Astrophysics
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New submissions for Thu, 28 Nov 19
- [1] arXiv:1911.11767 [pdf, other]
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Title: When a Period Is Not a Full Stop: Light Curve Structure Reveals Fundamental Parameters of Cepheid and RR Lyrae StarsComments: Accepted for publication in MNRAS. Source code available at this https URLSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Instrumentation and Methods for Astrophysics (astro-ph.IM); Machine Learning (cs.LG)
The period of pulsation and the structure of the light curve for Cepheid and RR Lyrae variables depend on the fundamental parameters of the star: mass, radius, luminosity, and effective temperature. Here we train artificial neural networks on theoretical pulsation models to predict the fundamental parameters of these stars based on their period and light curve structure. We find significant improvements to estimates of these parameters made using light curve structure and period over estimates made using only the period. Given that the models are able to reproduce most observables, we find that the fundamental parameters of these stars can be estimated up to 60% more accurately when light curve structure is taken into consideration. We quantify which aspects of light curve structure are most important in determining fundamental parameters, and find for example that the second Fourier amplitude component of RR Lyrae light curves is even more important than period in determining the effective temperature of the star. We apply this analysis to observations of hundreds Cepheids in the Large Magellanic Cloud and thousands of RR Lyrae in the Magellanic Clouds and Galactic bulge to produce catalogs of estimated masses, radii, luminosities, and other parameters of these stars. As an example application, we estimate Wesenheit indices and use those to derive distance moduli to the Magellanic Clouds of $\mu_{\text{LMC},\text{CEP}} = 18.688 \pm 0.093$, $\mu_{\text{LMC},\text{RRL}} = 18.52 \pm 0.14$, and $\mu_{\text{SMC},\text{RRL}} = 18.88 \pm 0.17$ mag.
- [2] arXiv:1911.11769 [pdf, other]
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Title: The influence of stellar objects mass distribution on their gravitational fieldsComments: 21 pages, 8 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We study theoretically the influence of the astronomical objects masses randomness on the distribution function of their gravitational fields. We have shown that mass randomness does not change the non-Gaussian character of the gravitational fields distribution. At the same time, our results show that mass distribution alters the dependencies of the mean angular momenta of galaxies and clusters on their richness. The specific form of above dependence is determined by the interplay of mass distribution and different assumptions made about cluster morphology. We trace the influence of masses distribution on the time evolution of stellar objects angular momenta in CDM and $\Lambda$CDM models. We also compare our theoretical predictions with results derived both form observational data and numerical simulations.
- [3] arXiv:1911.11777 [pdf, other]
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Title: Extra-galactic jets: a hard X-ray viewAuthors: Gabriele Ghisellini (INAF - OA Brera)Comments: 6 paged, 6 figures, invited paper at the: "12th INTEGRAL conference" - Geneve, Feb. 2019Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Extragalactic jets are the most powerful persistent sources of the universe. Those pointing at us are called blazars. Their relativistically boosted emission extends from radio frequencies to TeV energies. They are also suspected to be the sources of energetic neutrinos and high energies cosmic rays. The study of their overall spectrum indicates that most of the emission of powerful blazars is in hard X-rays or in soft gamma-rays. In this band we can find the most powerful jets, visible also at high redshifts. It is found that the jet power is linked to the accretion luminosity, and exceeds it, especially if they produce energetic neutrinos, that require the presence of ultrarelativistic protons.
- [4] arXiv:1911.11778 [pdf, other]
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Title: SPECULATOR: Emulating stellar population synthesis for fast and accurate galaxy spectra and photometryAuthors: Justin Alsing, Hiranya Peiris, Joel Leja, ChangHoon Hahn, Rita Tojeiro, Daniel Mortlock, Boris Leistedt, Benjamin D. Johnson, Charlie ConroyComments: 15 pages, 9 figures, submitted to ApJSSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Astrophysics of Galaxies (astro-ph.GA)
We present \textsc{speculator} -- a fast, accurate, and flexible framework for emulating stellar population synthesis (SPS) models for predicting galaxy spectra and photometry. For emulating spectra, we use principal component analysis to construct a set of basis functions, and neural networks to learn the basis coefficients as a function of the SPS model parameters. For photometry, we parameterize the magnitudes (for the filters of interest) as a function of SPS parameters by a neural network. The resulting emulators are able to predict spectra and photometry under both simple and complicated SPS model parameterizations to percent-level accuracy, giving a factor of $10^3$--$10^4$ speed up over direct SPS computation. They have readily-computable derivatives, making them amenable to gradient-based inference and optimization methods. The emulators are also straightforward to call from a GPU, giving an additional order-of-magnitude speed-up. Rapid SPS computations delivered by emulation offers a massive reduction in the computational resources required to infer the physical properties of galaxies from observed spectra or photometry and simulate galaxy populations under SPS models, whilst maintaining the accuracy required for a range of applications.
- [5] arXiv:1911.11782 [pdf, other]
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Title: Living with Neighbors. II. Statistical Analysis of Flybys and Mergers of Dark Matter Halos in Cosmological SimulationsComments: 21 pages, 12 figures, and 1 table, accepted for publication in ApJSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We present a statistical analysis of flybys of dark matter halos compared to mergers using cosmological $N$-body simulations. We mainly focus on gravitationally interacting target halos with mass of $10^{10.8}-10^{13.0}h^{-1}M_{\odot}$, and their neighbors are counted only when the mass ratio is 1:3$-$3:1 and the distance is less than the sum of the virial radii of target and neighbor. The neighbors are divided into the flyby or merger samples if the pair's total energy is greater or smaller, respectively, than the capture criterion with consideration of dynamical friction. The main results are as follows: (a) The flyby fraction increases by up to a factor of 50 with decreasing halo mass and by up to a factor of 400 with increasing large-scale density, while the merger fraction does not show any significant dependencies on these two parameters; (b) The redshift evolution of the flyby fraction is twofold, increasing with redshift at $0<z<1$ and remaining constant at $z>1$, while the merger fraction increases monotonically with redshift at $z=0\sim4$; (c) The multiple interactions with two or more neighbors are on average flyby-dominated, and their fraction has a mass and environment dependence similar to that for the flyby fraction; (d) Given that flybys substantially outnumber mergers toward $z=0$ (by a factor of five) and the multiple interactions are flyby-dominated, the flyby's contribution to galactic evolution is stronger than ever at the present epoch, especially for less massive halos and in the higher density environment. We propose a scenario that connects the evolution of the flyby and merger fractions to the hierarchical structure formation process.
- [6] arXiv:1911.11783 [pdf, other]
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Title: Probing delayed-end reionization histories with the 21cm-LAE cross-power spectrumAuthors: Lewis H. Weinberger (IoA, Cambridge), Girish Kulkarni (TIFR, Mumbai), Martin G. Haehnelt (IoA, Cambridge)Comments: 15 pages, 9 figures, 2 tables, 2 appendices. Submitted to MNRASSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)
We model the 21-cm signal and LAE population evolution during the epoch of reionization in order to predict the 21cm-LAE cross-power spectrum. We employ high-dynamic-range simulations of the IGM to create models that are consistent with constraints from the CMB, Lyman-$\alpha$ forest and LAE population statistics. Using these models we consider the evolution of the cross-power spectrum for a selection of realistic reionization histories and predict the sensitivity of current and upcoming surveys to measuring this signal. We find that the imprint of a delayed-end to reionization can be observed by future surveys, and that strong constraints can be placed on the progression of reionization as late as $z=5.7$ using a Subaru-SKA survey. We make predictions for the signal-to-noise ratios achievable by combinations of Subaru/PFS with the MWA, LOFAR, HERA and SKA interferometers. We find that a Subaru-SKA survey could measure the cross-power spectrum for a late reionization at $z=6.6$ with a total signal-to-noise greater than 5, making it possible to constrain both the timing and bubble size at the end of reionization. Furthermore, we find that expanding the current Subaru/PFS survey area and depth by a factor of three would double the total signal-to-noise.
- [7] arXiv:1911.11785 [pdf, ps, other]
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Title: The halo mass function in alternative dark matter modelsAuthors: M. R. Lovell (University of Iceland)Comments: 4 pages, 3 figures, to be submitted to MNRAS letters. Email: lovell@hi.isSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
The claimed detection of large amounts of substructure in lensing flux anomalies, and in Milky Way stellar stream gaps statistics, has lead to a step change in constraints on simple warm dark matter models. In this study we compute predictions for the halo mass function both for these simple models and also for comprehensive particle physics models of sterile neutrinos and dark acoustic oscillations. We show that the mass function fit of Lovell et al. underestimates the number of haloes less massive than the half-mode mass, $M_\mathrm{hm}$, by a factor of 2, relative to the extended Press-Schechter (EPS) method. The alternative approach of applying EPS to the Viel et al. matter power spectrum fit instead suggests good agreement at $M_\mathrm{hm}$ relative to the comprehensive model matter power spectra results, although the number of haloes with mass $<M_\mathrm{hm}$ is still suppressed due to the absence of small scale power in the fitting function. Overall, we find that the number of dark matter haloes with masses $<10^{8}M_\mathrm{sun}$ predicted by competitive particle physics models is underestimated by a factor of $\sim2$ when applying popular fitting functions, although careful studies that follow the stripping and destruction of subhaloes will be required in order to draw robust conclusions.
- [8] arXiv:1911.11786 [pdf, other]
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Title: High accuracy on $H_0$ constraints from gravitational wave lensing eventsComments: 10 pages, 3 figures, comments are welcomedSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
In light of the newly opened and rapidly growing GW window in multi-messenger astronomy, in order to fully take advantage of the new opportunities we are provided with, new ideas are required for a better and deeper employ of the state-of-the-art probes we handle. Following this goal, here we suggest a method to constrain the cosmological background, and the Hubble constant in particular, by future observations of gravitationally lensed radiation emitted by a single source in both the gravitational wave and the electromagnetic regimes. The lensing of the gravitational wave radiation, in fact, can leave a clear imprinting in the corresponding waveform, and we want to analyze if such kind of measurements can be successfully employed to better constrain the cosmological background. Thus, by making use of wave optics for the gravitational wave lensed signal, and of standard geometrical optics approximation for the electromagnetic one, we study the impact of different cosmological parameters on the value of the arrival time delay due to gravitational lensing, given specific GW frequencies, mass models of the lens, and redshifts and positions (with respect to the lens) of the source. Although the rate of lensing of gravitational waves is expected to be low, we show that even one single event could provide us with an uncertainty on $H_0$ comparable with present independent probes in a "pessimistic" scenario (with a pulsar population similar to present Pulsar Timing Array state), and of two orders smaller in an optimistic one (with a number of observed pulsars as large as that expected from the Square Kilometer Array). Thus, its role in the solution of the Hubble tension could be decisive.
- [9] arXiv:1911.11802 [pdf, ps, other]
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Title: Photometric light curve solutions of three ultra-short period eclipsing binariesComments: 11 pages, 7 figures, accepted for publications in Research in Astronomy & AstrophysicsSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
We present the results of our study of the eclipsing binary systems CSS J112237.1+395219, LINEAR 1286561 and LINEAR 2602707 based on new CCD $B$, $V$, $R_c$ and $I_c$ complete light curves. The ultra-short period nature of the stars \citep{Drake2014} is confirmed and the system's periods are revised. The light curves were modelled using the 2005 version of the Wilson-Devinney code. When necessary, cool spots on the surface of the primary component were introduced to account for asymmetries in the light curves. As a result, we found that CSS J112237.1+395219 is a W UMa type contact binary system belonging to W subclass with a mass ratio of $q=1.61$ and a shallow degree of contact of 14.8\% where the primary component is hotter than the secondary one by $500K$. LINEAR 1286561 and LINEAR 2602707 are detached binary systems with mass ratios $q=3.467$ and $q=0.987$ respectively. These detached systems are low-mass M-type eclipsing binaries of similar temperatures. The marginal contact, the fill-out factor and the temperature difference between components of CSS J112237.1+395219 suggest that this system may be at a key evolutionary state predicted by the Thermal Relaxation Oscillation theory (TRO). From the estimated absolute parameters we conclude that our systems share common properties with others ultra-short period binaries.
- [10] arXiv:1911.11804 [pdf, other]
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Title: A seismic scaling relation for stellar age II: The red giant branchAuthors: Earl Patrick BellingerComments: 5 pages, 4 figures. Accepted for publication in MNRAS Letters. Source code providedSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Owing to their simplicity and ease of application, seismic scaling relations are widely used to determine the properties of stars exhibiting solar-like oscillations, such as solar twins and red giants. So far, no seismic scaling relations for determining the ages of red giant stars have been developed. Such relations would be desirable for galactic archaeology, which uses stellar ages to map the history of the Milky Way. The ages of red giants must instead be estimated with reference to grids of theoretical stellar models, which can be computationally intensive. Here I present an exhaustive search for scaling age relations involving different combinations of observable quantities. The candidate scaling relations are calibrated and tested using more than 1,000 red giant stars whose ages were obtained via grid-based modeling. I report multiple high-quality scaling relations for red giant branch stars, the best of which are shown to be approximately as accurate as grid-based modeling with typical uncertainties of 15%. Additionally, I present new scaling mass and radius relations for red giants as well.
- [11] arXiv:1911.11809 [pdf, other]
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Title: Constraints on Neutrino Emission from Nearby Galaxies Using the 2MASS Redshift Survey and IceCubeAuthors: IceCube Collaboration: M. G. Aartsen, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, C. Alispach, K. Andeen, T. Anderson, I. Ansseau, G. Anton, C. Argüelles, J. Auffenberg, S. Axani, P. Backes, H. Bagherpour, X. Bai, A. Balagopal V., A. Barbano, S. W. Barwick, B. Bastian, V. Baum, S. Baur, R. Bay, J. J. Beatty, K.-H. Becker, J. Becker Tjus, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, C. Bohm, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, J. Bourbeau, F. Bradascio, J. Braun, S. Bron, J. Brostean-Kaiser, A. Burgman, J. Buscher, R. S. Busse, T. Carver, C. Chen, E. Cheung, D. Chirkin, S. Choi, K. Clark, L. Classen, A. Coleman, G. H. Collin, J. M. Conrad, P. Coppin, P. Correa, D. F. Cowen, R. Cross, P. Dave, C. De Clercq, et al. (293 additional authors not shown)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
The distribution of galaxies within the local universe is characterized by anisotropic features. Observatories searching for the production sites of astrophysical neutrinos can take advantage of these features to establish directional correlations between a neutrino dataset and overdensities in the galaxy distribution in the sky. The results of two correlation searches between a seven-year time-integrated neutrino dataset from the IceCube Neutrino Observatory, and the 2MASS Redshift Survey (2MRS) catalog are presented here. The first analysis searches for neutrinos produced via interactions between diffuse intergalactic Ultra-High Energy Cosmic Rays (UHECRs) and the matter contained within galaxies. The second analysis searches for low-luminosity sources within the local universe, which would produce subthreshold multiplets in the IceCube dataset that directionally correlate with galaxy distribution. No significant correlations were observed in either analyses. Constraints are presented on the flux of neutrinos originating within the local universe through diffuse intergalactic UHECR interactions, as well as on the density of standard candle sources of neutrinos at low luminosities.
- [12] arXiv:1911.11812 [pdf, other]
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Title: Asteroseismic Signature of a Large Active RegionComments: Accepted for publication in Frontiers in Astronomy and Space SciencesSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
Axisymmetric magnetic activity on the Sun and Sun-like stars increases the frequencies of the modes of acoustic oscillation. However, it is unclear how a corotating patch of activity affects the oscillations, since such a perturbation is unsteady in the frame of the observer. In this paper we qualitatively describe the asteroseismic signature of a large active region in the power spectrum of the dipole and quadrupole p modes. In the corotating frame of the active region, the perturbations due to (differential) rotation and the active region completely lift the $(2\ell + 1)$-fold azimuthal degeneracy of the frequency spectrum of modes with harmonic degree $\ell$. In the frame of the observer, the unsteady nature of the perturbation leads to the appearance of $(2\ell+1)^2$ peaks in the power spectrum of a multiplet. These peaks blend into each other to form asymmetric line profiles. In the limit of a small active region, we approximate the power spectrum of a multiplet in terms of $2\times(2\ell+1)$ peaks, whose amplitudes and frequencies depend on the latitude of the active region and the inclination angle of the star's rotation axis. In order to check the results and to explore the nonlinear regime, we also perform numerical simulations using the 3D time-domain pseudo-spectral linear pulsation code GLASS.
- [13] arXiv:1911.11814 [pdf, other]
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Title: Imaging the 44 AU Kuiper Belt-analogue debris ring around HD 141569A with GPI polarimetryAuthors: J. S. Bruzzone, S. Metchev, G. Duchene, M. A. Millar-Blanchaer, R. Dong, J. J. Wang, J. R. Graham, J. Mazoyer, S. Wolff, S. M. Ammons, A. C. Schneider, A. Z. Greenbaum, B. C. Matthews, P. Arriaga, V. P. Bailey, T. Barman, J. Bulger, J. Chilcote, T. Cotten, R. J. De Rosa, R. Doyon, M. P. Fitzgerald, K. B. Follette, B. L. Gerard, S. J. Goodsell, P. Hibon, J. Hom, L.-W. Hung, P. Ingraham, P. Kalas, Q. Konopacky, J. E. Larkin, B. Macintosh, J. Maire, F. Marchis, C. Marois, K. M. Morzinski, E. L. Nielsen, R. Oppenheimer, D. Palmer, R. Patel, J. Patience, M. Perrin, L. Poyneer, L. Pueyo, A. Rajan, J. Rameau, F. T. Rantakyro, D. Savransky, A. Sivaramakrishnan, I. Song, R. Soummer, S. Thomas, J. K. Wallace, K. Ward-Duong, S. WiktorowiczComments: 16 pages, 8 figures, accepted at AJSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
We present the first polarimetric detection of the inner disk component around the pre-main sequence B9.5 star HD 141569A. Gemini Planet Imager H-band (1.65 micron) polarimetric differential imaging reveals the highest signal-to-noise ratio detection of this ring yet attained and traces structure inwards to 0.25" (28 AU at a distance of 111 pc). The radial polarized intensity image shows the east side of the disk, peaking in intensity at 0.40" (44 AU) and extending out to 0.9" (100 AU). There is a spiral arm-like enhancement to the south, reminiscent of the known spiral structures on the outer rings of the disk. The location of the spiral arm is coincident with 12CO J=3-2 emission detected by ALMA, and hints at a dynamically active inner circumstellar region. Our observations also show a portion of the middle dusty ring at ~220 AU known from previous observations of this system. We fit the polarized H-band emission with a continuum radiative transfer Mie model. Our best-fit model favors an optically thin disk with a minimum dust grain size close to the blow-out size for this system: evidence of on-going dust production in the inner reaches of the disk. The thermal emission from this model accounts for virtually all of the far-infrared and millimeter flux from the entire HD 141569A disk, in agreement with the lack of ALMA continuum and CO emission beyond ~100 AU. A remaining 8-30 micron thermal excess a factor of ~2 above our model argues for a yet-unresolved warm innermost 5-15 AU component of the disk.
- [14] arXiv:1911.11816 [pdf, other]
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Title: Laboratory astrophysics: key to understanding the UniverseAuthors: Ewine F. van Dishoeck (Leiden Observatory, Leiden University, the Netherlands and MPE, Garching, Germany)Comments: 12 pages, 6 figures, to be published in the proceedings of IAU Symposium 350 "Laboratory Astrophysics: from Observations to Interpretation", ed. F. Salama et alSubjects: Astrophysics of Galaxies (astro-ph.GA); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
This brief overview stresses the importance of laboratory data and theory in analyzing astronomical observations and understanding the physical and chemical processes that drive the astrophysical phenomena in our Universe. This includes basic atomic and molecular data such as spectroscopy and collisional rate coefficients, but also an improved understanding of nuclear, plasma and particle physics, as well as reactions and photoprocesses in the gaseous and solid state that lead to chemical complexity and building blocks for life. Systematic laboratory collision experiments have provided detailed insight into the steps that produce pebbles, bricks and ultimately planetesimals starting from sub-$\mu$m-sized grains. Sample return missions and meteoritic studies benefit from increasingly sophisticated laboratory machines to analyze materials and provide compositional images on nanometer scales. Prioritization of future data requirements will be needed to cope with the increasing data streams from a diverse range of future astronomical facilities within a constrained laboratory astrophysics budget.
- [15] arXiv:1911.11826 [pdf, other]
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Title: Point Source Detection with Fully-Convolutional Networks: Performance in Realistic SimulationsAuthors: L. Bonavera, S. L. Suarez Gomez, J. González-Nuevo, J. D. Santos, M. L. Sanchez, R. Muñiz, F. J. de CosComments: 9 pages, 4 figures, submitted to Astronomy & AstrophysicsSubjects: Astrophysics of Galaxies (astro-ph.GA)
Point Sources (PS) are one of the main contaminants to the recovery of Cosmic Microwave Background (CMB) signal at small scales, and their careful detection will be important for the next generation of CMB experiments like CORE. We want to develop a method based on Fully Convolutional Networks (FCN) to detect PS in realistic simulations, the Point Source Image Detection Network (PoSeIDoN), and compare its performance against one of the most used PS detection method in this context, the Mexican Hat wavelet 2 (MHW2). The frequencies for our analysis are the 143, 217 and 353 GHz Planck channels. We produce PS realistic simulations at each frequency including possible contaminating signals as CMB, Cosmic Infrared Background, Galactic thermal emission and instrumental noise. We first produce a set of training simulations at 217 GHz. Then we apply both the trained FCN and the MHW2 to recover the PS in the validating simulations at all the frequencies, comparing the results by estimating the reliability, completeness and flux density estimation accuracy. In the extragalactic region with a 30 deg galactic cut, the FCN successfully recover PS with 90% of completeness corresponding to 300, 139 and 227 mJy for 143, 217 and 353 GHz. On the same validation simulations, the MHW2 with a 4sigma flux density detection limit, recover PS till 298, 173 and 227 mJy at the 90% completeness. In all cases the FCN produce a much lower number of spurious sources with respect the MHW2. As expected, the results on spurious sources for both techniques worsen when increasing the frequency or reducing the galactic cut to 10 deg. Our results suggests that FCN are a very promising approach to detect PS using data from CMB experiments, providing overall better results with respect to the more usual filtering approaches.
- [16] arXiv:1911.11829 [pdf, other]
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Title: Deciphering the Nature of the Pulsar Wind Nebula CTB 87 with XMM-NewtonAuthors: Benson Guest, Samar Safi-Harb, Austin MacMaster, Roland Kothes, Barbara Olmi, Elena Amato, Niccolo Bucciantini, Zaven ArzoumanianComments: 9 pages, 10 figures. Accepted for publication in MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
CTB 87 (G74.9+1.2) is an evolved supernova remnant (SNR) which hosts a peculiar pulsar wind nebula (PWN). The X-ray peak is offset from that observed in radio and lies towards the edge of the radio nebula. The putative pulsar, CXOU~J201609.2+371110, was first resolved with \textit{Chandra} and is surrounded by a compact and a more extended X-ray nebula. Here we use a deep {\textit{XMM-Newton}} observation to examine the morphology and evolutionary stage of the PWN and to search for thermal emission expected from a supernova shell or reverse shock interaction with supernova ejecta. We do not find evidence of thermal X-ray emission from the SNR and place an upper limit on the electron density of 0.05~cm$^{-3}$ for a plasma temperature $kT\sim 0.8$ keV. The morphology and spectral properties are consistent with a $\sim$20~kyr-old relic PWN expanding into a stellar wind-blown bubble. We also present the first X-ray spectral index map from the PWN and show that we can reproduce its morphology by means of 2D axisymmetric relativistic hydrodynamical simulations.
- [17] arXiv:1911.11831 [pdf, other]
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Title: Efficient Gravitational-wave Glitch Identification from Environmental Data Through Machine LearningAuthors: Robert E. Colgan, K. Rainer Corley, Yenson Lau, Imre Bartos, John N. Wright, Zsuzsa Marka, Szabolcs MarkaSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); General Relativity and Quantum Cosmology (gr-qc)
The LIGO observatories detect gravitational waves through monitoring changes in the detectors' length down to below $10^{-19}$\,$m/\sqrt{Hz}$ variation---a small fraction of the size of the atoms that make up the detector. To achieve this sensitivity, the detector and its environment need to be closely monitored. Beyond the gravitational wave data stream, LIGO continuously records hundreds of thousands of channels of environmental and instrumental data in order to monitor possible minuscule variations that contribute to the detector noise. A particularly challenging issue is the appearance in the gravitational wave signal of brief, loud noise artifacts called "glitches," which are environmental or instrumental in origin but can mimic true gravitational waves and therefore hinder sensitivity. Currently they are identified by analysis of the gravitational wave data stream. Here we present a machine learning approach that can identify glitches by monitoring \textit{all} environmental and detector data channels, a task that has not previously been pursued due to its scale and the number of degrees of freedom within gravitational-wave detectors. The presented method is capable of reducing the gravitational-wave detector networks' false alarm rate and improving the LIGO instruments, consequently enhancing detection confidence.
- [18] arXiv:1911.11836 [pdf, other]
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Title: Testing Modified Gravity with Acceleration Relations in the Milky WayComments: 7 pages, 6 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
The dynamical mass of galaxies and the Newtonian acceleration generated from the baryons have been found to be strongly correlated. This correlation is known as 'Mass-Discrepancy Acceleration Relation' (MDAR). Further investigations have revealed a tighter relation - 'Radial Acceleration Relation' (RAR) - between the observed total acceleration and the (Newtonian) acceleration produced by the baryons. So far modified gravity theories have remained more successful than $\Lambda$CDM to explain these relations. However, a recent investigation has pointed out that, when RAR is expressed as a difference between the observed acceleration and the expected Newtonian acceleration due to baryons (which has been called the 'Halo acceleration relation or HAR'), it provides a stronger test for modified gravity theories and dark matter hypothesis. Extending our previous work \citep{kt2018}, we present a case study of modified gravity theories, in particular Weyl conformal gravity and Modified Newtonian Dynamics (MOND), using recent inferred acceleration data for the Milky Way. We investigate how well these theories of gravity and the RAR scaling law can explain the current observation.
- [19] arXiv:1911.11841 [pdf, other]
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Title: Cross Correlation of the Extragalactic Gamma-ray Background with Thermal Sunyaev-Zel'dovich Effect in the Cosmic Microwave BackgroundComments: 16 pages, 13 figures, 1 tableSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE)
Cosmic rays in galaxy clusters are unique probes of energetic processes operating with large-scale structures in the Universe. Precise measurements of cosmic rays in galaxy clusters are essential for improving our understanding of non-thermal components in the intracluster-medium (ICM) as well as the accuracy of cluster mass estimates in cosmological analyses. In this paper, we perform a cross-correlation analysis with the extragalactic gamma-ray background and the thermal Sunyaev-Zel'dovich (tSZ) effect in the cosmic microwave background. The expected cross-correlation signal would contain rich information about the cosmic-ray-induced gamma-ray emission in the most massive galaxy clusters at $z\sim0.1-0.2$. We analyze the gamma-ray background map with 8 years of data taken by the Large Area Telescope onboard Fermi satellite and the publicly available tSZ map by Planck. Our measurements are consistent with a null detection, but a weak correlation is found at angular scales of $\sim10$ arcmins. The null detection in our cross-correlation analysis enables us to put the tightest constraint of the acceleration efficiency of cosmic ray protons at shocks. We find the acceleration efficiency must be below $2.4\%$ with a $2\sigma$ confidence level when the hydrostatic mass bias of clusters is assumed to be $30\%$, while our result is less affected by the assumed value of the hydrostatic mass bias. Our constraint implies that the non-thermal cosmic-ray pressure in the ICM can introduce only a $\le1\%$ level of the hydrostatic mass bias, highlighting that the cosmic ray is incompatible with the mass bias inferred by the Planck analyses. Finally, we discuss future detectability prospects of cosmic-ray-induced gamma rays from the Perseus cluster for the Cherenkov Telescope Array.
- [20] arXiv:1911.11848 [pdf, other]
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Title: Is the Hubble diagram of quasars in tension with concordance cosmology?Comments: 5 pages, 2 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Recently Risaliti \& Lusso [Nature Astron. 3 (2019) 3 272] reported new measurements of the expansion rate of the Universe by constructing the Hubble diagram of 1598 quasars in the redshift range $0.5<z<5.5$. It is claimed a $4\sigma$ tension with the standard concordance $\Lambda$CDM concerning both the fractionary matter density $\Omega_{m0}$ and the dark energy equation of state parameter $w_{de}$ standard values. In this work we promote an independent analysis of the same data set using a model-independent estimator for cosmic acceleration. Our results corroborate that the source of such tension can be related to the $\Omega_{m0}$ value with a reasonable indication of a higher $\Omega_{m0}$ value ($\Omega_{m0} \gtrsim 0.4$). On the other hand, we find that the role played by $w_{de}$ on the claimed tension is weak. We also discuss the use of this estimator as a "quality tool" to test the robustness of Hubble diagrams. We conclude claiming that the Quasars data can not yet be seen as a reliable cosmological tool since they can not even state the universe experienced an accelerated expansion phase.
- [21] arXiv:1911.11849 [pdf]
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Title: The Distinction Between Thermal Nonequilibrium and Thermal InstabilityAuthors: James A. KlimchukComments: accepted by Solar Physics 16 pages, 1 figureSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
For some forms of steady heating, coronal loops are in a state of thermal nonequilibrium and evolve in a manner that includes accelerated cooling, often resulting in the formation of a cold condensation. This is frequently confused with thermal instability, but the two are in fact fundamentally different. We explain the distinction and discuss situations where they may be interconnected. Large-amplitude perturbations, perhaps associated with MHD waves, likely play a role in explaining phenomena that have been attributed to thermal nonequilibrium but also seem to require cross-field communication.
- [22] arXiv:1911.11860 [pdf, other]
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Title: Charge exchange emission and cold clumps in multi-phase galactic outflowsAuthors: Kinwah Wu, Kaye Jiale Li, Ellis R. Owen, Li Ji, Shuinai Zhang, Graziella Branduardi-RaymontComments: 17 pages, 6 figures; accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
Large-scale outflows from starburst galaxies are multi-phase, multi-component fluids. Charge-exchange lines which originate from the interfacing surface between the neutral and ionised components are a useful diagnostic of the cold dense structures in the galactic outflow. From the charge-exchange lines observed in the nearby starburst galaxy M82, we conduct surface-to-volume analyses and deduce that the cold dense clumps in its galactic outflow have flattened shapes, resembling a hamburger or a pancake morphology rather than elongated shapes. The observed filamentary H$\alpha$ features are therefore not prime charge-exchange line emitters. They are stripped material torn from the slow moving dense clumps by the faster moving ionised fluid which are subsequently warmed and stretched into elongated shapes. Our findings are consistent with numerical simulations which have shown that cold dense clumps in galactic outflows can be compressed by ram pressure, and also progressively ablated and stripped before complete disintegration. We have shown that some clumps could survive their passage along a galactic outflow. These are advected into the circumgalactic environment, where their remnants would seed condensation of the circumgalactic medium to form new clumps. The infall of these new clumps back into the galaxy and their subsequent re-entrainment into the galactic outflow form a loop process of galactic material recycling.
- [23] arXiv:1911.11877 [pdf, other]
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Title: Mass models of gas-rich void dwarf galaxiesComments: Accepted for publication in MNRAS, 24 pages, 58 figures, and 6 tablesSubjects: Astrophysics of Galaxies (astro-ph.GA)
We construct mass models of eight gas rich dwarf galaxies that lie in the Lynx-Cancer void. From NFW fits to the dark matter halo profile, we find that the concentration parameters of halos of void dwarf galaxies are similar to those of dwarf galaxies in normal density regions. We also measure the slope of the central dark matter density profiles, obtained by converting the rotation curves derived using 3-D (\fat) and 2-D (ROTCUR) tilted ring fitting routines, into mass densities. We find that the average slope ($\alpha = -1.39 \pm 0.19$), obtained from 3-D fitting is consistent with that expected from an NFW profile. On the other hand, the average slope measured using the 2-D approach is closer to what would be expected for an isothermal profile. This suggests that systematic effects in velocity field analysis have a significant effect on the slope of the central dark matter density profiles. Given the modest number of galaxies we use for our analysis, it is important to check these results using a larger sample.
- [24] arXiv:1911.11887 [pdf, other]
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Title: The ALMaQUEST Survey: III. Scatter in the resolved star forming main sequence is primarily due to variations in star formation efficiencyAuthors: Sara L. Ellison, Mallory D. Thorp, Lihwai Lin, Hsi-An Pan, Asa F. L. Bluck, Jillian M. Scudder, Hossen Teimoorinia, Sebastian F. Sanchez, Mark SargentComments: Accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
Using a sample of 11,478 spaxels in 34 galaxies with molecular gas, star formation and stellar maps taken from the ALMA-MaNGA QUEnching and STar formation (ALMaQUEST) survey, we investigate the parameters that correlate with variations in star formation rates on kpc scales. We use a combination of correlation statistics and an artificial neural network to quantify the parameters that drive both the absolute star formation rate surface density (Sigma_SFR), as well as its scatter around the resolved star forming main sequence (Delta Sigma_SFR). We find that Sigma_SFR is primarily regulated by molecular gas surface density (Sigma_H2) with a secondary dependence on stellar mass surface density (Sigma_*), as expected from an `extended Kennicutt-Schmidt relation'. However, Delta Sigma_SFR is driven primarily by changes in star formation efficiency (SFE), with variations in gas fraction playing a secondary role. Taken together, our results demonstrate that whilst the absolute rate of star formation is primarily set by the amount of molecular gas, the variation of star formation rate above and below the resolved star forming main sequence (on kpc scales) is primarily due to changes in SFE.
- [25] arXiv:1911.11902 [pdf, other]
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Title: Design of a testbed for the study of system interference in space CMB polarimetryAuthors: Tommaso Ghigna, Tomotake Matsumura, Masashi Hazumi, Samantha Lynn Stever, Yuki Sakurai, Nobuhiko Katayama, Aritoki Suzuki, Benjamin Westbrook, Adrian LeeComments: 7 pages, 4 figures, 2 tables, submitted to the Journal of Low Temperature Physics: LTD18 Special EditionSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Instrumentation and Detectors (physics.ins-det)
LiteBIRD is a proposed JAXA satellite mission to measure the CMB B-mode polarization with unprecedented sensitivity ($\sigma_r\sim 0.001$). To achieve this goal, $4676$ state-of-the-art TES bolometers will observe the whole sky for 3 years from L2. These detectors, as well as the SQUID readout, are extremely susceptible to EMI and other instrumental disturbances e.g. static magnetic field and vibration. As a result, careful analysis of the interference between the detector system and the rest of the telescope instruments is essential. This study is particularly important during the early phase of the project, in order to address potential problems before the final assembly of the whole instrument. We report our plan for the preparation of a cryogenic testbed to study the interaction between the detectors and other subsystems, especially a polarization modulator unit consisting of a magnetically-rotating half wave plate. We also present the requirements, current status and preliminary results.
- [26] arXiv:1911.11911 [pdf, other]
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Title: The Andromeda System: A new orbital history and its implicationsComments: 12 pagesSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We revisit the orbital history of the Triangulum galaxy (M33) around the Andromeda galaxy (M31) in view of the recent Gaia Data Release 2 proper motion measurements for both Local Group galaxies. Earlier studies consider highly idealized dynamical friction, but neglect the effects of dynamical mass loss. We show the latter process to be important using orbit integrations and N-body simulations, which are mutually consistent. Contrary to previous claims that only a `first infall' is supported by the data, we find an orbital solution that brings these galaxies to within ~50 kpc of each other in the past, i.e. ~6.5 Gyr ago. We explore the implications of this finding using a N-body/hydrodynamical simulation to model the infall of M33 into M31 with a focus on the origin of two prominent features of this system: 1) M31's metal-rich Giant Stellar Stream; and 2) the M31-M33 HI filament. We find that the tidal interaction does not produce a stellar structure reminiscent of the stellar stream that survives up to the present day. The observed, outer disc warp in M33 may well be a relic of this past interaction. Similarly, the HI filament is likely a fossil structure dating back to the time of the ancient encounter between these galaxies. Our model implies the existence of a much larger, diffuse gas stream, the `Triangulum stream', that extends from M33 away from M31. We anticipate upcoming observations with the recently commissioned, Five-hundred-meter Aperture Spherical radio Telescope (FAST) that will target the putative stream in its first years of operation.
- [27] arXiv:1911.11912 [pdf, other]
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Title: The nearby luminous transient AT2018cow: a magnetar formed in a sub-relativistically expanding non-jetted explosionComments: 12 pages, 4 figures, 4 tables. Submitted to ApJ LettersSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
The fast-rising blue optical transient AT2018cow indicated unusual early phase characteristics unlike relatively better studied explosive transients. Its afterglow may be produced by either a relativistically beamed (jetted) or intrinsically luminous (non-jetted) ejecta and carries observational signatures of the progenitor and environment. High resolution monitoring can distinguish between these scenarios and clarify the progenitor nature. We present very long baseline interferometry (VLBI) observations of AT2018cow at 5 GHz involving 21 radio telescopes from the European VLBI Network with five sessions spanning ~ 1 year. With an astrometric precision up to 25 micro-arcseconds per epoch, the rapidly fading compact mas scale source is found to be non-jetted with a proper motion of <= 0.15 mas/yr (0.14 c). This and a dense (number density ~ 10^4 - 10^5/cm^3) magnetized environment (magnetic field strength >= 0.84 G) are characteristic of a newly formed magnetar driven central engine, originating in the successful explosion of a low-mass star.
- [28] arXiv:1911.11947 [pdf, other]
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Title: Beyond Limber: Efficient computation of angular power spectra for galaxy clustering and weak lensingComments: 22 pages + 2 appendices, 8 figures, to be submitted to JCAP, Code available at this https URLSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Angular two-point statistics of large-scale structure observables are important cosmological probes. To reach the high accuracy required by the statistical precision of future surveys, some of these statistics may need to be computed without the commonly employed Limber approximation; the exact computation however requires integration over Bessel functions, and a brute-force evaluation is slow to converge. We present a new method based on our generalized FFTLog algorithm for the efficient computation of angular power spectra beyond the Limber approximation. The new method significantly simplifies the calculation and improves the numerical speed and stability. It is easily extended to handle integrals involving derivatives of Bessel functions, making it equally applicable to numerically more challenging cases such as contributions from redshift-space distortions and Doppler effects. We implement our method for galaxy clustering and galaxy-galaxy lensing power spectra. We find that using the Limber approximation for galaxy clustering in future analyses like LSST Year 1 and DES Year 6 may cause significant biases in cosmological parameters, indicating that going beyond the Limber approximation is necessary for these analyses.
- [29] arXiv:1911.11953 [pdf, ps, other]
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Title: OGLE-2016-BLG-1227L: A Wide-separation Planet from a Very Short-timescale Microlensing EventAuthors: Cheongho Han, Andrzej Udalski, Andrew Gould, Michael D. Albrow, Sun-Ju Chung, Kyu-Ha Hwang, Youn Kil Jung, Chung-Uk Lee, Yoon-Hyun Ryu, In-Gu Shin, Yossi Shvartzvald, Jennifer C. Yee, Weicheng Zang, Sang-Mok Cha, Dong-Jin Kim, Hyoun-Woo Kim, Seung-Lee Kim, Dong-Joo Lee, Yongseok Lee, Byeong-Gon Park, Richard W. Pogge, M. James Jee, Doeon Kim, Chun-Hwey Kim, Woong-Tae Kim, Przemek Mróz, Michał K. Szymański, Jan Skowron, Radek Poleski, Igor Soszyński, Paweł Pietrukowicz, Szymon Kozłowski, Krzysztof UlaczykComments: 8 figures, 4 tablesSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
We present the analysis of the microlensing event OGLE-2016-BLG-1227. The light curve of this short-duration event appears to be a single-lens event affected by severe finite-source effects. Analysis of the light curve based on single-lens single-source (1L1S) modeling yields very small values of the event timescale, $t_{\rm E}\sim 3.5$ days, and the angular Einstein radius, $\theta_{\rm E}\sim 0.009$ mas, making the lens a candidate of a free-floating planet. Close inspection reveals that the 1L1S solution leaves small residuals with amplitude $\Delta I\lesssim 0.03$ mag. We find that the residuals are explained by the existence of an additional widely-separated heavier lens component, indicating that the lens is a wide-separation planetary system rather than a free-floating planet. From Bayesian analysis, it is estimated that the planet has a mass of $M_{\rm p} = 0.79^{+1.30}_{-0.39} M_{\rm J}$ and it is orbiting a low-mass host star with a mass of $M_{\rm host}=0.10^{+0.17}_{-0.05} M_\odot$ located with a projected separation of $a_\perp=3.4^{+2.1}_{-1.0}$ au. The planetary system is located in the Galactic bulge with a line-of-sight separation from the source star of $D_{\rm LS}=1.21^{+0.96}_{-0.63}$ kpc. The event shows that there are a range of deviations in the signatures of host stars for apparently isolated planetary lensing events and that it is possible to identify a host even when a deviation is subtle.
- [30] arXiv:1911.11954 [pdf, other]
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Title: The Pan-Pacific Planet Search. VIII. Complete results and the occurrence rate of planets around low-luminosity giantsAuthors: Robert A. Wittenmyer, R.P. Butler, Jonathan Horner, Jake Clark, C.G. Tinney, B.D. Carter, Liang Wang, John Asher Johnson, Michaela CollinsComments: Accepted for publication in MNRAS. Full text of tables A1 and A2 available from the lead author in exchange for advice on how to make MNRAS format long tables properlySubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Our knowledge of the populations and occurrence rates of planets orbiting evolved intermediate-mass stars lags behind that for solar-type stars by at least a decade. Some radial velocity surveys have targeted these low-luminosity giant stars, providing some insights into the properties of their planetary systems. Here we present the final data release of the Pan-Pacific Planet Search, a 5-year radial velocity survey using the 3.9m Anglo-Australian Telescope. We present 1293 precise radial velocity measurements for 129 stars, and highlight six potential substellar-mass companions which require additional observations to confirm. Correcting for the substantial incompleteness in the sample, we estimate the occurrence rate of giant planets orbiting low-luminosity giant stars to be approximately 7.8$^{+9.1}_{-3.3}$\%. This result is consistent with the frequency of such planets found to orbit main-sequence A-type stars, from which the PPPS stars have evolved.
- [31] arXiv:1911.11959 [pdf, other]
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Title: Characterising the Structure of Halo Merger Trees Using a Single Parameter: The Tree EntropyAuthors: Danail Obreschkow, Pascal J. Elahi, Claudia del P. Lagos, Rhys J. J. Poulton, Aaron D. LudlowComments: 20 pages, 16 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Combinatorics (math.CO)
Linking the properties of galaxies to the assembly history of their dark matter haloes is a central aim of galaxy evolution theory. This paper introduces a dimensionless parameter $s\in[0,1]$, the "tree entropy", to parametrise the geometry of a halo's entire mass assembly hierarchy, building on a generalisation of Shannon's information entropy. By construction, the minimum entropy ($s=0$) corresponds to smoothly assembled haloes without any mergers. In contrast, the highest entropy ($s=1$) represents haloes grown purely by equal-mass binary mergers. Using simulated merger trees extracted from the cosmological $N$-body simulation SURFS, we compute the natural distribution of $s$, a skewed bell curve peaking near $s=0.3$ for first generation haloes. This distribution exhibits weak dependences on halo mass $M$ and redshift $z$, which can be reduced to a single dependence of $\langle s\rangle$ on the relative peak height $\delta_{\rm c}/\sigma(M,z)$ in the matter perturbation field. By exploring the correlations between $s$ and global galaxy properties generated by the SHARK semi-analytic model, we find that $s$ contains a significant amount of information on the morphology of galaxies $-$ in fact more information than the spin, concentration and assembly time of the halo. Therefore, the tree entropy provides an information-rich link between galaxies and their dark matter haloes.
- [32] arXiv:1911.11975 [pdf, other]
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Title: Inclination Dependence of The Time-Lag -- Photon-Index Correlation in BHXRBs and its Explanation with a Simple Jet ModelAuthors: N. Kylafis (Univ of Crete, Inst. of Astrophysics-FORTH), P. Reig (Inst. of Astrophysics-FORTH, Univ of Crete)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Recently, we reported an observational correlation between a) the time-lag of the hard (9 - 15 keV) with respect to the soft (2 - 5 keV) X-ray photons in black-hole X-ray binaries (BHXRBs) and b) the power-law photon index $\Gamma$ of the X-ray spectrum. This was physically explained with a simple jet model, i.e., a model where the Comptonization (the Compton upscattering of soft photons) happens in the jet. Here, we report the inclination dependence of this correlation, which we also explain with our jet model. Photons that emerge at different polar angles from the jet axis have different spectra and different time-lags. Because of this, we can explain quantitatively the type-B QPOs of GX 339-4 as resulting from a precessing jet.
- [33] arXiv:1911.11989 [pdf, ps, other]
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Title: A wide star-black-hole binary system from radial-velocity measurementsAuthors: Jifeng Liu, Haotong Zhang, Andrew W. Howard, Zhongrui Bai, Youjun Lu, Roberto Soria, Stephen Justham, Xiangdong Li, Zheng Zheng, Tinggui Wang, Krzysztof Belczynski, Jorge Casares, Wei Zhang, Hailong Yuan, Yiqiao Dong, Yajuan Lei, Howard Isaacson, Song Wang, Yu Bai, Yong Shao, Qing Gao, Yilun Wang, Zexi Niu, Kaiming Cui, Chuanjie Zheng, Xiaoyong Mu, Lan Zhang, Wei Wang, Alexander Heger, Zhaoxiang Qi, Shilong Liao, Mario Lattanzi, Wei-Min Gu, Junfeng Wang, Jianfeng Wu, Lijing Shao, Rongfeng Shen, Xiaofeng Wang, Joel Bregman, Rosanne Di Stefano, Qingzhong Liu, Zhanwen Han, Tianmeng Zhang, Huijuan Wang, Juanjuan Ren, Junbo Zhang, Jujia Zhang, Xiaoli Wang, Antonio Cabrera-Lavers, Romano Corradi, Rafael Rebolo, Yongheng Zhao, Gang Zhao, Yaoquan Chu, Xiangqun CuiComments: Published in Nature on Nov 28, 2019Subjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)
All stellar mass black holes have hitherto been identified by X-rays emitted by gas that is accreting onto the black hole from a companion star. These systems are all binaries with black holes below 30 M$_{\odot}$$^{1-4}$. Theory predicts, however, that X-ray emitting systems form a minority of the total population of star-black hole binaries$^{5,6}$. When the black hole is not accreting gas, it can be found through radial velocity measurements of the motion of the companion star. Here we report radial velocity measurements of a Galactic star, LB-1, which is a B-type star, taken over two years. We find that the motion of the B-star and an accompanying H$\alpha$ emission line require the presence of a dark companion with a mass of $68^{+11}_{-13}$ M$_{\odot}$, which can only be a black hole. The long orbital period of 78.9 days shows that this is a wide binary system. The gravitational wave experiments have detected similarly massive black holes$^{7,8}$, but forming such massive ones in a high-metallicity environment would be extremely challenging to current stellar evolution theories$^{9-11}$.
- [34] arXiv:1911.12024 [pdf, other]
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Title: Probing the emission states of PSR J1107-5907Authors: Jingbo Wang, George Hobbs, Matthew Kerr, Ryan Shannon, Shi Dai, Vikram Ravi, Andrew Cameron, Jane F. Kaczmarek, Robert Hollow, Di Li, Lei Zhang, Chenchen Miao, Mao Yuan, Shen Wang, Songbo Zhang, Heng Xu, Renxin XuComments: 7 pages, 6 figures, accepted by ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)
The emission from PSR J1107-5907 is erratic. Sometimes the radio pulse is undetectable, at other times the pulsed emission is weak, and for short durations the emission can be very bright. In order to improve our understanding of these state changes, we have identified archival data sets from the Parkes radio telescope in which the bright emission is present, and find that the emission never switches from the bright state to the weak state, but instead always transitions to the off state. Previous work had suggested the identification of the off state as an extreme manifestation of the weak state. However, the connection between the off and bright emission reported here suggests that the emission can be interpreted as undergoing only two emission states: a bursting state consisting of both bright pulses and nulls as well as the weak-emission state.
- [35] arXiv:1911.12025 [pdf, ps, other]
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Title: A peculiar cyclotron line near 16 keV detected in the 2015 outburst of 4U 0115+63?Authors: Bai-Sheng Liu, Lian Tao, Shuang-Nan Zhang, Xiang-Dong Li, Ming-Yu Ge, Jin-Lu Qu, Li-Ming Song, Long Ji, Shu Zhang, Andrea Santangelo, Ling-Jun WangComments: 22 pages, 7 figures, submittedSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
In 2015 October, the Be/X-ray binary 4U 0115+63 underwent a type II outburst, reaching an X-ray luminosity of about 10^38 erg/s. During the outburst, Nuclear Spectroscopic Telescope Array ({\it NuSTAR}) performed two Target of Opportunity observations. Using the broad-band spectra from {\it NuSTAR} (3$-$79 keV), we have detected multiple cyclotron lines of the source, i.e., $\sim$ 12, 16, 22 and 33/35 keV. Obviously, the 16 keV line is not a harmonic component of the 12 keV line. As described by the phase-dependent equivalent widths of these cyclotron lines, the 16 keV and 12 keV lines are two distinct fundamental lines. We propose a model, in which the two line sets are formed in different regions of the same magnetic pole. That is, the former is produced in the outer-region of the column base, and the latter is at a height of $\sim$ 1 km inside the column if the magnetic dipole field is assumed. Thus the magnetic field, deduced from the cyclotron line near 16 keV, is $\sim$ {1.4*10^12} G.
- [36] arXiv:1911.12056 [pdf, ps, other]
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Title: Angular Redshift Fluctuations: a New Cosmological ObservableAuthors: Carlos Hernandez-Monteagudo (1), Jonas Chaves-Montero (2), Raul E. Angulo (3) ((1) CEFCA, (2) ANL, (3) DIPC)Comments: 5 pages, 3 figures, to be (re-)submitted to PRL shortly, companion paper of Chaves-Montero et al., arXiv:1911.10690Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We propose the use of angular fluctuations in the galaxy redshift field as a new way to extract cosmological information in the Universe. This new probe consists on the statistics of sky maps built by projecting redshifts under a Gaussian window of mean $z_{\rm obs}$ and width $\sigma_z$; $z(\hat{\mbox{n}}) = \bar{z}+\sum_{j\in \hat{\mbox{n}}} W_j (z_j-\bar{z}) / \langle \sum_i W_i \rangle= \bar{z} + \delta z (\hat{\mbox{n}})$, with $z_j$ and $W_j$ the redshift and the Gaussian weight, respectively, for the $j$-th galaxy falling on the pixel along sky direction $\hat{\mbox{n}}$, $\bar{z}=\sum_i W_i z_i / \sum_i W_i$ is the average redshift under the Gaussian shell, and the $\langle ... \rangle$ brackets denote an angular average over the entire footprint. We compute the angular power spectrum of the $\delta z (\hat{\mbox{n}})$ field in both numerical simulations and in linear perturbation theory. From these we find that the $\delta z (\hat{\mbox{n}})$ field: {\it (i)} is sensitive to the underlying density and peculiar velocity fields; {\it (ii)} is highly correlated, at the $\gtrsim 60\,\%$ level, to the line-of-sight projected peculiar velocity field; {\it (iii)} for narrow windows $(\sigma_z < 0.03$), it is almost completely uncorrelated to the projected galaxy angular density field under the same redshift window; and {\it (iv)} it is largely unaffected by multiplicative and additive systematic errors on the observed number of galaxies that are redshift-independent over $\sim\sigma_z$. We conclude that $\delta z (\hat{\mbox{n}})$ is a simple and robust tomographic measure of the cosmic density and velocity fields, complementary to angular clustering, that will contribute to a more complete exploitation of current and upcoming galaxy redshift surveys.
- [37] arXiv:1911.12068 [pdf, ps, other]
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Title: Tidal disruption of planetary bodies by white dwarfs I: A hybrid SPH-analytical approachSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
We introduce a new hybrid method to perform high-resolution tidal disruption simulations, at arbitrary orbits. An SPH code is used to simulate tidal disruptions only in the immediate spatial domain of the star, namely, where the tidal forces dominate over gravity, and then during the fragmentation phase in which the emerging tidal stream may collapse under its own gravity to form fragments. Following each hydrodynamical simulation, an analytical treatment is then applied to instantaneously transfer each fragment back to the tidal sphere for its subsequent disruption, in an iterative process. We validate the hybrid model by comparing it to both an analytical impulse approximation model of single tidal disruptions, as well as full-scale SPH simulations spanning the entire disc formation. The hybrid simulations are essentially indistinguishable from the full-scale SPH simulations, while computationally outperforming their counterparts by orders of magnitude. Thereby our new hybrid approach uniquely enables us to follow the long-term formation and continuous tidal disruption of the planet/planetesimal debris, without the resolution and orbital configuration limitation of previous studies. In addition, we describe a variety of future directions and applications for our hybrid model.
- [38] arXiv:1911.12076 [pdf, other]
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Title: Test the effects of $H_0$ on $fσ_8$ tension with Gaussian Process methodComments: 15 pages, 8 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Using the $f\sigma_8(z)$ redshift space distortion (RSD) data, the $\sigma_8^0-\Omega_m^0$ tension is studied utilizing a parameterization of growth rate $f(z) = \Omega_m(z)^\gamma$. Here, $f(z)$ is derived from the expansion history $H(z)$ which is reconstructed from the observational Hubble data applying the Gaussian Process method. It is found that different priors of $H_0$ have a great influence on the evolution curve of $H(z)$ and the constraint of $\sigma_8^0-\Omega_m^0$. When using a larger $H_0$ prior, the low redshifts $H(z)$ deviate significantly from that of the $\Lambda$CDM model, which indicates that a dark energy model different from the cosmological constant can help to relax the $H_0$ tension problem. The tension between our best-fit values of $\sigma_8^0-\Omega_m^0$ and that of the \textit{Planck} 2018 $\Lambda$CDM (PLA) will disappear (less than $1\sigma$) when taking a prior for $H_0$ obtained from PLA. Moreover, the tension exceeds $2\sigma$ level when applying the prior $H_0 = 73.52 \pm 1.62$ resulted from the Hubble Space Telescope photometry.
- [39] arXiv:1911.12077 [html]
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Title: Cherenkov Telescope Array (CTA) Contributions to the 36th International Cosmic Ray Conference (ICRC2019)Authors: The CTA ConsortiumSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
List of contributions from the Cherenkov Telescope Array (CTA) Consortium presented at the 36th International Cosmic Ray Conference, July 24 - August 1 2019, Madison, WI, EUA.
- [40] arXiv:1911.12083 [pdf, other]
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Title: The Mystery of Photometric Twins DES17X1boj and DES16E2bjyAuthors: M. Pursiainen, C. Gutierrez, P. Wiseman, M. Childress, M. Smith, C. Frohmaier, C. Angus, N. Castro Segura, L. Kelsey, M. Sullivan, L. Galbany, P. Nugent, B. A. Bassett, D. Brout, D. Carollo, C. B. D'Andrea, T. M. Davis, M. Grayling, S. R. Hinton, C. Inserra, R. Kessler, C. Lidman, E. Macaulay, M. March, A. Moöller, T. Müller, D. Scolnic, E. Swann, B. P. Thomas, M. Vincenzi, T. M. C. Abbott, S. Allam, J. Annis, S. Avila, E. Bertin, D. Brooks, E. Buckley-Geer, D. L. Burke, A. Carnero Rosell, M. Carrasco Kind, L. N. da Costa, J. De Vicente, S. Desai, H. T. Diehl, P. Doel, T. F. Eifler, S. Everett, B. Flaugher, J. Frieman, J. García-Bellido, E. Gaztanaga, D. W. Gerdes, D. Gruen, R. A. Gruendl, J. Gschwend, G. Gutierrez, D. L. Hollowood, K. Honscheid, D. J. James, A. G. Kim, et al. (20 additional authors not shown)Comments: Submitted to MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We present an analysis of DES17X1boj and DES16E2bjy, two peculiar transients discovered by the Dark Energy Survey (DES). They exhibit nearly identical double-peaked light curves which reach very different maximum luminosities (M$_\mathrm{r}$ = -15.4 and M$_\mathrm{r}$ = -17.9, respectively). The light curve evolution of these events is highly atypical and has not been reported before. The transients are found in different host environments: DES17X1boj was found near the nucleus of a spiral galaxy, while DES16E2bjy is located in the outskirts of a passive red galaxy. Early photometric data is well fitted with a blackbody and the resulting moderate photospheric expansion velocities (1800 km/s for DES17X1boj and 4800 km/s for DES16E2bjy) suggest an explosive or eruptive origin. Additionally, a feature identified as high-velocity CaII absorption (v $\approx$ 9400km/s) in the near-peak spectrum of DES17X1boj may imply that it is a supernova. While similar light curve evolution suggests a similar physical origin for these two transients, we are not able to identify or characterise the progenitors.
- [41] arXiv:1911.12084 [pdf, other]
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Title: On (non-)dynamical dark energyComments: 5 pages, 2 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
The current Universe is composed by a mixture of relativistic species, baryonic matter, dark matter and dark energy which evolve in a non-trivial way at perturbative level. A successful description of the cosmological dynamics should include non-standard features beyond the simplistic approach idealized by the standard cosmology in which cosmic components do not interact, are adiabatic and dissipationless. We promote a full perturbative analysis of linear scalar perturbations of a cosmological model containing baryons, dark matter and a scalar field allowing for the presence of relative entropic perturbations between the three fluids. We show that tiny departures from a constant scalar field equation of state $w_{S}=-1$ damage structure formation in a non-acceptable manner. Hence, by strongly constraining $w_S$ our results provide compelling evidence in favor of the standard cosmological model and rule out a large class of dynamical dark energy models.
- [42] arXiv:1911.12087 [pdf, ps, other]
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Title: Investigation of the Gamma-ray Spectrum of CTA 102 During the Exceptional Flaring State in 2016-2017Authors: N. SahakyanComments: Accepted for publication in Astronomy & AstrophysicsSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
The flat spectrum radio quasar CTA 102 entered an extended period of activity from 2016 to 2017 during which several strong $\gamma$-ray flares were observed. Using Fermi large area telescope data a detailed investigation of \gray spectra of CTA 102 during the flaring period is performed. In several periods the \gray spectrum is not consistent with a simple power-law, having a hard photon index with an index of $\sim(1.8-2.0)$ that shows a spectral cutoff around an observed photon energy of $\sim(9-16)$ GeV. The internal $\gamma$-ray absorption via photon-photon pair production on the broad-line-region-reflected photons cannot account for the observed cut-off/break even if the emitting region is very close to the central source. This cut-off/break is likely due to a similar intrinsic break in the energy distribution of emitting particles. The origin of the spectral break is investigated through the multiwavelength modeling of the spectral energy distribution, considering a different location for the emitting region. The observed X-ray and $\gamma$-ray data is modeled as inverse Compton scattering of synchrotron and/or external photons on the electron population that produce the radio-to-optical emission which allowed to constrain the power-law index and cut-off energy in the electron energy distribution. The obtained results are discussed in the context of a diffusive acceleration of electrons in the CTA 102 jet.
- [43] arXiv:1911.12094 [pdf, other]
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Title: Viscous Evolution of Magnetized Clumps: a Source for X-ray Flares in Gamma-ray BurstsComments: Accepted for publication in ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
X-ray flares can be accounted for a hint to the late time activity of Gamma-ray bursts (GRBs) central engines. Such a long term activity has been described through some models, one of which is the viscous evolution of the outer disc fragments that proposed by Perna et al. (2006), and developed quantitatively by Dall Osso et al. (2017). Here, we reconstruct Dall Osso et al. (2017) framework through taking both small and large scale effects of magnetic field into account. To consider the magnetic barrier as a possible mechanism that might govern the accretion process of each magnetized clump, we make a simple pattern in boundary condition through which this mechanism might happen. Regarding various model parameters, we probe for their influence and proceed some key analogies between our model predictions and previous phenomenological estimates, for two different choices of boundary conditions (with and without a magnetic barrier). Our model is remarkably capable of matching flare bolometric and X-ray light-curves, as well as reproducing their statistical properties, such as the ratios between rise and decay time, width parameter and peak time, and the power-law correlation between peak luminosity and peak time. Combining our results with the conclusions of previous studies, we are led to interpret magnetic barrier as a less probable mechanism that might control the evolution of these clumps, especially the later created (or viscously evolved) ones.
- [44] arXiv:1911.12100 [pdf, other]
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Title: Mass motion in a prominence bubble revealing a kinked flux rope configurationComments: To appear in Journal: Frontiers in Physics - Stellar and Solar Physics; Research Topic: Magnetic Flux Ropes: From the Sun to the Earth and BeyondSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Plasma Physics (physics.plasm-ph)
Prominence bubbles are cavities rising into quiescent prominences from below. The bubble-prominence interface is often the active location for the formation of plumes, which flow turbulently into quiescent prominences. Not only the origin of prominence bubbles is poorly understood, but most of their physical characteristics are still largely unknown. Here, we investigate the dynamical properties of a bubble, which is observed since its early emergence beneath the spine of a quiescent prominence on 20 October 2017 in the H$\alpha$ line-center and in $\pm$0.4 angstrom line-wing wavelengths by the 1-m New Vacuum Solar Telescope. We report the prominence bubble to be exhibiting a disparate morphology in the H$\alpha$ line-center compared to its line-wings' images, indicating a complex pattern of mass motion along the line-of-sight. Combining Doppler maps with flow maps in the plane of sky derived from a Nonlinear Affine Velocity Estimator, we obtained a comprehensive picture of mass motions revealing a counter-clockwise rotation inside the bubble; with blue-shifted material flowing upward and red-shifted material flowing downward. This sequence of mass motions is interpreted to be either outlining a kinked flux rope configuration of the prominence bubble or providing observational evidence of the internal kink instability in the prominence plasma.
- [45] arXiv:1911.12114 [pdf, other]
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Title: Exoplanet Vision 2050Authors: René Heller (1), László Kiss ((1) Max Planck Institute for Solar System Research, Göttingen (GER), (2) Konkoly Observatory, Budapest (HUN))Comments: Based on an invited talk (RH) at the "Exoplanet Vision 2050" workshop, Konkoly Observatory, 21. Nov. 2019; 2 col. figuresSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Is there any hope for us to draw a plausible picture of the future of exoplanet research? Here we extrapolate from the first 25 years of exoplanet discovery into the year 2050. If the power law for the cumulative exoplanet count continues, then almost 100,000,000 exoplanets would be known by 2050. Although this number sounds ridiculously large, we find that the power law could plausibly continue until at least as far as 2030, when Gaia will have discovered tens of thousands of exoplanets. After an early era of radial velocity detection, we are now in the transit era, which might be followed by an astrometry era introduced by the Gaia mission. And then? Maybe more is not better. A small and informal survey among astronomers at the "Exoplanet Vision 2050" workshop in Budapest suggests that astrobiological topics might influence the future of exoplanet research.
- [46] arXiv:1911.12123 [pdf, other]
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Title: Gravitational Lens System PS J0147+4630 (Andromeda's Parachute): Main Lensing Galaxy and Optical Variability of the Quasar ImagesComments: 12 pages, 8 figures, 2 tables. Accepted for publication in ApJSubjects: Astrophysics of Galaxies (astro-ph.GA)
Because follow-up observations of quadruple gravitational lens systems are of extraordinary importance for astrophysics and cosmology, we present single-epoch optical spectra and $r$--band light curves of PS J0147+4630. This recently discovered system mainly consists of four images ABCD of a background quasar around a foreground galaxy G that acts as a gravitational lens. First, we use long--slit spectroscopic data in the Gemini Observatory Archive and a multi-component fitting to accurately resolve the spectra of A, D, and G. The spectral profile of G resembles that of an early-type galaxy at a redshift of 0.678 $\pm$ 0.001, which is about 20\% higher than the previous estimate. Additionally, the stellar velocity dispersion is measured to $\sim$5\% precision. Second, our early $r$-band monitoring with the Liverpool Telescope leads to accurate light curves of the four quasar images. Adopting time delays predicted by the lens model, the new lens redshift, and a standard cosmology, we report the detection of microlensing variations in C and D as large as $\sim$0.1 mag on timescales of a few hundred days. We also estimate an actual delay between A and B of a few days (B is leading), which demonstrates the big potential of optical monitoring campaigns of PS J0147+4630.
- [47] arXiv:1911.12176 [pdf, other]
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Title: AGN types and unification modelComments: Invited talk at IAU Symp 356 "Nuclear Activity in Galaxies Across Cosmic Time", ed. M. Povic et alSubjects: Astrophysics of Galaxies (astro-ph.GA)
The motivation of the "unified model" is to explain the main properties of the large zoo of active galactic nuclei with a single physical object. The discovery of broad permitted lines in the polarized spectrum of type 2 Seyfert galaxies in the mid 80's led to the idea of an obscuring torus, whose orientation with respect to our line of sight was the reason of the different optical spectra. However, after many years of observations with different techniques, including IR and mm interferometry, the resulting properties of the observed dust structures differ from the torus model that would be needed to explain the type 1 vs type 2 dichotomy. Moreover, in the last years, multi-frequency monitoring of active galactic nuclei has shown an increasing number of transitions from one type to the other one, which cannot be explained in terms of the simple orientation of the dusty structure surrounding the active galactic nucleus (AGN). The interrelations between the AGN and the host galaxy, as also shown in the Magorrian relation, suggest that the evolution of the host galaxy may also have an important role in the observed manifestation of the nuclei. As an example, the observed delay between the maximum star formation activity and the onset of the AGN activity, and the higher occurrence of type 2 nuclei in star forming galaxies, have suggested the possible evolutionary path from, e.g., HII $\rightarrow$ AGN2 $\rightarrow$ AGN1. In the next years the models of unification need to also consider this observational framework and not only simple orientation effects.
- [48] arXiv:1911.12181 [pdf, other]
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Title: Unveiling the physical processes that regulate Galaxy Evolution with SPICA observationsComments: Contributed talk at the IAU Symp 356 "Nuclear Activity in Galaxies Across Cosmic Time", ed. M. Povic et alSubjects: Astrophysics of Galaxies (astro-ph.GA)
To study the dust obscured phase of the galaxy evolution during the peak of the Star Formation Rate (SFR) and the Black Hole Accretion Rate (BHAR) density functions ($z = 1 - 4$), rest frame mid-to-far infrared (IR) spectroscopy is needed. At these frequencies, dust extinction is at its minimum and a variety of atomic and molecular transitions, tracing most astrophysical domains, occur. The future IR space telescope mission, SPICA, fully redesigned with its $2.5\, \rm{m}$ mirror cooled down to $T < 8\, \rm{K}$, will be able to perform such observations. With SPICA, we will: 1) obtain a direct spectroscopic measurement of the SFR and of the BHAR histories, 2) measure the evolution of metals and dust to establish the matter cycle in galaxies, 3) uncover the feedback and feeding mechanisms in large samples of distant galaxies, either AGN- or starburst-dominated, reaching lookback times of nearly 12 Gyr. SPICA large-area deep surveys will provide low-resolution, mid-IR spectra and continuum fluxes for unbiased samples of tens of thousands of galaxies, and even the potential to uncover the youngest, most luminous galaxies in the first few hundred million years. In this talk a brief review of the scientific preparatory work that has been done in extragalactic astronomy by the SPICA Collaboration will be given.
- [49] arXiv:1911.12184 [pdf, ps, other]
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Title: Tidal disruption of planetary bodies by white dwarfs II: Debris disk structure and ejected interstellar asteroidsSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
We make use of a new hybrid method to simulate the long-term, multiple-orbit disc formation through tidal disruptions of rocky bodies by white dwarfs, at high-resolution and realistic semi-major axis. We perform the largest suite of simulations for dwarf and terrestrial planets, spanning four orders of magnitude in mass, various pericentre distances and semi-major axes between 3 AU and 150 AU. This large phase space of tidal disruption conditions has not been accessible through the use of previous codes. We analyse the statistical and structural properties of the emerging debris discs, as well as the ejected unbound debris contributing to the population of interstellar asteroids. Unlike previous tidal disruption studies of small asteroids which form ring-like structures on the original orbit, we find that the tidal disruption of larger bodies usually forms dispersed structures of interlaced elliptic eccentric annuli on tighter orbits. We characterize the (typically power-law) size-distribution of the ejected interstellar bodies as well as their composition, rotation velocities and ejection velocities. We find them to be sensitive to the depth (impact parameter) of the tidal disruption. Finally, we briefly discuss possible implications of our results in explaining the peculiar variability of Tabby's star, the origin of the transit events of ZTF J0139 and the formation of the intact core of SDSS J122859.93.
- [50] arXiv:1911.12228 [pdf, other]
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Title: Interstellar Asteroid Rotation with the Mechanical Torque Produced by Interstellar MediumAuthors: Wen Han ZhouComments: 7 pages, 9 figuresSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
The first interstellar object 'Oumuamua is discovered in 2017. When it travels in interstellar space, it keeps colliding with interstellar medium (ISM). Given a sufficiently long interaction time, its rotation state may change significantly because of the angular momentum transfer with interstellar medium. This research first obtains the torque curve and rotation evolution of the asteroid that collides with interstellar medium by numerical simulation. Several kinds of shapes are generated by method of Gaussian random sphere: spheroidal, oblate, prolate shapes. A pseudo 'Oumuamua is generated with the dimension ratio 7:1 :1. The results show that asteroids will incline ultimately to a stable orientation such that its axis of maximum moment of inertia is perpendicular to its velocity vector. Oblate shapes are easier to incline than spheroidal and prolate shapes. Pseudo 'Oumuamua is tested under different initial conditions. When rubble piles rotate so fast that disruption is found to be about 5.05 Gyrs and major axis is in alignment to around 93.5 degree from its velocity vector at disruption. Considering the significant effect of interstellar medium, the excitedly tumbling motion of 'Oumuamua may result from its collision with interstellar medium. Rotation of asteroids in Oort Cloud may be dominated by ISM collision effect since YORP effect is quite weak at distance of 50000AU from the Sun.
- [51] arXiv:1911.12243 [pdf, ps, other]
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Title: IRIS Mg II Observations and Non-LTE Modeling of Off-limb Spicules in a Solar Polar Coronal HoleAuthors: Akiko Tei, Stanislav Gunar, Petr Heinzel, Takenori J. Okamoto, Jiri Stepan, Sonja Jejcic, Kazunari ShibataComments: 19 pages, 11 figures, accepted in the Astrophysical JournalSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
We investigated the off-limb spicules observed in the Mg II h and k lines by IRIS in a solar polar coronal hole. We analyzed the large dataset of obtained spectra to extract quantitative information about the line intensities, shifts, and widths. The observed Mg II line profiles are broad and double-peaked at lower altitudes, broad but flat-topped at middle altitudes, and narrow and single-peaked with the largest Doppler shifts at higher altitudes. We use 1D non-LTE vertical slab models (i.e. models which consider departures from Local Thermodynamic Equilibrium) in single-slab and multi-slab configurations to interpret the observations and to investigate how a superposition of spicules along the line of sight (LOS) affects the synthetic Mg II line profiles. The used multi-slab models are either static, i.e. without any LOS velocities, or assume randomly assigned LOS velocities of individual slabs, representing the spicule dynamics. We conducted such single-slab and multi-slab modeling for a broad set of model input parameters and showed the dependence of the Mg II line profiles on these parameters. We demonstrated that the observed line widths of the h and k line profiles are strongly affected by the presence of multiple spicules along the LOS. We later showed that the profiles obtained at higher altitudes can be reproduced by single-slab models representing individual spicules. We found that the multi-slab model with a random distribution of the LOS velocities ranging from -25 to 25 km s$^{-1}$ can well reproduce the width and the shape of Mg II profiles observed at middle altitudes.
- [52] arXiv:1911.12297 [pdf, ps, other]
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Title: The jet/counter-jet symmetry of the HH 212 outflowAuthors: A. Noriega-Crespo (1), A.C. Raga (2), V. Lora (3), J.C. Rodriguez-Ramirez (4), (1) STScI, (2)ICN, UNAM, (3) IRAT, UNAM, (4)IAG, USPComments: 11 pages, 6 figures, accepted for publication in RevMexAstrAstrfSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE)
We present Spitzer (IRAC) images observations and a VLT 2.1micron image of the HH 212 outflow. We find that this outflow has a strong symmetry, with jet/counterjet knot pairs with Delta x less than 1 arcsec position offsets. We deduce that the jet/counterjet knots are ejected with time differences Delta tau_0 approx. 6 yr and velocity differences Delta v_0~ 2 km/s. We also analyze the deviations of the knot positions perpendicular to the outflow axis, and interpret them in terms of a binary orbital motion of the outflow source. Through this model, we deduce a ~0.7M_solar mass for the outflow source, and a separation of ~80 AU between the components of the binary (assuming equal masses for the two components). Finally, using the IRAC data and the VLT 2.1micron image we have measured the proper motion velocities, obtaining values from 50 to 170km/s.
- [53] arXiv:1911.12314 [pdf, other]
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Title: The AGILE Data Center and its LegacyAuthors: Carlotta Pittori (on behalf of the AGILE-SSDC Team)Comments: This is a pre-print of an article published in Rendiconti Lincei, Scienze Fisiche e Naturali, part of the topical collections: "A Decade of AGILE: Results, Challenges and Prospects of Gamma-Ray Astrophysics". The final authenticated version is available online at: this https URLJournal-ref: Rendiconti Lincei, Scienze Fisiche e Naturali, 30(1), 217-223 (2019)Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
We present an overview of the main AGILE Data Center activities and architecture. AGILE is a space mission of the Italian Space Agency (ASI) in joint collaboration with INAF, INFN, CIFS, and with the participation of several Italian space industry companies. The AGILE satellite was launched on April 23, 2007, and is devoted to the observation of the gamma-ray Universe in the 30 MeV -- 50 GeV energy range, with simultaneous X-ray imaging capability in the 18-60 keV band. The AGILE Data Center, part of the ASI multi-mission Space Science Data Center (SSDC, previously known as ASDC) is in charge of all the scientific operations: data management, archiving, distribution of AGILE data and scientific software, and user support. Thanks to its sky monitoring capability and fast ground segment alert system, AGILE is substantially improving our knowledge of the gamma-ray sky, and provides a crucial contribution to multimessenger follow-up of gravitational waves and neutrinos
- [54] arXiv:1911.12325 [pdf, other]
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Title: HD/H$_2$ ratio in the diffuse interstellar mediumComments: 5 pages, 3 figures, accepted for publication in MNRAS lettersSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We present a semi-analytical description of the relative HD/H2 abundance in the diffuse interstellar medium. We found three asymptotics of the relative HD/H$_2$ abundance for different parts of the medium and their dependence on the physical parameters, namely, number density, intensity of the ultraviolet field, cosmic-ray ionization rate and metallicity. Our calculations are in a good agreement with the full network calculations using Meudon PDR code. We found that in the case of low metallicity and/or higher cosmic ray ionization rate, HD formation rate is significantly enhanced, HD/H2 ratio increases, and the DI/HD transition occurs at a lower penetration depth of UV radiation than the HI/H$_2$ transition. This can explain the observed difference in the HD/H$_2$ abundance between the local and high-redshift measurements.
- [55] arXiv:1911.12326 [pdf, ps, other]
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Title: Analysis of first overtone bands of isotopologues of CO and SiO in stellar spectraAuthors: Ya. V. Pavlenko (MAO, UA, UH, UK), Sergei N. Yurchenko (UCL, UK), Jonathan Tennyson (UCL, UK)Comments: 9 pages, 6 figures, accepted by A&ASubjects: Solar and Stellar Astrophysics (astro-ph.SR)
The first overtone ($\Delta v$ = 2) bands of the monosubstituted isotopologues of CO at 2.3 $\mu$m in the spectrum of Arcturus (K2 III), and of the monosubstituted isotopologues of SiO at 4 $\mu$m in the spectrum of the red giant HD196610 (M6 III) are modelled.
To investigate problems involving the computation of the first overtone bands of isotopologues of CO and SiO in spectra of late-type stars and to determine isotopic abundances.
We use fits of theoretical synthetic spectra to the observed stellar molecular bands of CO and SiO to determine abundances of isotopes of C, O and Si.
Fits of synthetic spectra of the \CO first overtone bands at 2.3 $\mu$m computed with three available line lists (Goorvitch, HITEMP2010 and Li et al.) to the observed spectrum of Arcturus provide the same carbon abundance [C]=$-0.6$ and isotopic ratio of carbon $^{12}$C/$^{13}$C=10 $\pm$ 2. However, the quality of fits to the observed spectrum differ for three line lists used. Furthermore, the derived oxygen isotopic ratio $^{16}$O/$^{18}$O = 2000 $\pm$ 500 is larger than that known in the solar system where $^{16}$O/$^{18}$O = 500. The silicon isotopic ratio in the atmosphere of the red giant HD196610 is revised. Using the ExoMol SiO line list with appropriate statistical weights for the SiO isotopologues the `non-solar' ratio $^{28}$Si:$^{29}$Si:$^{30}$Si = 0.86$\pm$0.03:0.12$\pm$0.02:0.02$\pm$0.01 is obtained.
We found that a) the computed isotopic carbon and silicon ratios determined by the fits to the observed spectrum depend on the adopted abundance of C and Si, respectively; b) Correct treatment of the nuclear spin degeneracies parameter is of crucial importance for the use of nowadays HITRAN/ExoMol line lists in the astrophysical computations. - [56] arXiv:1911.12337 [pdf, other]
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Title: Multilevel and hierarchical Bayesian modeling of cosmic populationsComments: 33 pages, 5 figuresSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Applications (stat.AP)
Demographic studies of cosmic populations must contend with measurement errors and selection effects. We survey some of the key ideas astronomers have developed to deal with these complications, in the context of galaxy surveys and the literature on corrections for Malmquist and Eddington bias. From the perspective of modern statistics, such corrections arise naturally in the context of multilevel models, particularly in Bayesian treatments of such models: hierarchical Bayesian models. We survey some key lessons from hierarchical Bayesian modeling, including shrinkage estimation, which is closely related to traditional corrections devised by astronomers. We describe a framework for hierarchical Bayesian modeling of cosmic populations, tailored to features of astronomical surveys that are not typical of surveys in other disciplines. This thinned latent marked point process framework accounts for the tie between selection (detection) and measurement in astronomical surveys, treating selection and measurement error effects in a self-consistent manner.
- [57] arXiv:1911.12348 [pdf, ps, other]
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Title: Variability in Proto-Planetary Nebulae: VI. Multi-Telescope Light Curves Studies of Several Medium-Bright (V=13-15), Carbon-Rich ObjectsAuthors: Bruce J. Hrivnak, Gary Henson, Todd C. Hillwig, Wenxian Lu, Brian W. Murphy, Ronald H. KaitchuckComments: 25 pages, 14 figures, 1 electronic table, accepted for publication in the Astronomical JournalSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
We present ten years of new photometric monitoring of the light variability of five evolved stars with strong mid-infrared emission from surrounding dust. Three are known carbon-rich proto-planetary nebulae (PPNe) with F$-$G spectral types; the nature of the other two was previously unknown. For the three PPNe, we determine or refine the pulsation periods of IRAS 04296+3429 (71 days), 06530$-$0213 (80 days), and 23304+6147 (84 days). A secondary period was found for each, with a period ratio P$_2$/P$_1$ of 0.9. The light variations are small, 0.1-0.2 mag. These are similar to values found in other PPNe. The other two are found to be giant stars. IRAS 09296+1159 pulsates with a period of only 47 days but reaches pulsational light variations of 0.5 mag. Supplemental spectroscopy reveals the spectrum of a CH carbon star. IRAS 08359$-$1644 is a G1III star that does not display pulsational variability; rather, it shows non-periodic decreases of brightness of up to 0.5 mag over this ten-year interval. These drops in brightness are reminiscent of the light curves of R Corona Borealis variables, but with much smaller decreases in brightness, and are likely due to transient dust obscuration. Its SED is very similar to that of the unusual oxygen-rich giant star HDE 233517, which possesses mid-infrared hydrocarbon emission features. These two non-PPNe turn out to members of the rare group of giant stars with large mid-infrared excesses due to dust, objects which presumably have interesting evolutionary histories.
- [58] arXiv:1911.12357 [pdf, other]
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Title: The Formation of a 70 Msun Black Hole at High MetallicityAuthors: K.Belczynski, R.Hirschi, E.A.Kaiser, Jifeng Liu, J.Casares, Youjun Lu, R.O'Shaughnessy, A.Heger, S.JusthamComments: ApJ, submittedSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
A 70 Msun black hole was discovered in Milky Way disk in a long period (P=78.9d) and almost circular ($e=0.03$) detached binary system (LB-1) with an 8 Msun B star companion. The metallicity of the B star is near solar (Z=0.02). Current consensus on the formation of black holes from high metallicity stars limits the black hole mass to be below 20 Msun due to strong mass loss in stellar winds. Using the Hurley et al. (2000) analytic evolutionary formulae, we show that the formation of a 70 Msun black hole in high metallicity environment is possible if stellar wind mass loss rates, that are typically adopted in evolutionary calculations, are reduced by factor of 0.2. Recent observational evidence and theoretical calculations indicate that Vink et al. (2001) wind mass loss estimates may need to be reduced by factors as low as 0.5-0.1. We also computed detailed stellar evolution models and we confirm such a scenario. A non-rotating 85 Msun star model at Z=0.014 with decreased winds ends up as a 71 Msun star prior core-collapse with a 32 Msun helium core and a 28 Msun CO core. Such star avoids pair-instability pulsation supernova mass loss that severely limits black hole mass and may form a 70 Msun black hole in the direct collapse. Stars that can form 70 Msun black holes at high Z expand to significant size with radius of >600 Rsun (thanks to large H-rich envelope), however, exceeding the size of LB-1 orbit (semi-major axis a<350 Rsun. Current standard stellar evolution models appear to be consistent with the formation of black holes upto 70 Msun at high metallicity, but unable to explain how a binary star system like LB-1 could have formed without invoking some exotic scenarios.
Cross-lists for Thu, 28 Nov 19
- [59] arXiv:1911.11779 (cross-list from gr-qc) [pdf, other]
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Title: Enabling real-time multi-messenger astrophysics discoveries with deep learningAuthors: E. A. Huerta, Gabrielle Allen, Igor Andreoni, Javier M. Antelis, Etienne Bachelet, Bruce Berriman, Federica Bianco, Rahul Biswas, Matias Carrasco, Kyle Chard, Minsik Cho, Philip S. Cowperthwaite, Zachariah B. Etienne, Maya Fishbach, Francisco Förster, Daniel George, Tom Gibbs, Matthew Graham, William Gropp, Robert Gruendl, Anushri Gupta, Roland Haas, Sarah Habib, Elise Jennings, Margaret W. G. Johnson, Erik Katsavounidis, Daniel S. Katz, Asad Khan, Volodymyr Kindratenko, William T. C. Kramer, Xin Liu, Ashish Mahabal, Zsuzsa Marka, Kenton McHenry, Jonah Miller, Claudia Moreno, Mark Neubauer, Steve Oberlin, Alexander R. Olivas, Donald Petravick, Adam Rebei, Shawn Rosofsky, Milton Ruiz, Aaron Saxton, Bernard F. Schutz, Alex Schwing, Ed Seidel, Stuart L. Shapiro, Hongyu Shen, Yue Shen, Leo Singer, et al. (9 additional authors not shown)Comments: Invited Expert Recommendation for Nature Reviews Physics. The art work produced by E. A. Huerta and Shawn Rosofsky for this article was used by Carl Conway to design the cover of the October 2019 issue of Nature Reviews PhysicsJournal-ref: Nature Reviews Physics volume 1, pages 600-608 (2019)Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM); Machine Learning (cs.LG)
Multi-messenger astrophysics is a fast-growing, interdisciplinary field that combines data, which vary in volume and speed of data processing, from many different instruments that probe the Universe using different cosmic messengers: electromagnetic waves, cosmic rays, gravitational waves and neutrinos. In this Expert Recommendation, we review the key challenges of real-time observations of gravitational wave sources and their electromagnetic and astroparticle counterparts, and make a number of recommendations to maximize their potential for scientific discovery. These recommendations refer to the design of scalable and computationally efficient machine learning algorithms; the cyber-infrastructure to numerically simulate astrophysical sources, and to process and interpret multi-messenger astrophysics data; the management of gravitational wave detections to trigger real-time alerts for electromagnetic and astroparticle follow-ups; a vision to harness future developments of machine learning and cyber-infrastructure resources to cope with the big-data requirements; and the need to build a community of experts to realize the goals of multi-messenger astrophysics.
- [60] arXiv:1911.11823 (cross-list from gr-qc) [pdf, ps, other]
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Title: Ringing of the regular black-hole/wormhole transitionComments: 6 pages, 3 figures, revtexSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)
Recently a simple one-parameter generalization of the Schwarzschild spacetime was suggested by A. Simpson and M. Visser [JCAP 1902, 042 (2019)] as a toy model describing the regular black hole and traversable wormhole states separated by the border (one-way wormhole) state, depending on the value of the new parameter. Here we will study quasinormal modes of all three states and show that the black-hole/wormhole transition is characterized by echoes, while the memory of the black hole state is kept in the time-domain profile of the wormhole perturbation at the initial stage of the exponential fall off. Calculations of quasinormal modes with the help of the WKB method with Pade expansion and time-domain integration are in a good agreement. An analytical formula for quasinormal modes in the eikonal regime is obtained.
- [61] arXiv:1911.11844 (cross-list from hep-ph) [pdf, other]
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Title: Freeze-in production of dark matter through spin-1 and spin-2 portalsAuthors: Maíra DutraComments: Conference proceedings paper for the XXIX International Symposium on Lepton Photon Interactions at High Energies (August 5-10, 2019 - Toronto, Canada), based on arXiv:1806.00016[hep-ph] and arXiv:1803.01866[hep-ph]Journal-ref: PoS(LeptonPhoton2019)076Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
In this conference, I have talked about two scenarios in which the out-of-equilibrium production of dark matter (DM) particles in the early universe is unavoidable. In the first one \cite{bhattacharyya_freezing-dark_2018}, we extend the standard model (SM) of particle physics by an extra $U(1)$ gauge group under which all the SM particles are neutral. We then consider DM candidates interacting only with the new spin-1 gauge boson, a heavy $Z^\prime$. We assume the presence of heavy beyond the SM fermions charged under both extra $U(1)$ and SM $SU(3)_c$, allowing for a feeble connection between DM and gluons. In the second scenario \cite{bernal_spin-2_2018}, we assume that the interactions between DM and SM particles are only mediated by gravitons and massive spin-2 fields, being therefore suppressed by the Planck and some intermediate scales, respectively. In both models, we show that the SM particles are able to produce the right amount of DM candidates via freeze-in at most in the early stages of the radiation era, for DM mass in the range $10^{-3}-10^{14}$ GeV. We have shown that if heavy mediators were produced on-shell within a period of entropy production in the early universe, as in the post-inflationary reheating, the DM relic density may be enhanced by many orders of magnitude relative to the usual instantaneous reheating approximation.
- [62] arXiv:1911.11862 (cross-list from hep-ph) [pdf, other]
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Title: The moduli portal to dark matter particlesAuthors: Maíra DutraComments: Conference proceedings paper for the XI Symposium Quantum Theory and Symmetries (QTS-XI) (July 1-5, 2019 - Montreal, Canada), based on arXiv:1811.01947[hep-ph]; Under revisionSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The out-of-equilibrium production of dark matter (DM) from standard model (SM) species in the early universe (freeze-in mechanism) is expected in many scenarios in which very heavy beyond the SM fields act as mediators. In this conference, I have talked about the freeze-in of scalar, fermionic and vector DM though the exchange of moduli fields \cite{chowdhury_moduli_2019}, which are in the low-energy spectrum of many extra-dimensions and string theory frameworks. We have shown that the high-temperature dependencies of the production rate densities in this model, as well as the possibility of having moduli masses at the post-inflationary reheating scale, make it crucial to consider the contribution of the freeze-in prior the start of the standard radiation era for a correct prediction of the DM relic density.
- [63] arXiv:1911.11885 (cross-list from hep-ph) [pdf, other]
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Title: New Perspectives on Axion Misalignment MechanismComments: 7 pages, 7 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
A zero initial velocity of the axion field is assumed in the conventional misalignment mechanism. We propose an alternative scenario where the initial velocity is nonzero, which may arise from an explicit breaking of the PQ symmetry in the early Universe. We demonstrate that, depending on the specifics about the initial velocity and the time order of the PQ symmetry breaking vs. inflation, this new scenario can alter the conventional prediction for the axion relic abundance in different, potentially significant ways. As a result, new viable parameter regions for axion dark matter may open up.
- [64] arXiv:1911.12026 (cross-list from gr-qc) [pdf, ps, other]
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Title: Novel matter coupling in Einstein gravityComments: 19 pages, no figureSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
A novel type of matter coupling in the Einstein gravity is discovered. This type of matter coupling is theoretically self-consistent in the sense that all constraints in the Hamiltonian are preserved to be first class. At low energy scale it recovers the classic standard predictions of the Einstein gravity minimally coupled with matter content, including the gravitational potential and the equivalence principle, while at the high energy scale much richer phenomenology is granted. We predict a lower bound on the cross section between dark matter particles and Standard Model particles in this framework. The novel matter coupling may provide a resolution to the cosmological singularity problem.
- [65] arXiv:1911.12066 (cross-list from hep-ph) [pdf, other]
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Title: Particle emission and gravitational radiation from cosmic strings: observational constraintsComments: 14 pages, 7 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We account for particle emission and gravitational radiation from cosmic string loops to determine their effect on the loop distribution and observational signatures of strings. The effect of particle emission is that the number density of loops no longer scales. This results in a high frequency cutoff on the stochastic gravitational wave background, but we show that the expected cutoff is outside the range of current and planned detectors. Particle emission from string loops also produces a diffuse gamma ray background that is sensitive to the presence of kinks and cusps on the loops. However, both for kinks and cusps, and with mild assumptions about particle physics interactions, current diffuse gamma-ray background observations do not constrain $G\mu$.
- [66] arXiv:1911.12130 (cross-list from hep-ph) [pdf, other]
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Title: Higgs emerging from the darkComments: 6 pages, 1 figure, 1 tableSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Experiment (hep-ex)
We propose a new non-thermal mechanism of dark matter production based on vacuum misalignment. A global $X$-charge asymmetry is generated at high temperatures, under which both the will-be Higgs and the dark matter are charged. At lower energies, the vacuum changes alignment and breaks the U(1)$_X$, leading to the emergence of the Higgs and of a fraction of charge asymmetry stored in the stable dark matter relic. This mechanism can be present in a wide variety of models based on vacuum misalignment, and we demonstrate it in a composite Higgs template model, where all the necessary ingredients are naturally present. A light pseudo-scalar is always predicted, with interesting implications for cosmology and future supernova observations.
- [67] arXiv:1911.12244 (cross-list from hep-ph) [pdf]
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Title: Aspects of astrophysical particle production and beyond the Standard Model phenomenologyAuthors: Matthias VereeckenComments: PhD thesis, 463 pages. Based on the publications arXiv:1506.08803, arXiv:1608.00028 and arXiv:1612.02648, which have been updated using more recent data, as well as currently unpublished work on obscured neutrino sources (Chapter 4)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE)
This PhD thesis deals with various aspects of (astro)particle physics phenomenology and consists out of two parts: beyond the Standard Model physics and neutrino astronomy. In the first part, I focus on beyond the Standard Model physics at the Large Hadron collider. Concretely, I discuss the interpretation of a 2015 excess seen by ATLAS in events with jets, missing transverse momentum and 2 same-flavour, opposite-charge leptons within a model of gauge-mediated supersymmetry breaking. Our model, which features supersymmetry breaking in multiple hidden sectors, was able to explain the 2015 data because of the appearance of an additional massive neutral particle at the bottom of the spectrum, with couplings dictated by supersymmetry. However, using more recent data, I show that this specific implementation of the model is now ruled out. In the second part, I focus on astroparticle physics and neutrino astronomy. This part consists of two projects. The first and largest of these investigates the possibility that the neutrinos seen by IceCube are produced by sources obscured by matter. We show that, in this case, existing bounds from the extragalactic gamma-ray background can be evaded. In addition, we apply our model to a set of sources selected for possible obscuration and obtain relevant bounds on the parameter space. In the final project, I investigate current constraints on neutrino emission from binary black hole mergers. While no such neutrinos are typically expected, current constraints are not yet able to rule out a substantial contribution of such events to the astrophysical neutrino flux. I show that in the near future, this possibility will be constrained. Both parts are preceded by an extensive introduction and review of their respective fields, written to be of general interest.
- [68] arXiv:1911.12277 (cross-list from cond-mat.mtrl-sci) [pdf, other]
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Title: A method for the experimental measurement of bulk and shear loss angles in amorphous thin filmsAuthors: Gabriele Vajente, Mariana Fazio, Le Yang, Anchal Gupta, Alena Ananyeva, Garilynn Billingsley, Carmen S. MenoniSubjects: Materials Science (cond-mat.mtrl-sci); Instrumentation and Methods for Astrophysics (astro-ph.IM); General Relativity and Quantum Cosmology (gr-qc); Instrumentation and Detectors (physics.ins-det)
Brownian thermal noise is a limiting factor for the sensitivity of many high precision metrology applications, among other gravitational wave detectors. The origin of Brownian noise can be traced down to internal friction in the amorphous materials that are used for the high reflection coatings. To properly characterize the internal friction in an amorphous material, one needs to consider the energy losses in the bulk and shear modes. In most of previous works the two loss angles were considered equal, although without any first principle motivation. In this work we show how it is possible to use current state-of-the-art coating ring-down measurement systems to extract the material bulk and shear loss angles. We also show that for titania-doped-tantala, a material commonly used in gravitational wave detector coatings, the experimental data strongly favor a model with two different and distinct loss angles, over the simpler case of one single loss angle.
- [69] arXiv:1911.12302 (cross-list from physics.geo-ph) [pdf, ps, other]
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Title: Non-negligible Oscillation Effects in the Crustal Geo-neutrino CalculationsComments: 15 pages, 4 figuresSubjects: Geophysics (physics.geo-ph); Earth and Planetary Astrophysics (astro-ph.EP); High Energy Physics - Phenomenology (hep-ph)
Accurate prediction of geo-neutrinos from the crust serves as a necessary prerequisite in determination of the geo-neutrino flux from the mantle. In this work, we report the non-negligible oscillation effect in the calculation of the crustal geo-neutrinos, which is usually approximated as a constant average in the previous calculations. An underestimate of around 1-2 TNU for the geo-neutrino signal is observed because of the oscillatory behavior within the local crustal region of around 300 km. Besides, the signal correction given by the Mikheyev-Smirnov-Wolfenstein oscillation from that based on vacuum oscillation is around 0.1%-0.3% for the local crust. This work reminds that the exact oscillation possibility in matter should be considered for future prediction of the local crustal geo-neutrinos.
- [70] arXiv:1911.12342 (cross-list from hep-ph) [pdf, other]
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Title: Asymmetric Matters from a Dark First-Order Phase TransitionComments: 6+2 pages, 1 figureSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We introduce a model for matters-genesis in which both the baryonic and dark matter asymmetries originate from a first-order phase transition in a dark sector with an $SU(3) \times SU(2) \times U(1)$ gauge group and minimal matter content. In the simplest scenario, we predict that dark matter is a dark neutron with mass either $m_n = 1.33$ GeV or $m_n = 1.58$ GeV. Alternatively, dark matter may be comprised of equal numbers of dark protons and pions. This model, in either scenario, is highly discoverable through both dark matter direct detection and dark photon search experiments. The strong dark matter self interactions may ameliorate small-scale structure problems, while the strongly first-order phase transition may be confirmed at future gravitational wave observatories.
Replacements for Thu, 28 Nov 19
- [71] arXiv:1802.03990 (replaced) [pdf, other]
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Title: Improving baryon acoustic oscillation measurement with the combination of cosmic voids and galaxiesAuthors: Cheng Zhao, Chia-Hsun Chuang, Francisco-Shu Kitaura, Yu Liang, Marcos Pellejero-Ibanez, Charling Tao, Mariana Vargas-Magaña, Andrei Variu, Gustavo YepesComments: 21 pages, 22 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [72] arXiv:1804.07325 (replaced) [pdf, other]
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Title: AWARE: An algorithm for the automated characterization of EUV waves in the solar atmosphereAuthors: Jack Ireland, Andrew R. Inglis, Albert Y. Shih, Steven Christe, Stuart J. Mumford, Laura A. Hayes, Barbara J. Thompson, V. Keith HughittJournal-ref: Solar Physics (2019), 294, 158Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
- [73] arXiv:1811.01572 (replaced) [pdf, ps, other]
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Title: Non-Fourier description of heat flux evolution in 3D MHD simulations of the solar coronaAuthors: Jörn Warnecke (1), Sven Bingert (2) ((1) Max-Planck-Institut für Sonnensystemforschung, (2) Gesellschaft für wissenschaftliche Datenverarbeitung mbH Göttingen)Comments: 19 pages, 9 figures, published in GAFD special issue on "Physics and Algorithms of the Pencil Code"Journal-ref: Geophys. Astrophys. Fluid Dyn. 114, 261-281 (2020)Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
- [74] arXiv:1901.00900 (replaced) [pdf, ps, other]
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Title: High-Precision Dark Halo Virial Masses from Globular Cluster Numbers: Implications for Globular Cluster Formation and Galaxy AssemblyComments: 11 pages, 4 figures, ApJ in pressSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [75] arXiv:1901.10483 (replaced) [pdf, other]
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Title: Gamma Lines from the Hidden SectorComments: to appear in PRDSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Experiment (hep-ex)
- [76] arXiv:1902.08212 (replaced) [pdf, other]
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Title: Relaxion Stars and their detection via Atomic PhysicsComments: 17 pages, 6 figures; v2: minor revisions, matches published versionSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Atomic Physics (physics.atom-ph)
- [77] arXiv:1903.12253 (replaced) [pdf, other]
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Title: Baryon density extraction and isotropy analysis of Cosmic Microwave Background using Deep LearningComments: 6 pages, cosmic microwave background radiation, deep learning, multilayer perceptronSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [78] arXiv:1904.03790 (replaced) [pdf, other]
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Title: Revisiting Metastable Dark Energy and Tensions in the Estimation of Cosmological ParametersComments: 13 pages, 11 figures, accepted for publication in ApJSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [79] arXiv:1904.07596 (replaced) [pdf, ps, other]
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Title: Orbital decay of short-period gas giants under evolving tidesComments: Published in Monthly Notices of the Royal Astronomical Society. 12 pages, 6 figuresJournal-ref: Monthly Notices of the Royal Astronomical Society, Volume 486, Issue 3, July 2019, Pages 3963-3974Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [80] arXiv:1904.09121 (replaced) [pdf, other]
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Title: Secondary CMB temperature anisotropies from magnetic reheatingComments: 10 pages, 3 figuresJournal-ref: MNRAS 490, no3 4419 (2019)Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
- [81] arXiv:1904.12878 (replaced) [pdf, other]
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Title: Gravitational Waves Induced by Scalar Perturbations during a Gradual Transition from an Early Matter Era to the Radiation EraComments: 14 pages, 5 figures, a minor correction in Eq.(3.9) after the published version which does not affect the resultsSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
- [82] arXiv:1906.08275 (replaced) [pdf, other]
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Title: A Simple Phenomenological Emergent Dark Energy Model can Resolve the Hubble TensionComments: 7 pages, 4 figures, 1 table, published in ApJLSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
- [83] arXiv:1906.10041 (replaced) [pdf, ps, other]
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Title: Generation of a large-scale vorticity in a fast rotating density stratified turbulence or turbulent convectionComments: 13 pages, revtex-4, final versionSubjects: Fluid Dynamics (physics.flu-dyn); Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
- [84] arXiv:1906.10455 (replaced) [pdf, other]
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Title: The XXL Survey: XXXVIII. Scatters and correlations of X-ray proxies in the bright XXL cluster sampleAuthors: Mauro Sereno (INAF-OAS), Stefano Ettori, Dominique Eckert, Paul Giles, Ben J. Maughan, Florian Pacaud, Marguerite Pierre, Patrick ValageasComments: 19 pages, in press on Astronomy and Astrophysics; v02: updated XXL series numberSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [85] arXiv:1907.03775 (replaced) [pdf, other]
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Title: Screened Fifth Forces Mediated by Dark Matter-Baryon Interactions: Theory and Astrophysical ProbesComments: 19 pages, 8 figures; updated to reflect published version. Minor changes as a result of the refereeing processJournal-ref: Phys.Rev. D100 (2019) no.10, 104035Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
- [86] arXiv:1907.08094 (replaced) [pdf, other]
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Title: The galaxy bias at second order in general relativity with Non-Gaussian initial conditionsComments: 1+14+4 pages, two figures. Version accept for publication by JCAPSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
- [87] arXiv:1907.11101 (replaced) [pdf, other]
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Title: The Cosmological Consistency Relation in a Universe with StructureComments: 11 pages, 3 figures, version accepted for publication in JCAPSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
- [88] arXiv:1907.13184 (replaced) [pdf, other]
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Title: Some Implications of the Leptonic Annihilation of Dark Matter: Possible Galactic Radio Emission Signatures and the Excess Radio Flux of Extragalactic OriginComments: 18 pages, 28 figures. Version accepted for publicationSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE)
- [89] arXiv:1908.04794 (replaced) [pdf, other]
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Title: Predicting Ly$α$ Emission from Galaxies via Empirical Markers of Production and Escape in the KBSSAuthors: Ryan F. Trainor, Allison L. Strom, Charles C. Steidel, Gwen C. Rudie, Yuguang Chen, Rachel L. TheiosComments: 24 pages, 9 figures, accepted by ApJSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [90] arXiv:1908.07049 (replaced) [pdf, other]
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Title: Upgraded antennas for pulsar observations in the Argentine Institute of Radio astronomyAuthors: G. Gancio, C.O. Lousto, L. Combi, S. del Palacio, F.G. López Armengol, J.A. Combi, F. García, P. Kornecki, A.L. Müller, E. Gutierrez, F. Hauscarriaga, G. C.MancusoComments: 13 pages, 12 figures, some important revisions includedSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
- [91] arXiv:1908.08765 (replaced) [pdf, ps, other]
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Title: Reduction of the Uncertainty in the Atmospheric Neutrino Flux Prediction Below 1 GeV Using Accurately Measured Atmospheric Muon FluxComments: 14 pages, 30 fuguresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [92] arXiv:1908.10865 (replaced) [pdf, other]
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Title: Atmospheric Cherenkov Telescopes as a Potential Veto Array for Neutrino AstronomyAuthors: D. Rysewyk, D. Lennarz, T. DeYoung, J. Auffenberg, M. Schaufel, T. Bretz, C. Wiebusch, M. U. NisaComments: 33 pages, 10 figures. Accepted by Astropart. PhysSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Experiment (hep-ex)
- [93] arXiv:1908.10882 (replaced) [pdf, ps, other]
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Title: Neutrino Emissions from Tidal Disruption RemnantsComments: 41 pages, 2 figures, published in ApJ, 886 114 (2019)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
- [94] arXiv:1908.10969 (replaced) [pdf, other]
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Title: Tilting Ice Giants with a Spin-Orbit ResonanceComments: 23 pages, 8 figures, accepted for publication in ApJSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [95] arXiv:1909.01841 (replaced) [pdf, other]
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Title: Neutrino oscillations in a neutrino-dominated accretion disk around a Kerr BHComments: 51 pages, 9 figures. SubmittedSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [96] arXiv:1909.07011 (replaced) [pdf, other]
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Title: The impact of (n,$γ$) reaction rate uncertainties on the predicted abundances of i-process elements with $32\leq Z\leq 48$ in the metal-poor star HD94028Authors: John E. McKay (UVic, TRIUMF), Pavel A. Denissenkov (UVic), Falk Herwig (UVic), Georgios Perdikakis (CMU), Hendrik Schatz (MSU)Comments: 10 pages, 14 figures, 1 table, accepted for publication by MNRASSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
- [97] arXiv:1909.09655 (replaced) [pdf, other]
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Title: Circumplanetary Disk Dynamics in the Isothermal and Adiabatic LimitsComments: Accepted to ApJSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [98] arXiv:1910.01649 (replaced) [pdf, other]
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Title: Refined Bounds on MeV-scale Thermal Dark Sectors from BBN and the CMBComments: 28 pages, 10 figures, 7 tables. v2. References and minor clarifications added. Matches published version in JCAPSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [99] arXiv:1910.02547 (replaced) [pdf, other]
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Title: Initial Characterization of Interstellar Comet 2I/2019 Q4 (Borisov)Comments: 22 pages, 5 figures, 3 tablesSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [100] arXiv:1910.05687 (replaced) [pdf, other]
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Title: Constraining the magnetic field structure in collisionless relativistic shocks with a radio afterglow polarization upper limit in GW170817Comments: 11 pages, 6 figures, Accepted to MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [101] arXiv:1910.07760 (replaced) [pdf, ps, other]
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Title: What would happen if we were about 1 pc away from a supermassive black hole?Authors: Lorenzo IorioComments: LaTex2e, 18 pages, no tables, 3 figures. Version accepted for publication in The Astrophysical Journal (ApJ)Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); General Relativity and Quantum Cosmology (gr-qc); Space Physics (physics.space-ph)
- [102] arXiv:1910.08552 (replaced) [pdf, other]
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Title: Early-type galaxy density profiles from IllustrisTNG: II. Evolutionary trend of the total density profileAuthors: Yunchong Wang (1,2), Mark Vogelsberger (1), Dandan Xu (2), Xuejian Shen (3), Shude Mao (2,4), David Barnes (1), Hui Li (1), Federico Marinacci (5), Paul Torrey (6), Volker Springel (7), Lars Hernquist (8) ((1) MIT, (2) Tsinghua, (3) Caltech, (4) NAOC, (5) UNIBO, (6) UF, (7) MPA, (8) Harvard)Comments: 19 pages, 8 figures, 4 tables. Accepted for publication in MNRAS, updated to match published versionJournal-ref: Monthly Notices of the Royal Astronomical Society, Volume 490, Issue 4, December 2019, Pages 5722-5738Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [103] arXiv:1910.10389 (replaced) [pdf, other]
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Title: Radial-velocity jitter of stars as a function of observational timescale and stellar ageComments: 15 pages, 7 Figures; Changelog v2: Updated link to CDS for table E.1; rearranged Fig. 2 to match journal layoutJournal-ref: A&A 632, A37 (2019)Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
- [104] arXiv:1910.12547 (replaced) [pdf, other]
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Title: The Effects of Potential Shape on Inhomogenous InflationComments: 16 pages, 12 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
- [105] arXiv:1910.14291 (replaced) [pdf, other]
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Title: Measurement of Apparent Magnitude and Effective Temperature with Amateur TelescopesSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
- [106] arXiv:1910.14414 (replaced) [pdf, ps, other]
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Title: Preferred-frame Effects, the $H_0$ Tension, and Probes of Hořava-Lifshitz GravityAuthors: Nils A. NilssonComments: Thoroughly revised, new material added, typos fixed, references added. 17 pages, no figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [107] arXiv:1911.00299 (replaced) [pdf, other]
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Title: The Interaction Of AGN Jets With ObstaclesAuthors: Núria Torres-AlbàComments: Conference proceedings (HEPRO VII). 11 pages, 3 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [108] arXiv:1911.06040 (replaced) [pdf, ps, other]
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Title: Cuscuton gravity as a classically stable limiting curvature theoryComments: 23 pages; v2: minor changes, references addedSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
- [109] arXiv:1911.09050 (replaced) [pdf, ps, other]
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Title: A Note on the Swampland Distance ConjectureComments: 6 pages, new revised version and title changedSubjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
- [110] arXiv:1911.09434 (replaced) [pdf, other]
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Title: Probing the Properties of the Pulsar Wind in the Gamma-Ray Binary HESS J0632+057 with NuSTAR and VERITAS ObservationsAuthors: A. Archer, W. Benbow, R. Bird, A. Brill, R. Brose, M. Buchovecky, J. L. Christiansen, A. J. Chromey, W. Cui, A. Falcone, Q. Feng, J. P. Finley, L. Fortson, A. Furniss, A. Gent, G. H. Gillanders, C. Giuri, O. Gueta, D. Hanna, T. Hassan, O. Hervet, J. Holder, G. Hughes, T. B. Humensky, P. Kaaret, N. Kelley-Hoskins, M. Kertzman, D. Kieda, M. Krause, M. J. Lang, G. Maier, P. Moriarty, R. Mukherjee, D. Nieto, M. Nievas-Rosillo, S. O'Brien, R. A. Ong, A. N. Otte, N. Park, A. Petrashyk, K. Pfrang, M. Pohl, R. R. Prado, E. Pueschel, J. Quinn, K. Ragan, P. T. Reynolds, D. Ribeiro, G. T. Richards, E. Roache, I. Sadeh, M. Santander, S. Schlenstedt, G. H. Sembroski, I. Sushch, A. Weinstein, P. Wilcox, A. Wilhelm, D. A. Williams, T. J Williamson, C. J. Hailey, S. Mandel, K. MoriComments: Accepted for publication in The Astrophysical JournalSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [111] arXiv:1911.10318 (replaced) [pdf, ps, other]
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Title: The circumstellar environment around the embedded protostar EC 53Comments: 28 pages, 15 figures, 2 tables, accepted for publication in ApJSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
- [112] arXiv:1911.10756 (replaced) [pdf, ps, other]
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Title: The extended molecular envelope of the asymptotic giant branch star $π^{1}$ Gruis as seen by ALMA II. The spiral-outflow observed at high-angular resolutionAuthors: L. Doan, S. Ramstedt, W. H. T. Vlemmings, S. Mohamed, S. Höfner, E. De Beck, F. Kerschbaum, M. Lindqvist, M. Maercker, C. Paladini, M. WittkowskiComments: 12 pages, 11 figuresSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
- [113] arXiv:1911.11586 (replaced) [pdf, ps, other]
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Title: Cascade disruptions in asteroid clustersSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [114] arXiv:1911.11588 (replaced) [pdf, other]
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Title: The Diffuse Ionized Gas Halo of the Small Magellanic CloudComments: 16 pages, 8 figures, 3 tablesSubjects: Astrophysics of Galaxies (astro-ph.GA)
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