the 21cm maps. We find that the contamination cannot be ignored in the angular auto-power spectra of HI even when it is small, but has no influence on the accuracy of the angular cross-power spectra between HI and galaxies. In the foreground-cleaned map case, as information is lost in the cleaning procedure, there is also a bias in the cross-power spectrum. However, we found that the bias from the cross-power spectrum is scale-independent, which is easily parameterised as part of the model, while the offset in the HI auto-power spectrum is non-linear. In particular, we tested that the cross power also benefits from the cancellation of the bias in the power spectrum measurement that is induced by the instrument noise, which changes the shape of the auto-power spectra but leaves the cross-power unaffected. We then modelled the angular cross-power spectra to fit the BAO feature in broadband shape of the angular cross power spectrum, including contamination from the residual foreground and the effect of instrument noise. We forecast a constraint on the angular diameter distance $D_\mathrm{A}$ for the Tianlai Pathfinder redshift $0.775<z<1.03$, giving a distance measurement with a precision of 3.3% at that redshift.
- [31] arXiv:2006.01438 [pdf, other]
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Title: Learning to do multiframe blind deconvolution unsupervisedlyAuthors: A. Asensio Ramos (IAC)Comments: 11 pages, 8 figures, submitted to A&ASubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Computer Vision and Pattern Recognition (cs.CV)
Observation from ground based telescopes are affected by the presence of the Earth atmosphere, which severely perturbs them. The use of adaptive optics techniques has allowed us to partly beat this limitation. However, image selection or post-facto image reconstruction methods are routinely needed to reach the diffraction limit of telescopes. Deep learning has been recently used to accelerate these image reconstructions. Currently, these deep neural networks are trained with supervision, so that standard deconvolution algorithms need to be applied a-priori to generate the training sets. Our aim is to propose an unsupervised method which can then be trained simply with observations and check it with data from the FastCam instrument. We use a neural model composed of three neural networks that are trained end-to-end by leveraging the linear image formation theory to construct a physically-motivated loss function. The analysis of the trained neural model shows that multiframe blind deconvolution can be trained self-supervisedly, i.e., using only observations. The output of the network are the corrected images and also estimations of the instantaneous wavefronts. The network model is of the order of 1000 times faster than applying standard deconvolution based on optimization. With some work, the model can bed used on real-time at the telescope.
- [32] arXiv:2006.01450 [pdf, other]
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Title: Cosmological parameter estimation for dynamical dark energy models with future fast radio burst observationsComments: 10 pages, 6 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
Fast radio bursts (FRBs) are a mysterious astrophysical phenomenon of bright pulses emitted at radio frequencies, and it is expected for them to be frequently detected in the future. The dispersion measures of FRBs are related to cosmological parameters, and thus FRBs have a potential to be developed into a new cosmological probe if their data can be largely accumulated in the future. In this work, we study the capability of future FRB data for improving cosmological parameter estimation in two dynamical dark energy models. We find that the simulated FRB data can break the parameter degeneracies inherent in the current cosmic microwave background (CMB) data. Therefore, the combination of the CMB and FRB data can significantly improve the constraints on the Hubble constant and dark energy parameters, compared to those using CMB or FRB alone. If ten thousand events of FRBs with known redshifts are detected in the future, they would behave better than the baryon acoustic oscillation (BAO) data in breaking the parameter degeneracies inherent in the CMB data. We also find that the combination of FRB and gravitational wave (GW) standard siren data provides an independent low-redshift probe to verify the results from CMB and BAO data. For the data combination of CMB, GW, and FRB, it is found that the main contribution to the constraints comes from the CMB and GW data, but the inclusion of FRB data still can evidently improve the constraint on the baryon density.
- [33] arXiv:2006.01453 [pdf, other]
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Title: Developement of a stabilized Fabry-Perot etalon based calibrator for Hanle Echelle Spectrograph (HESP)Comments: Accepted in Applied Optics. 9 pages, 19 figuresSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
Accurate wavelength calibration is an important factor for any measurement with high resolution spectrographs. Stellar spectrum comprises of discrete absorption or emission lines whose position is precisely determined by calibrating the spectrograph using known reference lines generated from laboratory sources. For the spectrograph to measure small variations in Doppler shift, the wavelength calibration must be sufficiently stable during observation time. Instrument instability, mainly due to environmental factors like temperature and pressure variations, limitations of traditional calibration methods, for example Th-Ar lamps, are the main challenges which high precision spectroscopy. Through proper environmental control, by maintaining pressure at few mbar and temperature fluctuations within $\pm$0.05$^{\circ}$C, Fabry P\'erot etalon (FP) can yield a velocity precision of 1-10 m/s, when used for wavelength calibration. We have developed a passively stabilized FP based wavelength calibrator for Hanle Echelle Spectrograph (HESP) installed on Himalayan Chandra Telescope (HCT) at Indian Astronomical Observatory (IAO), Hanle, India. The etalon has been characterized using Fourier Transform Spectrograph (FTS) and initial test runs have been performed with HESP. In this paper we present the design and construction of the instrument along with preliminary test results obtained from HESP.
- [34] arXiv:2006.01467 [pdf, ps, other]
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Title: Masses of the components of SB2 binaries observed with Gaia. V. Accurate SB2 orbits for 10 binaries and masses of the components of 5 binariesAuthors: Jean-Louis Halbwachs, Flavien Kiefer, Yveline Lebreton, Henri M.J. Boffin, Frédéric Arenou, Jean-Baptiste Le Bouquin, Benoît Famaey, Dimitri Pourbaix, Patrick Guillout, Jean-Baptiste Salomon, Tsevi MazehComments: 16 pages, 7 figures and 10 others attached files; to be published in MNRASSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
Double-lined spectroscopic binaries (SB2s) are one of the main sources of stellar masses, as additional observations are only needed to give the inclinations of the orbital planes in order to obtain the individual masses of the components. For this reason, we are observing a selection of SB2s using the SOPHIE spectrograph at the Haute-Provence observatory in order to precisely determine their orbital elements. Our objective is to finally obtain masses with an accuracy of the order of one percent by combining our radial velocity (RV) measurements and the astrometric measurements that will come from the Gaia satellite. We present here the RVs and the re-determined orbits of 10 SB2s. In order to verify the masses we will derive from Gaia, we obtained interferometric measurements of the ESO VLTI for one of these SB2s. Adding the interferometric or speckle measurements already published by us or by others for 4 other stars, we finally obtain the masses of the components of 5 binary stars, with masses ranging from 0.51 to 2.2 solar masses, including main-sequence dwarfs and some more evolved stars whose location in the HR diagram has been estimated.
- [35] arXiv:2006.01509 [pdf, other]
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Title: Detection of gravitational-wave signals from binary neutron star mergers using machine learningAuthors: Marlin B. Schäfer (1 and 2), Frank Ohme (1 and 2), Alexander H. Nitz (1 and 2) ((1) Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), (2) Leibniz Universität Hannover)Comments: 14 pages, 6 figures, 1 table, supplemental materials at this https URLSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM); Machine Learning (cs.LG); General Relativity and Quantum Cosmology (gr-qc)
As two neutron stars merge, they emit gravitational waves that can potentially be detected by earth bound detectors. Matched-filtering based algorithms have traditionally been used to extract quiet signals embedded in noise. We introduce a novel neural-network based machine learning algorithm that uses time series strain data from gravitational-wave detectors to detect signals from non-spinning binary neutron star mergers. For the Advanced LIGO design sensitivity, our network has an average sensitive distance of 130 Mpc at a false-alarm rate of 10 per month. Compared to other state-of-the-art machine learning algorithms, we find an improvement by a factor of 6 in sensitivity to signals with signal-to-noise ratio below 25. However, this approach is not yet competitive with traditional matched-filtering based methods. A conservative estimate indicates that our algorithm introduces on average 10.2 s of latency between signal arrival and generating an alert. We give an exact description of our testing procedure, which can not only be applied to machine learning based algorithms but all other search algorithms as well. We thereby improve the ability to compare machine learning and classical searches.
- [36] arXiv:2006.01518 [pdf, other]
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Title: AT 2017gbl: a dust obscured TDE candidate in a luminous infrared galaxyAuthors: E. C. Kool, T. M. Reynolds, S. Mattila, E. Kankare, M. A. Perez-Torres, A. Efstathiou, S. Ryder, C. Romero-Canizales, W. Lu, T. Heikkila, G. E. Anderson, M. Berton, J. Bright, G. Cannizzaro, D. Eappachen, M. Fraser, M. Gromadzki, P. G. Jonker, H. Kuncarayakti, P. Lundqvist, K. Maeda, R. M. McDermid, A. M. Medling, S. Moran, A. Reguitti, M. Shahbandeh, S. Tsygankov, V. U, T. WeversComments: Revised manuscript submitted to MNRAS. 32 pages, 22 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)
We present the discovery with Keck of the extremely infrared (IR) luminous transient AT 2017gbl, coincident with the Northern nucleus of the luminous infrared galaxy (LIRG) IRAS 23436+5257. Our extensive multi-wavelength follow-up spans ~900 days, including photometry and spectroscopy in the optical and IR, and (very long baseline interferometry) radio and X-ray observations. Radiative transfer modelling of the host galaxy spectral energy distribution shows the presence of a hitherto undetected dust obscured active galactic nucleus (AGN). The optical and near-IR spectra show broad 2000 km/s hydrogen, He I and O I emission features that decrease in flux over time. Radio imaging shows a fast evolving compact source of synchrotron emission spatially coincident with AT 2017gbl. We infer a lower limit for the radiated energy of 7.3 x 10^50 erg from the IR photometry. An extremely energetic supernova would satisfy this budget, but is ruled out by the radio counterpart evolution. Instead, we propose AT 2017gbl is related to an accretion event by the central supermassive black hole, where the spectral signatures originate in the AGN broad line region and the IR photometry is consistent with re-radiation by polar dust. Given the fast evolution of AT 2017gbl, we deem a tidal disruption event (TDE) of a star a more plausible scenario than a dramatic change in the AGN accretion rate. This makes AT 2017gbl the third TDE candidate to be hosted by a LIRG, in contrast to the so far considered TDE population discovered at optical wavelengths and hosted preferably by post-starburst galaxies.
- [37] arXiv:2006.01543 [pdf, other]
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Title: A Bayesian Approach to Modelling Multi-Messenger Emission from Blazars using Lepto-Hadronic Kinetic EquationsComments: 26 pages, 19 figures, submitted to MNRAS, under reviewSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Abstract Blazar TXS 0506+056 is the main candidate for a coincident neutrino and gamma-ray flare event. In this paper, we compose a detailed kinetic lepto-hadronic emission model capable of producing a photon and neutrino spectrum given a set of parameters. Our model includes a range of large-scale geometries and both dynamical and steady-state injection models for electrons and protons. We link this model with a Markov Chain Monte Carlo sampler to obtain a powerful statistical tool that allows us to both fit the Spectral Energy Distribution and study the probability density functions and correlations of the parameters. Assuming a fiducial neutrino flux, we demonstrate how multi-messenger observations can be modelled jointly in a Bayesian framework. We find the best parameters for each of the variants of the model tested and report on their cross-correlations. Additionally, we confirm that reproducing the neutrino flux of TXS 0506+056 requires an extreme proton to electron ratio either in the local acceleration process or from external injection.
- [38] arXiv:2006.01549 [pdf, other]
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Title: ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- I. Survey description and a first look at G9.62+0.19Authors: Tie Liu, Neal J. Evans, Kee-Tae Kim, Paul F. Goldsmith, Sheng-Yuan Liu, Qizhou Zhang, Kenichi Tatematsu, Ke Wang, Mika Juvela, Leonardo Bronfman, Maria. R. Cunningham, Guido Garay, Tomoya Hirota, Jeong-Eun Lee, Sung-Ju Kang, Di Li, Pak-Shing Li, Diego Mardones, Sheng-Li Qin, Isabelle Ristorcelli, Anandmayee Tej, L. Viktor Toth, Jing-Wen Wu, Yue-Fang Wu, Hee-weon Yi, Hyeong-Sik Yun, Hong-Li Liu, Ya-Ping Peng, Juan Li, Shang-Huo Li, Chang-Won Lee, Zhi-Qiang Shen, Tapas Baug, Jun-Zhi Wang, Yong Zhang, Namitha Issac, Feng-Yao Zhu, Qiu-Yi Luo, Archana Soam, Xun-Chuan Liu, Feng-Wei Xu, Yu Wang, Chao Zhang, Zhiyuan Ren, Chao ZhangComments: Accepted to MNRAS; The paper II is arXiv:2005.12080Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
The "ATOMS," standing for {\it ALMA Three-millimeter Observations of Massive Star-forming regions}, survey has observed 146 active star forming regions with ALMA Band 3, aiming to systematically investigate the spatial distribution of various dense gas tracers in a large sample of Galactic massive clumps, to study the roles of stellar feedback in star formation, and to characterize filamentary structures inside massive clumps. In this work, the observations, data analysis, and example science of the "ATOMS" survey are presented, using a case study for the G9.62+0.19 complex. Toward this source, some transitions, commonly assumed to trace dense gas, including CS $J = 2-1$, HCO$^+$ $J = 1-0$ and HCN $J = 1-0$, are found to show extended gas emission in low density regions within the clump; less than 25\% of their emission is from dense cores. SO, CH$_3$OH, H$^{13}$CN and HC$_3$N show similar morphologies in their spatial distributions and reveal well the dense cores. Widespread narrow SiO emission is present (over $\sim$1 pc), which may be caused by slow shocks from large--scale colliding flows or H{\sc ii} regions. Stellar feedback from an expanding H{\sc ii} region has greatly reshaped the natal clump, significantly changed the spatial distribution of gas, and may also account for the sequential high-mass star formation in the G9.62+0.19 complex. The ATOMS survey data can be jointly analyzed with other survey data, e.g., "MALT90", "Orion B", "EMPIRE", "ALMA\_IMF", and "ALMAGAL", to deepen our understandings of "dense gas" star formation scaling relations and massive proto-cluster formation.
- [39] arXiv:2006.01552 [pdf, ps, other]
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Title: Periodically-repeating fast radio bursts: Lense-Thirring precession of a debris disk?Authors: Wen-Cong ChenComments: 6 pages, 2 figures, PASJ in pressSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Recently, repeating fast radio bursts (FRBs) with a period of $P_{\rm FRB}=16.35\pm0.18$ days from FRB 180916.J0158+65 had been reported. It still remains controversial how to give rise to such a periodicity of this FRB. In this Letter, based on an assumption of a young pulsar surrounding by a debris disk, we attempt to diagnose whether the Lense-Thirring precession of the disk on the emitter can produce the observed periodicity. Our calculations indicate that the Lense-Thirring effect of a tilted disk can result in a precession period of 16 days for a mass inflow rate of $0.5-1.5\times10^{18}~\rm g\,s^{-1}$, a spin period of 1-20 ms of the pulsar, and an extremely low viscous parameter $\alpha=10^{-8}$ in the disk. The disk mass and the magnetic field of the pulsar are also constrained to be $\sim10^{-3}~\rm M_{\odot}$ and $< 2.5\times 10^{13}~\rm G$. In our model, a new born pulsar with normal magnetic field and millisecond period would successively experience accretion phase, propeller phase, and is visible as a strong radio source in the current stage. The rotational energy of such a young NS can provide the observed radio bursting luminosity for $400$ years.
- [40] arXiv:2006.01583 [pdf]
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Title: Estimation of the Total Mass of 10 Exoplanets and their Host Stars Based on the Primary Transit MethodAuthors: A. Poro, M. Hedayatjoo, Y. Dashti, F. MohammadiZadeh, M. Hashemi, E. Rajaei, A. Kazemi, A. Sarostad, M. Nastaran, Z. Zarei, A. Dehghani GhanatghestaniComments: Submitted tO Journal of Occultation and Eclipse (JOE) ISSN 2522-7955Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
In this study, ten exoplanets were studied. Their photometric observations were obtained from the ETD. After performing the data reduction steps, their parameters were obtained through Exofast online software. Then the total mass of the exoplanets and the host stars were obtained through a software that was mentioned in this study. The location of the host stars in this study was also plotted in the H-R diagram.
- [41] arXiv:2006.01587 [pdf]
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Title: Period Study by the Transit Method with Ground-Based ObservationsAuthors: A. Poro, F. Elmi Kanklou, S. Ranjbaryan Iri Olya, N. Dashan, F. Ansarinia, F. Abdollahi, A. Haselpour, F. Dehghanizadeh Baghdadabad, F. Jahediparizi, A. Gardi, A. Hossein vandComments: Submitted to Journal of Occultation and Eclipse (JOE) ISSN 2522-7955Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
In this study, 19 exoplanets were studied. Their photometric observations were obtained from the ETD. After performing the data reduction steps, its parameters were obtained through Exofast online software. Then calculated orbital parameters of planets and as a result, the periods of all the planets in this study match comparable with the Extrasolar Planets Encyclopedia. Also, we present Tc and Tdepth obtained from the observations. The location of the host stars in this study was also plotted in the H-R diagram.
- [42] arXiv:2006.01591 [pdf]
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Title: Radius Study of Ten Transiting Hot Jupiter Exoplanets with Ground-Based ObservationsAuthors: F. Davoudi, A. Poro, E. Paki, P. Mirshafie, F. Ahangarani, A. Farahani, M. Roshana, F. Abolhasani, Sh. Zamanpour, E. Lashgari, S. Modarres, A. MohandesComments: 10 PagesSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
In this research, 14 light curves of 10 hot Jupiter exoplanets available on Exoplanet Transit Database (ETD) were analyzed. We extracted the transit parameters using EXOFAST software. Finally, we compared the planet's radius parameter calculated by the EXOFAST with the value at the NASA Exoplanet Archive (NEA) using the confidence interval method. According to the results obtained from this comparison, there is an acceptable match for the planet's radius with NEA values. Also, based on the average value of 350 mm optics in this study, it shows that the results obtained using small telescopes can be very significant if there is appropriate observational skill to study more discovered planets.
- [43] arXiv:2006.01596 [pdf]
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Title: Practical Studies for Different Methods of Lunar Occultation Timing with DSLR CamerasComments: Submitted to Journal of Occultation and Eclipse (JOE) ISSN 2522-7955Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
There are several methods for timing occultations. Many astronomers may not have access to standard video timing tools, but many of them have access to digital single-lens reflex (DSLR) cameras. In order to increase the accuracy of timing, creative methods were investigated for the DSLR camera technique. These can be a good substitute for the less accurate visual timing method. Two methods of continuous shooting and afocal filming were examined in the experimental phase, which was calculated using maximum speed sequential photography 5 shots per second, 0.1 seconds precision and 60 frames per second shooting speed resulting in 0.0083 seconds precision timing. Two different sources of time were used for video timing: Internet clock and GPS, where GPS base results were more accurate than the Internet clock.
- [44] arXiv:2006.01643 [pdf, other]
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Title: New Analytic Solutions for Galaxy Evolution II: Wind Recycling, Galactic Fountains and Late-Type GalaxiesAuthors: A. Lapi (1,2,3,4), L. Pantoni (1,3), L. Boco (1,2,3), L. Danese (1,2) ((1) SISSA, Trieste, Italy, (2) IFPU, Trieste, Italy, (3) INFN/TS, Trieste, Italy, (4) INAF/OATS, Trieste, Italy)Comments: 33 pages, 15 figures. Accepted by ApJ. arXiv admin note: substantial text overlap with arXiv:1906.07458Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We generalize the analytic solutions presented in Pantoni et al. (2019) by including a simple yet effective description of wind recycling and galactic fountains, with the aim of self-consistently investigating the spatially-averaged time evolution of the gas, stellar, metal, and dust content in disc-dominated late-type galaxies (LTGs). Our analytic solutions, when supplemented with specific prescriptions for parameter setting and with halo accretion rates from $N-$body simulations, can be exploited to reproduce the main statistical relationships followed by local LTGs; these involve, as a function of the stellar mass, the star formation efficiency, the gas mass fraction, the gas/stellar metallicity, the dust mass, the star formation rate, the specific angular momentum, and the overall mass/metal budget. Our analytic solutions allow to easily disentangle the diverse role of the main physical processes ruling galaxy formation in LTGs; in particular, we highlight the crucial relevance of wind recycling and galactic fountains in efficiently refurnishing the gas mass, extending the star-formation timescale, and boosting the metal enrichment in gas and stars. All in all, our analytic solutions constitute a transparent, handy, and fast tool that can provide a basis for improving the (subgrid) physical recipes presently implemented in more sophisticated semi-analytic models and numerical simulations, and can offer a benchmark for interpreting and forecasting current and future spatially-averaged observations of local and higher redshift LTGs.
- [45] arXiv:2006.01646 [pdf, other]
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Title: Constraining modified gravity from tidal phenomena in binary starsComments: 16 pagesSubjects: Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
In beyond-Horndeski theories of gravity, the Vainshtein screening mechanism might only be partially effective inside stellar objects. This results in a modification of the pressure balance equation inside stars, often characterized by a single parameter ($\Upsilon$) in isotropic systems. We show how to constrain such theories of modified gravity, using tidal effects. We study such effects in cataclysmic variable star binaries and numerically obtain limits on the critical masses of the donor stars, below which they are tidally disrupted, by modeling them in beyond-Horndeski theories. This is contrasted with values of the donor masses, obtained using existing observational data, by a Monte Carlo error progression method. A best fit scenario of the two yields a parametric constraint in the theories that we consider, within the approximations used. Here, we obtain the allowed range $ 0 \le \Upsilon \le 0.47 $.
- [46] arXiv:2006.01655 [pdf, ps, other]
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Title: Hot Subdwarf Stars Identified in Gaia DR2 with Spectra of LAMOST DR6 and DR7. II. KinematicsComments: 15 pages, 6 figures, accepted for publication in APJ. arXiv admin note: substantial text overlap with arXiv:1906.09393Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
Combining the LAMOST radial velocities with Gaia parallaxes and proper motions, we presented 3D Galactic space motions and the orbits of 182 single-lined hot subdwarf stars. These stars have been identified by Lei et al. (2020) in Gaia DR2 with LAMOST DR6 and DR7 spectra. He-rich hot subdwarf stars with log(y)>0 show the largest standard deviations of the Galactic velocity components and orbital parameters, while those with -1<log(y)<0 exhibit the second largest standard deviations. The two groups of He-deficient stars with log(y)<-1 show similar standard deviations, which is systematically lower compared to He-rich stars. We also presented a kinematic population classification of the four hot subdwarf helium groups based on their positions in the U-V velocity diagram, J_z-eccentricity diagram and their Galactic orbits. The overall tendency of the fractional distributions of the four hot subdwarf helium groups in the halo, thin disk and thick disk is largely consistent with the findings reported by Luo et al.(2019) based on LAMOST DR5, which appears to support the predictions of binary population synthesis (Han et al. 2003; 2008). He-deficient stars with -2.2<log(y)<-1 likely origin from stable the Roche lobe overflow channel, He-deficient stars with log(y)<-2.2 from the common envelope ejection channel, and He-rich stars with log(y)>0 from the merger channel of double He white dwarf stars. The fraction of He-rich hot subdwarf stars with -1<log(y)<0 in the thin disk and the halo are far higher than in the thick disk, which implies that these stars have different formation channels in the thin disk and in the halo.
- [47] arXiv:2006.01684 [pdf, other]
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Title: The CARMENES search for exoplanets around M dwarfs. Measuring precise radial velocities in the near infrared: the example of the super-Earth CD Cet bAuthors: F. F. Bauer, M. Zechmeister, A. Kaminski, C. Rodríguez López, J. A. Caballero, M. Azzaro, O. Stahl, D. Kossakowski, A. Quirrenbach, S. Becerril Jarque, E. Rodríguez, P. J. Amado, W. Seifert, A. Reiners, S. Schäfer, I. Ribas, V. J. S. Béjar, M. Cortés-Contreras, S. Dreizler, A. Hatzes, T. Henning, S. V. Jeffers, M. Kürster, M. Lafarga, D. Montes, J. C. Morales, J. H. M. M. Schmitt, A. Schweitzer, E. SolanoSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR)
The high-resolution, dual channel, visible and near-infrared spectrograph CARMENES offers exciting opportunities for stellar and exoplanetary research on M dwarfs. In this work we address the challenge of reaching the highest radial velocity precision possible with a complex, actively cooled, cryogenic instrument, such as the near-infrared channel. We describe the performance of the instrument and the work flow used to derive precise Doppler measurements from the spectra. The capability of both CARMENES channels to detect small exoplanets is demonstrated with the example of the nearby M5.0 V star CD Cet (GJ 1057), around which we announce a super-Earth ($4.0\pm0.4\,M_\oplus$) companion on a 2.29 d orbit.
- [48] arXiv:2006.01690 [pdf, other]
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Title: The Milky Way's cluster age function in light of Gaia DR2Authors: Friedrich Anders, Tristan Cantat-Gaudin, Irene Quadrino-Lodoso, Carme Jordi, Mark Gieles, Alfred Castro-Ginard, Lola Balaguer-NúñezComments: 4 pages, 2 figures, submitted to A&A Letters. Notebooks including supplementary analysis here: this https URLSubjects: Astrophysics of Galaxies (astro-ph.GA)
We perform a systematic reanalysis of the age distribution of Galactic open star clusters. Using a catalogue of homogeneously determined ages for 834 open clusters contained in a 2 kpc cylinder around the Sun and characterised with astrometric and photometric data from the Gaia satellite, we find that it is necessary to revise earlier works that relied on data from the Milky Way Star Cluster survey. After establishing age-dependent completeness limits for our sample, we find that the cluster age function in the range $6.5 < \log t<10$ is compatible with a Schechter-type or broken power-law function, whose parameters we determine by MCMC fitting. Our best-fit values indicate an earlier drop of the age function (by a factor of $2-3$) with respect to the results obtained in the last five years, and are instead more compatible with results obtained in the early 2000s and radio observations of inner-disc clusters. Furthermore, we find excellent agreement with the dynamical cluster formation and destruction models of Lamers et al. (2005), indicating a typical destruction time-scale of $\sim1.5$ Gyr for a $10^4\, {\rm M}_{\odot}$ cluster and a present-day cluster-formation rate of $\sim 0.6\pm 0.1$ Myr$^{-1}$kpc$^{-2}$, suggesting that only $8-15\, \%$ of all stars born in the solar neighbourhood form in bound clusters. Accurate cluster-mass measurements are now needed to place more precise constraints on open-cluster formation and evolution models.
- [49] arXiv:2006.01697 [pdf, other]
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Title: The Last Journey. I. An Extreme-Scale Simulation on the Mira SupercomputerAuthors: Katrin Heitmann, Nicholas Frontiere, Esteban Rangel, Patricia Larsen, Adrian Pope, Imran Sultan, Thomas Uram, Salman Habib, Hal Finkel, Danila Korytov, Eve Kovacs, Silvio Rizzi, Joe InsleyComments: 12 pages, 8 figures. Submitted to ApJS. The Last Journey data products can be accessed here: this https URLSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The Last Journey is a large-volume, gravity-only, cosmological N-body simulation evolving more than 1.24 trillion particles in a periodic box with a side-length of 5.025Gpc. It was implemented using the HACC simulation and analysis framework on the BG/Q system, Mira. The cosmological parameters are chosen to be consistent with the results from the Planck satellite. A range of analysis tools have been run in situ to enable a diverse set of science projects, and at the same time, to keep the resulting data amount manageable. Analysis outputs have been generated starting at redshift z~10 to allow for construction of synthetic galaxy catalogs using a semi-analytic modeling approach in post-processing. As part of our in situ analysis pipeline we employ a new method for tracking halo sub-structures, introducing the concept of subhalo cores. The production of multi-wavelength synthetic sky maps is facilitated by generating particle lightcones in situ, also beginning at z~10. We provide an overview of the simulation set-up and the generated data products; a first set of analysis results is presented. A subset of the data is publicly available.
- [50] arXiv:2006.01700 [pdf, other]
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Title: Radio morphology of southern narrow-line Seyfert 1 galaxies with the JVLA observationsAuthors: S. Chen, E. Jarvela, L. Crepaldi, M. Zhou, S. Ciroi, M. Berton, P. Kharb, L. Foschini, M. Gu, G. La Mura, A. VietriComments: Submitted to MNRAS, 24 pages, 65 figures, 3 tablesSubjects: Astrophysics of Galaxies (astro-ph.GA)
We present the results of new radio observations carried out with the Karl G. Jansky Very Large Array C-configuration at 5.5 GHz for a sample of southern narrow-line Seyfert 1 galaxies (NLS1s). This work increases the number of known radio-detected NLS1s in the southern hemisphere, and confirms that the radio emission of NLS1s is mainly concentrated in a central region at kpc-scale and only a few sources show diffuse emission. In RQ NLS1s, the radio luminosity tends to be higher in steep-spectrum sources and be lower in flat-spectrum sources, which is opposite to RL NLS1s. This may be because the radio emission of steep NLS1s is dominated by misaligned jets, AGN-driven outflows, or star formation superposing on a compact core. Instead the radio emission of flat NLS1s may be produced by a central core which has not yet developed radio jets and outflows. We discover new NLS1s harboring kpc-scale radio jets and confirm that a powerful jet does not require a large-mass black hole to be generated. We also find sources dominated by star formation. These NLS1s could be new candidates in investigating the radio emission of different mechanisms.
- [51] arXiv:2006.01711 [pdf, ps, other]
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Title: Theoretical Studies of Comets in the 55 Cancri SystemComments: Accepted by MNRAS; 9 pages incl. 9 figures, 5 tablesSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
We present orbital integrations for various Jupiter family comets (JFCs) in the 55 Cancri system. This star is known to possess (at least) five planets with masses ranging from super-Earth to Jupiter-type. Furthermore, according to observational constraints, there is a space without planets between ~0.8 au and ~5.7 au, offering the principal possibility of habitable terrestrial planets, including long-term orbital stability. Hence, there is a stark motivation for the study of comets in the 55 Cnc system noting that comets are viewed a viable candidate mechanism for the delivery of water to Earth-type planets located in stellar habitable zones. However, our study shows that the duration of stability of JFC analogs in the 55 Cnc system is much shorter compared to comets in the Solar System owing to profound differences in the planetary structure of the systems. For example, between planet 55 Cnc-f and 55~Cnc-d, the comets do not undergo close cometary encounters akin to Earth and Mars in the Solar System as the planetary masses in the 55 Cnc system are much larger than in the Solar System and therefore the comets are much less orbitally stable. Nevertheless, we expect an increased number of comet-planet encounters as well as cometary collisions in the 0.8 / 5.7 au gap. Future observations and additional theoretical studies are required to shed light on the possibility of habitable terrestrial planets in the 55 Cnc system, including the possible role(s) of exocomets in the facilitation of planetary habitability.
- [52] arXiv:2006.01717 [pdf, other]
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Title: Simulating the inflation of bubbles by late jets in core collapse supernova ejectaComments: Will be submitted in two days to allow comments by readersSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We conducted three-dimensional hydrodynamical simulations to study the interaction of two late opposite jets with the ejecta of a core collapse supernova (CCSN), and study the bipolar structure that results from this interaction as the jets inflate hot-low-density bubbles. The newly born central object, a neutron star (NS; or a black hole), launches these jets at about 50 to 100 days after explosion. The bubbles cross the photosphere in the polar directions at much earlier times than the regions at the same radii near the equatorial plane. The hot bubbles releases more radiation and the photosphere recedes more rapidly in the tenuous bubble. Our results strengthen earlier claims that were based on toy models that such an interaction might lead to a late peak in the light curve, and that an equatorial observer might see a rapid drop in the light curve. Our results have implications to much earlier jets that explode the star, either jets that the newly born NS launches in a CCSN, or jets that a NS companion that merges with the core of a massive star launches in a common envelope jets supernova (CEJSN) event. Our results add indirect support to the CEJSN scenario for fast blue optical transients, e.g., AT2018cow, ZTF18abvkwla, and CSS161010.
- [53] arXiv:2006.01721 [pdf, other]
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Title: A search for young exoplanets in Sectors 1-5 of the TESS Full-Frame-ImagesComments: 22 pages, 21 figures, accepted for publication in MNRASSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR)
Young (<1Gyr) exoplanets represent a critically important area of exoplanet research, as they offer the opportunity to learn about the formation and early dynamic history of exoplanetary systems. However, finding young exoplanets is significantly complicated by the fast rotation and complex activity of their young host stars, which are often not well handled by state-of-the-art automatic pipelines. This work presents an alternative LOWESS-based pipeline focused specifically on detrending young stellar light-curves from the 30min-cadence Full Frame Images (FFIs) produced by the Transiting Exoplanet Survey Satellite ($TESS$), and includes improvements such as automatic peak-cutting of stellar variability and interpolation over masked transits to improve periodogram visibility and returned transit shapes. This work presents the details of the developed pipeline, along with initial results from its application to young stars within stellar associations in sectors 1-5 of the $TESS$ data. While no new exoplanet candidate signals were found in this work, interesting results included the recovery of all known 2min TOIs around young stars in sectors 1-5 from 30min data alone, the recovery of the young exoplanet DS Tuc Ab, a number of young eclipsing binaries and a wide array of interesting rotation. A sensitivity analysis was also undertaken for each star, showing how recovery of injected planets varied with both depth and period for each individual target. Challenges for future searches for young exoplanets are discussed, the largest being stellar rotation with periods less than 1 day and a lack of a large sample of confirmed young stars.
- [54] arXiv:2006.01723 [pdf, other]
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Title: Birth Sites of Young Stellar Associations: Recent Star Formation in a Flocculent Corrugated DiskAuthors: Alice C. Quillen, Alex R. Pettitt, Sukanya Chakrabarti, Yifan Zhang, Jonathan Gagné, Ivan MinchevSubjects: Astrophysics of Galaxies (astro-ph.GA)
With backwards orbit integration we estimate birth locations of young stellar associations and moving groups identified in the solar neighborhood that are younger than 70 Myr. The birth locations of most of these stellar associations are at smaller galactocentric radius than the Sun, implying that their stars moved radially outwards after birth. Exceptions to this rule include are the Argus and Octans associations which formed outside the Sun's Galactocentric radius. Variations in birth heights of the stellar associations suggest that they were born in a corrugated disk of molecular clouds, similar to that inferred from the current filamentary molecular cloud distribution and dust extinction maps. Multiple spiral arm features with different but near corotation pattern speeds and at different heights could account for the stellar association birth sites. We find that the young stellar associations are located in between peaks in the UV stellar velocity distribution for stars in the solar neighborhood. This would be expected if they were born in a spiral arm which perturbs stellar orbits that cross it. In contrast, stellar associations seem to be located near peaks in the vertical phase space distribution, suggesting that the gas in which stellar associations are born moves vertically together with the low velocity dispersion disk stars.
- [55] arXiv:2006.01735 [pdf, other]
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Title: A Catalog of Holes and Shells in the Interstellar Medium of the LITTLE THINGS Dwarf GalaxiesComments: 17 figures, 41 tablesSubjects: Astrophysics of Galaxies (astro-ph.GA)
We present a catalog of holes and shells in the neutral atomic hydrogen (\HI) of 41 gas-rich dwarf galaxies in LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The \HI Nearby Galaxy Survey). We analyzed their properties as part of an investigation into the relation between star formation and structures and kinematics in the \HI of small galaxies. We confirmed 306 holes between 38 pc (our resolution limit) and 2.3 kpc, with expansion velocities up to 30 \kms. The global star formation rates measured by \Ha and FUV emission are consistent with those estimated from the energy required to create the cataloged holes in our sample. Although we found no obvious correlation between global star-formation rates and the \HI surface and volume porosities of our sample, two of the four lowest porosity galaxies and the two highest porosity galaxies have no recent star formation as measured by \Ha and FUV emission.
- [56] arXiv:2006.01750 [pdf, other]
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Title: The gas production of 14 species from comet 67P/Churyumov-Gerasimenko based on DFMS/COPS data from 2014-2016Comments: ancillary files to create the plots in figure 2Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
The coma of comet 67P/Churyumov-Gerasimenko has been probed by the Rosetta spacecraft and shows a variety of different molecules. The ROSINA COmet Pressure Sensor and the Double Focusing Mass Spectrometer provide in-situ densities for many volatile compounds including the 14 gas species H2O, CO2, H2S, CO, O2, C2H6, CH3OH, H2CO, CH4, NH3, C2H5OH, HCN, OCS, and CS2. We fit the observed densities during the entire comet mission between August 2014 and September 2016 to an inverse coma model. We retrieve surface emissions on a cometary shape with 3996 triangular elements for 50 separated time intervals. For each gas we derive systematic error bounds and report the temporal evolution of the production, peak production, and the time-integrated total production. We discuss the production for the two lobes of the nucleus and for the northern and southern hemispheres. Moreover we provide a comparison of the gas production with the seasonal illumination.
- [57] arXiv:2006.01762 [pdf, other]
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Title: Cosmological constraints on non-adiabatic dark energy perturbationsComments: 15 pages, 7 figures, 5 tables, comments welcome. The RSD Montepython likelihood can be found at this https URLSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
The exact nature of dark energy is currently unknown and its cosmological perturbations, when dark energy is assumed not to be the cosmological constant, are usually modelled as adiabatic. Here we explore the possibility that dark energy might have a non-adiabatic component and we examine how it would affect several key cosmological observables. We present analytical solutions for the growth-rate and growth index of matter density perturbations and compare them to both numerical solutions of the fluid equations and an implementation in the Boltzmann code CLASS, finding they all agree to well below one percent. We also perform a Monte-Carlo analysis to derive constraints on the parameters of the non-adiabatic component using the latest cosmological data, including the temperature and polarization spectra of the Cosmic Microwave Background as observed by Planck, the Baryon Acoustic Oscillations, the Pantheon type Ia supernovae compilation and lastly, measurements of Redshift Space Distortions (RSD) of the growth-rate of matter perturbations. We find that the amplitude of the non-adiabatic pressure perturbation is consistent with zero within $1\sigma$. Finally, we also present a new, publicly available, RSD likelihood for MontePython based on the "Gold 2018" growth-rate data compilation.
- [58] arXiv:2006.01783 [pdf, other]
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Title: Chronologically dating the early assembly of the Milky WayAuthors: Josefina Montalbán (1), John Ted Mackereth (1), Andrea Miglio (1 and 2), Fiorenzo Vincenzo (3,4 and 1), Cristina Chiappini (5), Gaël Buldgen (6), Benoît Mosser (7), Arlette Noels (8), Richard Scuflaire (8), Mathieu Vrard (4 and 10), Emma Willett (1 and 2), Guy R. Davies (1 and 2), Oliver Hall (1 and 2) Martin Bo Nielsen (1,2 and 11), Saniya Khan (1 and 2), Ben M. Rendle (1 and 2), Walter E. van Rossem (1 and 2), Jason W. Ferguson (9), William J. Chaplin (1 and 2) ((1) School of Physics and Astronomy, University of Birmingham, UK, (2) SAC, Aarhus University, Denmark, (3) Center for Cosmology and AstroParticle Physics, The Ohio State University, USA, (4) Departement of Astronomy, The Ohio State University, USA, (5) Leibniz-Institut fur Astrophysik Potsdam, Germany, (6) Observatoire de Genève, Université de Genève, Switzerland, (7) LESIA, Observatoire de Paris, Université de Paris, France, (8) STAR Institute, University of Liège, Belgium, (9) Departement of Physics, Wichita State University, USA, (10) Instituto de Astrofśica e Ciências do Espaço, Universidade do Porto, Portugal, (11) Center for Space Science, NYUAD, New York University Abu Dhabi, United Arab Emirates)Comments: 39 pages, 11 figures, SubmittedSubjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
The Milky Way, like other disc galaxies, underwent violent mergers and accretion of smaller satellite galaxies in its early history. Thanks to $\mathit Gaia$-DR2 and spectroscopic surveys, the stellar remnants of such mergers have been identified. The chronological dating of such events is crucial to uncover the formation and evolution of the Galaxy at high redshift, but it has so far been challenging owing to difficulties in obtaining precise ages for these oldest stars. Here we combine asteroseismology -- the study of stellar oscillations -- with kinematics and chemical abundances, to estimate precise stellar ages ($\sim$ 11%) for a sample of stars observed by the $\mathit{Kepler}$ space mission. Crucially, this sample includes not only some of the oldest stars that were formed inside the Galaxy, but also stars formed externally and subsequently accreted onto the Milky Way. Leveraging this unprecedented temporal resolution in age, we provide overwhelming evidence in favour of models in which the Galaxy had already formed a significant population of its stars (which now reside mainly in its thick disc) before the in-fall of the satellite galaxy $\mathit{Gaia}$-$\mathit{Enceladus}$ 10 billions years ago.
- [59] arXiv:2006.01788 [pdf, other]
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Title: A Mechanism of Spark Motion in Inner Acceleration Region to Investigate Subpulse Drifting in PulsarsComments: 22 pages, 19 figures, Accepted for publication in MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Coherent radio emission in pulsars is excited due to instabilities in a relativistically streaming non-stationary plasma flow, which is generated from sparking discharges in the inner acceleration region (IAR) near the stellar surface. A number of detailed works have shown the IAR to be a partially screened gap (PSG) dominated by non-dipolar magnetic fields with continuous outflow of ions from the surface. The phenomenon of subpulse drifting is expected to originate due to variable $\mathbf{E}\times\mathbf{B}$ drift of the sparks in PSG, where the sparks lag behind corotation velocity of the pulsar. Detailed observations show a wide variety of subpulse drifting behaviour where subpulses in different components of the profile have different phase trajectories. But the drifting periodicity is seen to be constant, within measurement errors, across all components of the profile. Using the concept of sparks lagging behind corotation speed in PSG as well as the different orientations of the surface non-dipolar magnetic fields we have simulated the expected single pulse behaviour in a representative sample of pulsars. Our results show that the different types of drifting phase behaviour can be reproduced using these simple assumptions of spark dynamics in a non-dipolar IAR.
- [60] arXiv:2006.01806 [pdf, other]
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Title: OSSOS XX: The Meaning of Kuiper Belt ColorsAuthors: David Nesvorny, David Vokrouhlicky, Mike Alexandersen, Michele T. Bannister, Laura E. Buchanan, Ying-Tung Chen, Brett J. Gladman, Stephen D. J. Gwyn, J. J. Kavelaars, Jean-Marc Petit, Megan E. Schwamb, Kathryn VolkComments: AJ, in pressSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
Observations show that 100-km-class Kuiper belt objects (KBOs) can be divided in (at least) two color groups, hereafter red (R, g-i<1.2) and very red (VR, g-i>1.2), reflecting a difference in their surface composition. This is thought to imply that KBOs formed over a relatively wide range of radial distance, r. The cold classicals at 42<r<47 au are predominantly VR and known Neptune Trojans at r=30 au are mostly R. Intriguingly, however, the dynamically hot KBOs show a mix of R and VR colors and no correlation of color with r. Here we perform migration/instability simulations where the Kuiper belt is populated from an extended planetesimal disk. We find that the color observations can be best understood if R objects formed at r<r* and VR objects at r>r*, with 30<r*<40 au. The proposed transition at 30<r*<40 au would explain why the VR objects in the dynamically hot population have smaller orbital inclinations than the R objects, because the orbital excitation from Neptune weakens for orbits starting beyond 30 au. Possible causes of the R-VR color bimodality are discussed.
- [61] arXiv:2006.01807 [pdf, ps, other]
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Title: The Fate of Binary Stars Hosting Planets upon Interaction with Sgr A* Black holeAuthors: Roberto Capuzzo-Dolcetta, Nazanin Davari (Dep. of Physics, Sapienza, Universita`di Roma, Italy)Comments: 10 pages, 5 figures, 4 tables. Accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
Our Galaxy hosts a very massive object at its centre, often referred to as the supermassive black hole Sgr A*. Its gravitational tidal field is so intense that can strip apart a binary star passing its vicinity and accelerate one of the components of the binary as hypervelocity star (HVS) and grab the other star as S-star. Taken into consideration that many binary star systems are known to host planets, in this paper we aim to broaden the study of the close interaction of binary stars and their planetary systems with Sgr A* massive object. Results are obtained via a high precision $N-$body code including post-Newtonian approximation. We quantify the likelihood of capture and ejection of stars and planets after interaction with Sgr A*, finding that the fraction of stars captured around it is about three times that of the planets (~ 49.4% versus ~14.5%) and the fraction of hypervelocity planet (HVP) ejection is about twice HVSs (~21.7% versus ~9.0%). The actual possibility of observational counterparts deserves further investigation.
- [62] arXiv:2006.01809 [pdf, other]
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Title: Ubiquitous hundred-Gauss magnetic fields in solar spiculesSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
Aims. We use high-resolution spectropolarimetric observations in the Ca ii 8542 A line obtained with the SST to study the magnetic field in solar spicules. Methods. The equations that result from the application of the Weak Field Approximation (WFA) to the radiative transfer equations are used to infer the LOS component of the magnetic field (BLOS). Two restrictive conditions are imposed on the Stokes I and V profiles at each pixel before they can be used in a Bayesian inversion to compute its BLOS. Results. The LOS magnetic field component has been inferred in six data sets totalling 448 spectral scans in the Ca ii 8542 A line and containing both active region and quiet Sun areas, with values of hundreds of G being abundantly inferred. There seems to be no difference, from the statistical point of view, between the magnetic field strength of spicules in the quiet Sun or near an active region. On the other hand, the BLOS distributions present smaller values on the disk than off-limb, a fact that can be explained by the effect of superposition on the chromosphere of on-disk structures. We find that spicules in the vicinity of a sunspot have a magnetic field polarity (i.e. north or south) equal to that of the sunspot. This paper also contains an analysis of the effect of off-limb overlapping structures on the observed Stokes I and V parameters and the BLOS obtained from the WFA. It is found that this value is equal to or smaller than the largest LOS magnetic field components of the two structures. In addition, using random BLOS, Doppler velocities and line intensities of these two structures leads in ~ 50% of the cases to Stokes I and V parameters unsuitable to be used with the WFA. Conclusions. Our results present a scarcity of LOS magnetic field components smaller than some 50 G, which must not be taken as evidence against the existence of these magnetic field strengths in spicules.
- [63] arXiv:2006.01811 [pdf, other]
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Title: The effects on CMB power spectra and bispectra from the polarization rotation and its correlations with temperature and E-polarizationComments: 24 pages, 5 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The Chern-Simons term, through which the cosmic Axion-like field couples to the electromagnetic field, has the effect to rotate CMB polarization directions and to break the CPT symmetry. This rotation will change the CMB power spectra, no matter isotropic or anisotropic the rotation angle is. In this paper we revisit this issue by further considering the correlations between the (anisotropic) rotation angle $\alpha$ and the CMB temperature and (unrotated) $E$ polarization fields. These correlations could be generated in the Axion-like models with nonzero potential under the adiabatic initial condition. We first investigate how these correlations contribute further modifications to the CMB power spectra, then calculate the CMB bispectra for the temperature and rotated polarization fields. These bispectra would vanish if the $T\alpha$ and $E\alpha$ correlations are absent. So, they are useful in searching for CPT violation and the $T\alpha$ and $E\alpha$ correlations arisen in the Axion-like models.
- [64] arXiv:2006.01814 [pdf, other]
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Title: Influence of the Galactic gravitational field on the positional accuracy of extragalactic sources. II Observational appearances and detectabilityComments: accepted for publication in AJ. This work is a continuation of our earlier paper Larchenkova et al. 2017 (arXiv:1702.00400)Subjects: Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
We consider a possibility of detecting the jitter effect of apparent celestial positions of distant sources due to local fluctuations of the Galaxy gravitational field. It is proposed to observe two samples of extragalactic sources (target and control) in different sky directions using the high-precision radio interferometry. It is shown that on a scale of ~2 years, it is possible to detect a systematic increase in the standard deviation of measured arc lengths of pairs of target sources compared to the control ones at the $3\sigma$-level if the accuracy of differential astrometric observations is around 10 $\mu$as. For the current state-of-the-art accuracy of 30 $\mu$as achieved at the KVN or VERA interferometers, which have shorter baselines in comparison with VLBI, the target and control samples will differ only at the 2$\sigma$-level on the scale of 10 years. To achieve the $3\sigma$-level on this time interval, it is necessary to improve the accuracy up to ~20 $\mu$as. Other possible effects that can also affect the arc length measurements between two sources are discussed, and an observational strategy to minimize them is suggested.
- [65] arXiv:2006.01822 [pdf, ps, other]
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Title: Inflationary gravitational waves and exotic pre Big Bang Nucleosynthesis cosmologyComments: 6 pages, 2 figures, Proceeding article - 10th Young Researcher Meeting, June 2019,Journal-ref: Journal of Physics: Conference Series (JPCS), 1548 (2020) 012010Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
According to the most popular scenario, the early Universe should have experienced an accelerated expansion phase, called Cosmological Inflation, after which the standard Big Bang Cosmology would have taken place giving rise to the radiation-dominated epoch. However, the details of the inflationary scenario are far to be completely understood. Thus, in this paper we study if possible additional (exotic) cosmological phases could delay the beginning of the standard Big Bang history and alter some theoretical predictions related to the inflationary cosmological perturbations, like, for instance, the order of magnitude of the tensor-to-scalar ratio $r$.
- [66] arXiv:2006.01826 [pdf, other]
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Title: Observational Support for Massive Black Hole Formation Driven by Runaway Stellar Collisions in Galactic NucleiAuthors: Andres EscalaComments: comments welcome (aescala@das.uchile.cl)Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
We explore here an scenario for massive black hole formation driven by stellar collisions in galactic nuclei, proposing a new formation regime of global instability in nuclear stellar clusters triggered by runaway stellar collisions. Using order of magnitude estimations, we show that observed nuclear stellar clusters avoid the regime where stellar collision are dynamically relevant over the whole system, while resolved detections of massive black holes are well into such collision-dominated regime. We interpret this result in terms of massive black holes and nuclear stellar clusters being different evolutionary paths of a common formation mechanism, unified under the standard terminology of being both central massive objects. We propose a formation scenario where central massive objects more massive than $\rm \sim 10^8 \, M_O$ will be too dense (in virial equilibrium) to be globally stable against stellar collisions and most of its mass will collapse towards the formation of a massive black hole. Contrarily, this will only be the case at the core of less dense central massive objects leading to the formation of black holes with much lower black hole efficiencies $\rm \epsilon_{BH} = \frac{M_{BH}}{M_{CMO}}$, with these efficiencies $\rm \epsilon_{BH}$ drastically growing for central massive objects more massive than $\rm \sim 10^7 \,M_O$, approaching unity around $\rm M_{CMO} \sim 10^8 \, M_O$. We show that the proposed scenario successfully explain the relative trends observed in the masses, efficiencies and scaling relations between massive black holes and nuclear stellar cluster
- [67] arXiv:2006.01827 [pdf, other]
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Title: Hydrodynamic Simulations of Classical Novae; CO and ONe White Dwarfs are Supernova Ia ProgenitorsComments: To appear in "The Golden Age of Cataclysmic Variables and Related Objects V (GOLDEN2019)" 2-7 September 2019, Palermo, Italy. Proceedings of Science, in pressSubjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)
Cataclysmic Variables (CVs) and Symbiotic Binaries are close (or not so close) binary star systems which contain both a white dwarf (WD) primary and a larger cooler secondary star that typically fills its Roche Lobe. The cooler star is losing mass through the inner Lagrangian point of the binary and a fraction of this material is accreted by the WD. Here we report on our hydrodynamic studies of the thermonuclear runaway (TNR) in the accreted material that ends in a Classical Nova explosion. We have followed the evolution of the TNRs on both carbon-oxygen (CO) and oxygen-neon (ONe) WDs. We report on 3 studies in this paper. First, simulations in which we accrete only solar matter using NOVA (our 1-D, fully implicit, hydro code). Second, we use MESA for similar studies in which we accrete only Solar matter and compare the results. Third, we accrete solar matter until the TNR is ongoing and then switch the composition in the accreted layers to a mixed composition: either 25% WD and 75% solar or 50% WD and 50% Solar matter. We find that the amount of accreted material is inversely proportional to the initial 12C abundance (as expected). Thus, accreting solar matter results in a larger amount of accreted material to fuel the outburst; much larger than in earlier studies where a mixed composition was assumed from the beginning of the simulation. Our most important result is that all these simulations eject significantly less mass than accreted and, therefore, the WD is growing in mass toward the Chandrasekhar Limit.
Cross-lists for Wed, 3 Jun 20
- [68] arXiv:2006.01141 (cross-list from hep-ph) [pdf, other]
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Title: Unified weak/strong coupling framework for nuclear matter and neutron starsComments: 39 pages, 16 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th); Nuclear Theory (nucl-th)
Ab initio methods using weakly interacting nucleons give a good description of condensed nuclear matter up to densities comparable to the nuclear saturation density. At higher densities palpable strong interactions between overlapping nucleons become important; we propose that the interactions will continuously switch over to follow a holographic model in this region. In order to implement this, we construct hybrid equations of state (EoSs) where various models are used for low density nuclear matter, and the holographic V-QCD model is used for non-perturbative high density nuclear matter as well as for quark matter. We carefully examine all existing constraints from astrophysics of compact stars and discuss their implications for the hybrid EoSs. Thanks to the stiffness of the V-QCD EoS for nuclear matter, we obtain a large family of viable hybrid EoSs passing the constraints. We find that quark matter cores in neutron stars are unstable due to the strongly first order deconfinement transition, and predict bounds on the tidal deformability as well as on the radius of neutron stars. By relying on universal relations, we also constrain characteristic peak frequencies of gravitational waves produced in neutron star mergers.
- [69] arXiv:2006.01149 (cross-list from hep-ph) [pdf, other]
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Title: Dark matter relic density from conformally or disformally coupled light scalarsComments: 17 pages, 3 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
Thermal freeze-out is a prominent example of dark matter (DM) production mechanism in the early Universe that can yield the correct relic density of stable weakly interacting massive particles (WIMPs). At the other end of the mass scale, many popular extensions of the Standard Model predict the existence of ultra-light scalar fields. These can be coupled to matter, preferentially in a universal and shift-symmetry-preserving way. We study the impact of such conformal and disformal couplings on the relic density of WIMPs, without introducing modifications to the thermal history of the Universe. This can either result in an additional thermal contribution to the DM relic density or suppress otherwise too large abundances compared to the observed levels. In this work, we assume that the WIMPs only interact with the standard model via the light scalar portal. We use simple models of fermionic or scalar DM, although a similar discussion holds for more sophisticated scenarios, and predict that their masses should be between $\sim 100~\textrm{GeV}$ and several $\textrm{TeV}$ to comply both with the DM abundance and current bounds on the couplings of the light scalars to matter at the LHC. Future searches will tighten these bounds.
- [70] arXiv:2006.01153 (cross-list from gr-qc) [pdf, other]
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Title: The onset of spontaneous scalarization in generalised scalar-tensor theoriesComments: 10 pages, 10 figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)
In gravity theories that exhibit spontaneous scalarization, astrophysical objects are identical to their general relativistic counterpart until they reach a certain threshold in compactness or curvature. Beyond this threshold, they acquire a non-trivial scalar configuration, which also affects their structure. The onset of scalarization is controlled only by terms that contribute to linear perturbation around solutions of general relativity. The complete set of these terms has been identified for generalized scalar-tensor theories. Stepping on this result, we study the onset on scalarization in generalized scalar-tensor theories and determine the relevant thresholds in terms of the contributing coupling constants and the properties of the compact object.
- [71] arXiv:2006.01167 (cross-list from physics.pop-ph) [pdf]
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Title: Reworking the SETI Paradox: METI's Place on the Continuum of Astrobiological SignalingAuthors: T. CortellesiComments: 15 pages, submitted to JBIS 31 May 2020Subjects: Popular Physics (physics.pop-ph); Earth and Planetary Astrophysics (astro-ph.EP)
The Search for Extraterrestrial Intelligence (SETI) has heretofore been a largely passive exercise, reliant on the pursuit of technosignatures. Still, there are those that advocate a more active approach. Messaging Extraterrestrial Intelligence (METI) has had a controversial history within the larger SETI project; it is claimed that the risks involved outweigh any potential benefits. These arguments are ultimately not compelling, result in absurd policy recommendations, and rest on a faulty appreciation of the nature of technosignatures, whose detectability implies intent to signal. Present technology is advancing quickly such that we will soon have great observational reach, to the point of reliably detecting such technosignatures and biosignatures: a capability that can be matched or exceeded elsewhere. To escape the SETI Paradox properly defined, at least one technological civilization must choose not to suppress its own continuum of astrobiological signals, of which METI is merely the most effective endmember. Passive SETI's low likelihood of success in the short-term is a serious obstacle to sustainable funding, alongside a 'giggle factor' enhanced by a pernicious fear of contact. The scientific community must integrate an active approach to better ensure both the continuity and eventual success of the SETI project.
- [72] arXiv:2006.01390 (cross-list from gr-qc) [pdf, ps, other]
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Title: Reissner-Nordström-de Sitter black hole immersed in perfect fluid dark matter cannot be overchargedComments: 9 pages, no figureSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)
On the contrary to the well-known result that the Reissner-Nordstr\"{o}m (RN) black hole could be overcharged under linear order particle accretion it is shown that the same black hole in perfect fluid dark matter with cosmological parameter cannot be overcharged. Taking into account that in a realistic scenario black holes can not be considered to be in vacuum we investigate the contribution of dark matter and cosmological parameters to overcharging process of charged black hole. We show that the black hole can be overcharged only when two fields induced by dark matter and cosmological parameter are completely balanced. Further we give a remarkable result that black hole cannot be overcharged beyond a certain threshold limit for which the effect arising from the cosmological parameter dominates over the effect due to the perfect fluid dark matter. Though even for linear accretion process, the black hole cannot always be overcharged and hence obeys the weak cosmic censorship conjecture (WCCC). This result would always be fulfilled for non-linear order accretion.
- [73] arXiv:2006.01406 (cross-list from hep-ph) [pdf, ps, other]
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Title: Gravitational waves from breaking of an extra $U(1)$ in $SO(10)$ grand unificationComments: 21 pages, 3 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
In a class of gauged $U(1)$ extended Standard Models (SMs), the breaking of the $U(1)$ symmetry is not only a source for Majorana masses of right-handed (RH) neutrinos crucial for the seesaw mechanism, but also a source of stochastic gravitational wave (GW) background. Such $U(1)$ extended models are well-motivated from the viewpoint of grand unification. In this paper, we discuss a successful ultraviolet completion of a $U(1)$ extended SM by an $SO(10)$ grand unified model through an intermediate step of $SU(5) \times U(1)$ unification. With a parameter set that is compatible with the $SO(10)$ grand unification, we find that a first-order phase transition associated with the $U(1)$ symmetry breaking can be strong enough to generate GWs with a detectable size of amplitude. We also find that the resultant GW amplitude reduces and its peak frequency becomes higher as the RH neutrino masses increase.
- [74] arXiv:2006.01452 (cross-list from gr-qc) [pdf, other]
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Title: Three-dimensional general relativistic Poynting-Robertson effect. III. Static and non-spherical quadrupolar massive sourceComments: 16 pages, 11 figures. Paper accepted on the 2nd of June 2020 on Phys. Rev. DSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)
We investigate the three-dimensional motion of a test particle in the gravitational field generated by a non-spherical compact object endowed with a mass quadrupole moment, described by the Erez-Rosen metric, and a radiation field, including the general relativistic Poynting-Robertson effect, coming from a rigidly rotating spherical emitting source located outside of the compact object. We derive the equations of motion for test particles influenced by such radiation field, recovering the two-dimensional description, and the weak-field approximation. This dynamical system admits the existence of a critical hypersurface, region where gravitational and radiation forces balance. Selected test particle orbits for different set of input parameters are displayed. The possible configurations on the critical hypersurfaces can be either latitudinal drift towards the equatorial ring or suspended orbits. We discuss about the existence of multiple hypersurface solutions through a simple method to perform the calculations. We graphically prove also that the critical hypersurfaces are stable configurations within the Lyapunov theory.
- [75] arXiv:2006.01462 (cross-list from gr-qc) [pdf, other]
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Title: New approaches to the general relativistic Poynting-Robertson effectAuthors: Vittorio De FalcoComments: 12 pages, 5 figures, accepted on the 1st of June 2020 on Emerging Science JournalSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)
Objectives: A systematic study on the general relativistic Poynting-Robertson effect has been developed so far by introducing different complementary approaches, which can be mainly divided in two kinds: (1) improving the theoretical assessments and model in its simple aspects, and (2) extracting mathematical and physical information from such system with the aim to extend methods or results to other similar physical systems of analogue structure.
Methods/Analysis: We use these theoretical approaches: relativity of observer splitting formalism; Lagrangian formalism and Rayleigh potential with a new integration method; Lyapunov theory os stability.
Findings: We determined the three-dimensional formulation of the general relativistic Poynting-Robertson effect model. We determine the analytical form of the Rayleigh potential and discuss its implications. We prove that the critical hypersurfaces (regions where there is a balance between gravitational and radiation forces) are stable configurations.
Novelty /Improvement: Our new contributions are: to have introduced the three-dimensional description; to have determined the general relativistic Rayleigh potential for the first time in the General Relativity literature; to have provided an alternative, general and more elegant proof of the stability of the critical hypersurfaces. - [76] arXiv:2006.01490 (cross-list from stat.ML) [pdf, other]
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Title: Bayesian Neural NetworksComments: DRAFT v0 for chapter on Bayesian neural networks in Artificial Intelligence for Particle Physics. 41 pagesSubjects: Machine Learning (stat.ML); Instrumentation and Methods for Astrophysics (astro-ph.IM); Machine Learning (cs.LG)
In recent times, neural networks have become a powerful tool for the analysis of complex and abstract data models. However, their introduction intrinsically increases our uncertainty about which features of the analysis are model-related and which are due to the neural network. This means that predictions by neural networks have biases which cannot be trivially distinguished from being due to the true nature of the creation and observation of data or not. In order to attempt to address such issues we discuss Bayesian neural networks: neural networks where the uncertainty due to the network can be characterised. In particular, we present the Bayesian statistical framework which allows us to categorise uncertainty in terms of the ingrained randomness of observing certain data and the uncertainty from our lack of knowledge about how data can be created and observed. In presenting such techniques we show how errors in prediction by neural networks can be obtained in principle, and provide the two favoured methods for characterising these errors. We will also describe how both of these methods have substantial pitfalls when put into practice, highlighting the need for other statistical techniques to truly be able to do inference when using neural networks.
- [77] arXiv:2006.01519 (cross-list from physics.ins-det) [pdf, other]
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Title: A universal smartphone add-on for portable spectroscopy and polarimetry: iSPEX 2Authors: Olivier Burggraaff, Armand B. Perduijn, Robert F. van Hek, Norbert Schmidt, Christoph U. Keller, Frans SnikComments: 16 pages, 11 figures, SPIE Defense + Commercial Sensing 2020Journal-ref: Proc. SPIE 11389, Micro- and Nanotechnology Sensors, Systems, and Applications XII, 113892K (20 May 2020)Subjects: Instrumentation and Detectors (physics.ins-det); Instrumentation and Methods for Astrophysics (astro-ph.IM); Atmospheric and Oceanic Physics (physics.ao-ph); Optics (physics.optics)
Spectropolarimetry is a powerful technique for remote sensing of the environment. It enables the retrieval of particle shape and size distributions in air and water to an extent that traditional spectroscopy cannot. SPEX is an instrument concept for spectropolarimetry through spectral modulation, providing snapshot, and hence accurate, hyperspectral intensity and degree and angle of linear polarization. Successful SPEX instruments have included groundSPEX and SPEX airborne, which both measure aerosol optical thickness with high precision, and soon SPEXone, which will fly on PACE. Here, we present a low-cost variant for consumer cameras, iSPEX 2, with universal smartphone support. Smartphones enable citizen science measurements which are significantly more scaleable, in space and time, than professional instruments. Universal smartphone support is achieved through a modular hardware design and SPECTACLE data processing. iSPEX 2 will be manufactured through injection molding and 3D printing. A smartphone app for data acquisition and processing is in active development. Production, calibration, and validation will commence in the summer of 2020. Scientific applications will include citizen science measurements of aerosol optical thickness and surface water reflectance, as well as low-cost laboratory and portable spectroscopy.
- [78] arXiv:2006.01562 (cross-list from gr-qc) [pdf, ps, other]
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Title: A conjecture about the general cosmological solution of Einstein's equationsAuthors: John D. BarrowComments: 7 pages, no figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
We introduce consideration of a new factor, synchronisation of spacetime Mixmaster oscillations, that may play a simplifying role in understanding the nature of the general inhomogeneous cosmological solution to Einstein's equations. We conjecture that, on approach to a singularity, the interaction of spacetime Mixmaster oscillations in different regions of an inhomogeneous universe can produce a synchronisation of these oscillations through a coupling to their mean field in the way first demonstrated by the Kuramoto coupled oscillator model.
- [79] arXiv:2006.01580 (cross-list from gr-qc) [pdf, other]
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Title: Cosmological constraints on the Generalized Uncertainty Principle from modified Friedmann equationsComments: 12 pages. Comments are welcome!Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The Generalized Uncertainty Principle (GUP) has emerged in numerous attempts to a theory of quantum gravity and predicts the existence of a minimum length in Nature. In this work, we consider two cosmological models arising from Friedmann equations modified by the GUP (in its linear and quadratic formulations) and compare them with observational data. Our aim is to derive constraints on the GUP parameter and discuss the viability and physical implications of such models. We find that the parameter in the quadratic formulation has the constraint $\alpha^{2}_{Q}<10^{59}$ (tighter than most of those obtained in an astrophysical context) while the linear formulation does not appear compatible with present cosmological data. Our analysis highlights the powerful role of high-precision cosmological probes in the realm of quantum gravity phenomenology.
- [80] arXiv:2006.01618 (cross-list from gr-qc) [pdf, ps, other]
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Title: Interacting Tsallis holographic dark energy in higher dimensional CosmologyComments: 7 pages, 7 figures, prepared for Astronomy and Space Science. To be published on Astronomy and Space ScienceSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We discuss Tsallis holographic dark energy (THDE) model in higher dimension. An interacting dark energy model is proposed with Generalized Chaplygin Gas (GCG) in the framework of Compact Kaluza-Klein gravity. It is shown that a stable configuration can be found in the present epoch which is also compatible with the observed value of the density parameter. It is noted that dark energy (DE) might have evolved from a phantom phase in the past. Nature of dark energy is found to depend on the coupling parameter of the interaction. Classical stability consideration is also found to put an upper bound on the model parameter.
- [81] arXiv:2006.01624 (cross-list from hep-ph) [pdf, other]
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Title: Charged charm starsComments: 5 pages, 5 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
The study of the general properties and stability of charm stars with a net electric charge is performed within the MIT bag model framework. We consider two different models for the electric charge distribution and demostrate that both imply stellar configurations with larger masses and that satisfy the equilibrium condition. The dynamical stability against radial oscillations is investigated. Our results demonstrate that the eigenfrequencies are modified by the presence of a net electric charge, but the instability, previously demonstrated for the electrically neutral case, is also present in charged charm stars.
- [82] arXiv:2006.01636 (cross-list from hep-ph) [pdf, ps, other]
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Title: Spin oscillations of neutrinos scattered off a rotating black holeAuthors: Maxim Dvornikov (IZMIRAN)Comments: 22 pages, 20 eps figures, LaTeX2e, published version. arXiv admin note: substantial text overlap with arXiv:1911.08317Journal-ref: Eur. Phys. J. C 80, 474 (2020)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
Spin oscillations of neutrinos, gravitationally scattered off a black hole (BH), are studied. The cases of nonrotating and rotating BHs are analyzed. We derive the analytic expressions for the transition and survival probabilities of spin oscillations when neutrinos interact with these gravitational backgrounds. The obtained transition probabilities depend on the impact parameter, as well as the neutrino energy and the particle mass. We find that there is a possibility of spin oscillations of ultrarelativistic neutrinos scattering off a rotating BH. Then, considering the neutrino scattering off BH surrounded by background matter, we derive the effective Schrodinger equation for spin oscillations. The numerical solution of this equation is obtained in the case of a supermassive BH with a realistic accretion disk. Spin effects turn out to be negligible in the neutrino scattering in the Schwarzschild metric. In the Kerr metric, we find that the observed neutrino fluxes can be reduced almost 10% because of spin oscillations when ultrarelativistic neutrinos experience gravitational scattering. The neutrino interaction with an accretion disk results in the additional modification of the intensities of outgoing neutrino fluxes. We consider the applications of the obtained results for the neutrino astronomy.
- [83] arXiv:2006.01706 (cross-list from math-ph) [pdf, ps, other]
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Title: The invariance of the diffusion coefficient with the iterative operations of charged particles' transport equationSubjects: Mathematical Physics (math-ph); High Energy Astrophysical Phenomena (astro-ph.HE)
The Spatial Parallel Diffusion Coefficient (SPDC) is one of the important quantities describing energetic charged particle transport. There are three different definitions for the SPDC, i.e., the Displacement Variance definition $\kappa_{zz}^{DV}=\lim_{t\rightarrow t_{\infty}}d\sigma^2/(2dt)$, the Fick's Law definition $\kappa_{zz}^{FL}=J/X$ with $X=\partial{F}/\partial{z}$, and the TGK formula definition $\kappa_{zz}^{TGK}=\int_0^{\infty}dt \langle v_z(t)v_z(0) \rangle$. For constant mean magnetic field, the three different definitions of the SPDC give the same result. However, for focusing field it is demonstrated that the results of the different definitions are not the same. In this paper, from the Fokker-Planck equation we find that different methods, e.g., the general Fourier expansion and perturbation theory, can give the different Equations of the Isotropic Distribution Function (EIDFs). But it is shown that one EIDF can be transformed into another by some Derivative Iterative Operations (DIOs). If one definition of the SPDC is invariant for the DIOs, it is clear that the definition is also an invariance for different EIDFs, therewith it is an invariant quantity for the different Derivation Methods of EIDF (DMEs). For the focusing field we suggest that the TGK definition $\kappa_{zz}^{TGK}$ is only the approximate formula, and the Fick's Law definition $\kappa_{zz}^{FL}$ is not invariant to some DIOs. However, at least for the special condition, in this paper we show that the definition $\kappa_{zz}^{DV}$ is the invariant quantity to the kinds of the DIOs. Therefore, for spatially varying field the displacement variance definition $\kappa_{zz}^{DV}$, rather than the Fick's law definition $\kappa_{zz}^{FL}$ and TGK formula definition $\kappa_{zz}^{TGK}$, is the most appropriate definition of the SPDCs.
Replacements for Wed, 3 Jun 20
- [84] arXiv:1904.02167 (replaced) [pdf, other]
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Title: The impact of magnetic fields on cold streams feeding galaxiesComments: 19 pages, 15 figures, accepted for publication in MNRAS, animations of Figures 4 and 5 at this http URLSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [85] arXiv:1908.03013 (replaced) [pdf, other]
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Title: Application of the independent component analysis to the iKAGRA dataAuthors: KAGRA Collaboration: T. Akutsu, M. Ando, K. Arai, Y. Arai, S. Araki, A. Araya, N. Aritomi, H. Asada, Y. Aso, S. Atsuta, K. Awai, S. Bae, Y. Bae, L. Baiotti, R. Bajpai, M. A. Barton, K. Cannon, E. Capocasa, M. Chan, C. Chen, K. Chen, Y. Chen, H. Chu, Y-K. Chu, K. Craig, W. Creus, K. Doi, K. Eda, S. Eguchi, Y. Enomoto, R. Flaminio, Y. Fujii, M.-K. Fujimoto, M. Fukunaga, M. Fukushima, T. Furuhata, G. Ge, A. Hagiwara, S. Haino, K. Hasegawa, K. Hashino, H. Hayakawa, K. Hayama, Y. Himemoto, Y. Hiranuma, N. Hirata, S. Hirobayashi, E. Hirose, Z. Hong, B. H. Hsieh, G-Z. Huang, P. Huang, Y. Huang, B. Ikenoue, S. Imam, K. Inayoshi, Y. Inoue, K. Ioka, Y. Itoh, K. Izumi, K. Jung, P. Jung, T. Kaji, T. Kajita, M. Kakizaki, M. Kamiizumi, S. Kanbara, N. Kanda, S. Kanemura, M. Kaneyama, G. Kang, J. Kasuya, et al. (179 additional authors not shown)Comments: 27 pages, 12 figures : published in PTEP with added discussion about the relation between ICA and Wiener filteringJournal-ref: Progress of Theoretical and Experimental Physics, Volume 2020, Issue 5, May 2020, 053F01Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); General Relativity and Quantum Cosmology (gr-qc)
- [86] arXiv:1908.04736 (replaced) [pdf, other]
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Title: Setting nonperturbative uncertainties on finite-temperature properties of neutron matterAuthors: Arianna CarboneComments: 7 pages, 4 figures; article reorganized in sections, added paragraphs and referencesJournal-ref: Phys. Rev. Research 2, 023227 (2020)Subjects: Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Experiment (nucl-ex)
- [87] arXiv:1908.08404 (replaced) [pdf, ps, other]
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Title: ALMA CO Observations of a Giant Molecular Cloud in M33: Evidence for High-Mass Star Formation Triggered by Cloud-Cloud CollisionsAuthors: Hidetoshi Sano, Kisetsu Tsuge, Kazuki Tokuda, Kazuyuki Muraoka, Kengo Tachihara, Yumiko Yamane, Mikito Kohno, Shinji Fujita, Rei Enokiya, Gavin Rowell, Nigel Maxted, Miroslav D. Filipovic, Jonathan Knies, Manami Sasaki, Toshikazu Onishi, Paul P. Plucinsky, Yasuo FukuiComments: 13 pages, 10 figures, 1 table, accepted for publication in PASJSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [88] arXiv:1909.10328 (replaced) [pdf, other]
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Title: Cosmological viable models in $f(T,B)$ gravity as solutions to the $H_0$ tensionComments: 21 pages, 8 figuresJournal-ref: Classical and Quantum Gravity 2020Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th); Data Analysis, Statistics and Probability (physics.data-an)
- [89] arXiv:1910.06157 (replaced) [pdf, other]
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Title: Differentiable Strong Lensing: Uniting Gravity and Neural Nets through Differentiable Probabilistic ProgrammingComments: 13 pages, 9 figures. Updated to match version published in MNRASSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Phenomenology (hep-ph)
- [90] arXiv:1910.10395 (replaced) [pdf, other]
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Title: Spectral properties of quasars from Sloan Digital Sky Survey data release 14: The catalogComments: Accepted by ApJS. Catalogs and supplementary materials are available at this https URLSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [91] arXiv:1911.02871 (replaced) [pdf, ps, other]
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Title: Comprehensive Analysis of the Transient X-ray Pulsar MAXI J1409-619Authors: Ç.K. Dönmez (1), M.M. Serim (1,2), S.Ç. İnam (3), Ş. Şahiner (4), D. Çerri-Serim (1), A. Baykal (1) ((1) Physics Department, Middle East Technical University, Ankara, Turkey, (2) TÜBİTAK ULAKBİM, Ankara, Turkey, (3) Department of Electrical and Electronics Engineering, Başkent University, Ankara, Turkey, (4) Department of Electronics and Communication Engineering, Beykent University, İstanbul, Turkey)Comments: 28 pages, 15 figures, revised version accepted for publication in MNRAS Main JournalSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
- [92] arXiv:1911.04648 (replaced) [pdf, other]
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Title: Explanation for why the Early Universe was Stable and Dominated by the Standard ModelComments: 8 pages in double column format, 3 figures. V2: Added further clarificationsSubjects: 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)
- [93] arXiv:1911.11766 (replaced) [pdf, other]
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Title: Measuring lensing ratios with future cosmological surveysComments: 15 pages, 12 figures, 1 table, accepted for publication in PRDSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [94] arXiv:1912.01518 (replaced) [pdf, ps, other]
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Title: Effects of the general relativistic spin precessions on the habitability of rogue planets orbiting supermassive black holesAuthors: Lorenzo IorioComments: LaTex2e, 19 pages, 7 figures, no tables. Minor stylistic changes. At press in The Astrophysical Journal (ApJ)Subjects: Earth and Planetary Astrophysics (astro-ph.EP); General Relativity and Quantum Cosmology (gr-qc); Popular Physics (physics.pop-ph); Space Physics (physics.space-ph)
- [95] arXiv:1912.02569 (replaced) [pdf, other]
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Title: Beyond the Standard Models with Cosmic StringsComments: v2: 96 pages, 34 figures. Results and conclusions unchanged but version considerably extended. New Section 9 illustrates the variety of possible peaked GW spectra. New sub-appendices A.1, A.4, B.5 and B.6. New Appendix F on GW spectrum from global strings. New Appendix G on the impact of the cosmology on the loop size at formation. Version published in JCAPSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [96] arXiv:1912.08875 (replaced) [pdf, other]
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Title: Confronting dark matter co-annihilation of Inert two Higgs Doublet Model with a compressed mass spectrumComments: 41 pages, JHEP accepted versionSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE)
- [97] arXiv:1912.13488 (replaced) [pdf, other]
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Title: Neutrino Non-Standard Interactions via Light Scalars in the Earth, Sun, Supernovae and the Early UniverseComments: 36 pages, 7 figures, 2 Tables, minor changes; version published in PRDJournal-ref: Phys. Rev. D 101, 095029 (2020)Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Experiment (hep-ex)
- [98] arXiv:2001.00584 (replaced) [pdf, other]
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Title: Cosmological Angular Trispectra and Non-Gaussian CovarianceComments: 56 pages, 12 figures, 3 tables; v2: minor corrections, references added, published versionSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
- [99] arXiv:2001.04994 (replaced) [pdf, other]
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Title: Bounds on secret neutrino interactions from high-energy astrophysical neutrinosAuthors: Mauricio Bustamante, Charlotte Amalie Rosenstroem, Shashank Shalgar, Irene Tamborra (Bohr Inst. & U. Copenhagen (main) & DARK)Comments: 8 pages, 5 figures, technical appendix. Matches published versionSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
- [100] arXiv:2001.09355 (replaced) [pdf, other]
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Title: Dissecting the regions around IceCube high-energy neutrinos: growing evidence for the blazar connectionComments: 16 pages, 8 figures, Accepted for publication in MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [101] arXiv:2002.01489 (replaced) [pdf, other]
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Title: New empirical constraints on the cosmological evolution of gas and stars in galaxiesComments: 8 pages, 6 figures, accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [102] arXiv:2002.04652 (replaced) [pdf, other]
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Title: Two important constraints on the inner radii of accretion disksComments: ApJ Letters, in pressSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [103] arXiv:2003.04864 (replaced) [pdf, other]
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Title: Combining neutrino experimental light-curves for pointing to the next Galactic Core-Collapse SupernovaAuthors: Alexis Coleiro, Marta Colomer Molla, Damien Dornic, Massimiliano Lincetto, Vladimir KulikovskiyComments: 11 pages, 6 figures, 6 tables, corresponding authors: Marta Colomer Molla and Vladimir KulikovskiySubjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Experiment (hep-ex)
- [104] arXiv:2003.08943 (replaced) [pdf, other]
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Title: Real-Time Value-Driven Data Augmentation in the Era of LSSTAuthors: Niharika Sravan, Dan Milisavljevic, Jack M. Reynolds, Geoffrey Lentner, Mark Linvill (Department of Physics and Astronomy, Purdue University)Comments: Published in The Astrophysical JournalJournal-ref: Year 2020, Vol 893, Pg 127Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE)
- [105] arXiv:2003.09052 (replaced) [pdf, other]
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Title: Design and operation of the ATLAS Transient Science ServerAuthors: K. W. Smith, S. J. Smartt, D. R. Young, J. L. Tonry, L. Denneau, H. Flewelling, A. N. Heinze, H. J. Weiland, B. Stalder, A. Rest, C. W. Stubbs, J. P. Anderson, T.-W. Chen, P. Clark, A. Do, F. Förster, M. Fulton, J. Gillanders, O. R. McBrien, D. O'Neill, S. Srivastav, D. E. WrightComments: 27 pages, 12 figures. Accepted for publication in PASP on 2020 May 15Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
- [106] arXiv:2004.06936 (replaced) [pdf, other]
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Title: RES-NOVA: A new neutrino observatory based on archaeological leadComments: submitted to PRDSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph)
- [107] arXiv:2004.11312 (replaced) [pdf, ps, other]
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Title: What's in a name: The etymology of astrobiologyComments: Accepted for publication in the International Journal of Astrobiology; 16 pages; 0 figuresSubjects: History and Philosophy of Physics (physics.hist-ph); Earth and Planetary Astrophysics (astro-ph.EP)
- [108] arXiv:2004.11522 (replaced) [pdf, other]
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Title: Spectropolarimetric properties of Swift J1818.0$-$1607: a 1.4 s radio magnetarComments: 10 pages, 5 figures and 1 table. Revised version accepted for publication in The Astrophysical Journal LettersSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [109] arXiv:2004.11921 (replaced) [pdf, other]
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Title: Electron Density Structure of the Local Galactic DiskComments: 17 pages, 4 figures, 3 tables, accepted to ApJSubjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
- [110] arXiv:2005.01661 (replaced) [pdf, other]
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Title: Background Model for the High-Energy Telescope of Insight-HXMTAuthors: Jin-Yuan Liao, Shu Zhang, Xue-Feng Lu, Juan Zhang, Gang Li, Zhi Chang, Yu-Peng Chen, Ming-Yu Ge, Cheng-Cheng Guo, Rui Huang, Jing Jin, Xiao-Bo Li, Xu-Fang Li, Zheng-Wei Li, Cong-Zhan Liu, Fang-Jun Lu, Jian-Yin Nie, Li-Ming Song, Si-Fan Wang, Yuan You, Yi-Fei Zhang, Hai-Sheng Zhao, Shuang-Nan ZhangComments: 27 pages, 16 figures, accepted by Journal of High Energy AstrophysicsSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE)
- [111] arXiv:2005.02395 (replaced) [pdf, other]
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Title: Bayesian constraints on the astrophysical neutrino source population from IceCube dataComments: Updated to match version accepted in PRD. Minor changes, including a new figure that shows the n0-evolution dependence more clearlySubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM)
- [112] arXiv:2005.03753 (replaced) [pdf, other]
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Title: Generating primordial fluctuations from modified teleparallel gravity with local Lorentz-symmetry breakingComments: 9 pages, 2 figures, we have added Eqs. (28), (29), (30), and a new section with application to power-law inflationSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
- [113] arXiv:2005.06479 (replaced) [src]
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Title: Living with Neighbors. III. Scrutinizing the Spin$-$Orbit Alignment of Interacting Dark Matter Halo PairsComments: Found significant mistakes in our resultsSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [114] arXiv:2005.12336 (replaced) [pdf]
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Title: Exploration of the outer solar system with fast and small sailcraftAuthors: Slava G. Turyshev, Peter Klupar, Abraham Loeb, Zachary Manchester, Kevin Parkin, Edward Witten, S. Pete WordenComments: A White Paper to the National Academy of Sciences Planetary Science and Astrobiology Decadal Survey 2023-2032. 13 pages, 5 figures and 2 tablesSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc)
- [115] arXiv:2005.14667 (replaced) [pdf, other]
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Title: Constraints on dark matter-nucleon effective couplings in the presence of kinematically distinct halo substructures using the DEAP-3600 detectorAuthors: P. Adhikari, R. Ajaj, C. E. Bina, W. Bonivento, M. G. Boulay, M. Cadeddu, B. Cai, M. Cárdenas-Montes, S. Cavuoti, Y. Chen, B. T. Cleveland, J. M. Corning, S. Daugherty, P. DelGobbo, P. Di Stefano, L. Doria, M. Dunford, A. Erlandson, S. S. Farahani, N. Fatemighomi, G. Fiorillo, D. Gallacher, E. A. Garcés, P. García Abia, S. Garg, P. Giampa, D. Goeldi, P. Gorel, K. Graham, A. Grobov, A. L. Hallin, M. Hamstra, T. Hugues, A. Ilyasov, A. Joy, B. Jigmeddorj, C. J. Jillings, O. Kamaev, G. Kaur, A. Kemp, I. Kochanek, M. Kuźniak, M. Lai, S. Langrock, B. Lehnert, N. Levashko, X. Li, O. Litvinov, J. Lock, G. Longo, I. Machulin, A. B. McDonald, T. McElroy, J. B. McLaughlin, C. Mielnichuk, J. Monroe, G. Oliviéro, S. Pal, S. J. M. Peeters, V. Pesudo, M.-C. Piro, T. R. Pollmann, et al. (22 additional authors not shown)Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph)
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