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New submissions for Mon, 27 Apr 20

[1]  arXiv:2004.11378 [pdf, other]

Title: SENSEI: Direct-Detection Results on sub-GeV Dark Matter from a New Skipper-CCD

Authors: Liron Barak, Itay M. Bloch, Mariano Cababie, Gustavo Cancelo, Luke Chaplinsky, Fernando Chierchie, Michael Crisler, Alex Drlica-Wagner, Rouven Essig, Juan Estrada, Erez Etzion, Guillermo Fernandez Moroni, Daniel Gift, Sravan Munagavalasa, Aviv Orly, Dario Rodrigues, Aman Singal, Miguel Sofo Haro, Leandro Stefanazzi, Javier Tiffenberg, Sho Uemura, Tomer Volansky, Tien-Tien Yu

Comments: 5 pages, 4 figures, 1 table + Supplemental Materials (4 pages, 6 figures) + References

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph); Instrumentation and Detectors (physics.ins-det)

We present the first direct-detection search for eV-to-GeV dark matter using a new ~2-gram high-resistivity Skipper-CCD from a dedicated fabrication batch that was optimized for dark-matter searches. Using 24 days of data acquired in the MINOS cavern at the Fermi National Accelerator Laboratory, we measure the lowest rates in silicon detectors of events containing one, two, three, or four electrons, and achieve world-leading sensitivity for a large range of sub-GeV dark matter masses. Data taken with different thicknesses of the detector shield suggest a correlation between the rate of high-energy tracks and the rate of single-electron events previously classified as "dark current." We detail key characteristics of the new Skipper-CCDs, which augur well for the planned construction of the ~100-gram SENSEI experiment at SNOLAB.

[2]  arXiv:2004.11379 [pdf, other]

Title: Impacts of Dust Grains Accelerated by Supernovae on the Moon

Authors: Amir Siraj, Abraham Loeb

Comments: 4 pages, 2 figures; submitted for publication

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

There is evidence that ejecta from nearby supernovae have rained down on Earth in the past. Supernovae can accelerate pre-existing dust grains in the interstellar medium to speeds of $\sim 0.01 \mathrm{\;c}$. We investigate the survival and impact of dust grains from supernovae on the moon, finding that supernova dust grains can form detectable tracks with widths of $\sim 0.01 - 0.07 \mathrm{\; \mu m}$ and depths of $\sim 0.1 - 0.7 \mathrm{\; mm}$ in lunar rocks. These tracks could potentially shed light on the timings, luminosities, and directions of nearby supernovae.

[3]  arXiv:2004.11382 [pdf, other]

Title: The Bulge Radial Velocity Assay for RR Lyrae stars (BRAVA-RR) DR2: a Bimodal Bulge?

Authors: Andrea Kunder, Angeles Perez-Villegas, R. Michael Rich, Jonathan Ogata, Emma Murari, Emilie Boren, Christian I. Johnson, David Nataf, Alistair Walker, Giuseppe Bono, Andreas Koch, Roberto De Propris, Jesper Storm, Jennifer Wojno

Comments: accepted for publication in the Astronomical Journal

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

Radial velocities of 2768 fundamental mode RR Lyrae stars (RRLs) toward the Southern Galactic bulge are presented, spanning the southern bulge from -8 < l < +8 and -3 < b <-6. Distances derived from the pulsation properties of the RRLs are combined with Gaia proper motions to give constraints on the orbital motions of 1389 RRLs. The majority (~75%) of the bulge RRLs have orbits consistent with these stars being permanently bound to <3.5 kpc from the Galactic Center, similar to the bar. However, unlike the bulge giants, the RRLs exhibit slower rotation and a higher velocity dispersion. The higher velocity dispersion arises almost exclusively from halo interlopers passing through the inner Galaxy. We present 82 stars with space velocities > 500 km/s and find that the majority of these high-velocity stars are halo interlopers; it is unclear if a sub-sample of these stars with similar space velocities have a common origin. Once the 25% of the sample represented by halo interlopers is cleaned, we can clearly discern two populations of bulge RRLs in the inner Galaxy. One population of RRLs is not as tightly bound to the Galaxy (but is still confined to the inner ~3.5 kpc), and is both spatially and kinematically consistent with the barred bulge. The second population is more centrally concentrated and does not trace the bar. One possible interpretation is that this population was born prior to bar formation, as its spatial location, kinematics and pulsation properties suggest, possibly from an accretion event at high redshift.

[4]  arXiv:2004.11384 [pdf, other]

Title: Timing the Early Assembly of the Milky Way with the H3 Survey

Authors: Ana Bonaca, Charlie Conroy, Phillip A. Cargile, Rohan P. Naidu, Benjamin D. Johnson, Dennis Zaritsky, Yuan-Sen Ting, Nelson Caldwell, Jiwon Jesse Han, Pieter van Dokkum

Comments: submitted to AAS Journals

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

The archaeological record of stars in the Milky Way opens a uniquely detailed window into the early formation and assembly of galaxies. Here we use 11,000 main-sequence turn-off stars with well-measured ages, [Fe/H], [$\alpha$/Fe], and orbits from the H3 Survey and Gaia to time the major events in the early Galaxy. Located beyond the Galactic plane, $1\lesssim |Z|/\rm kpc \lesssim4$, this sample contains three chemically distinct groups: a low metallicity population, and low-$\alpha$ and high-$\alpha$ groups at higher metallicity. The age and orbit distributions of these populations show that: 1) the high-$\alpha$ group, which includes both disk stars and the in-situ halo, has a star-formation history independent of eccentricity that abruptly truncated $8.3\pm0.1$ Gyr ago ($z\simeq1$); 2) the low metallicity population, which we identify as the accreted stellar halo, is on eccentric orbits and its star formation truncated $10.2.^{+0.2}_{-0.1}$ Gyr ago ($z\simeq2$); 3) the low-$\alpha$ population is primarily on low eccentricity orbits and the bulk of its stars formed less than 8 Gyr ago. These results suggest a scenario in which the Milky Way accreted a satellite galaxy at $z\approx2$ that merged with the early disk by $z\approx1$. This merger truncated star formation in the early high-$\alpha$ disk and perturbed a fraction of that disk onto halo-like orbits. The merger enabled the formation of a chemically distinct, low-$\alpha$ disk at $z\lesssim1$. The lack of any stars on halo-like orbits at younger ages indicates that this event was the last significant disturbance to the Milky Way disk.

[5]  arXiv:2004.11387 [pdf, other]

Title: Optimal void finders in weak lensing maps

Authors: Christopher T. Davies (Durham ICC), Enrique Paillas (Católica), Marius Cautun (Leiden), Baojiu Li (Durham ICC)

Comments: 25 pages, 10 figures, submitted to MNRAS

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

Cosmic voids are a key component of the large-scale structure that contain a plethora of cosmological information. Typically, voids are identified from the underlying galaxy distribution, which is a biased tracer of the total matter field. Previous works have shown that 2D voids identified in weak lensing maps -- weak lensing voids -- correspond better to true underdense regions along the line of sight. In this work, we study how the properties of weak lensing voids depend on the choice of void finder, by adapting several popular void finders. We present and discuss the differences between identifying voids directly in the convergence maps, and in the distribution of weak lensing peaks. Particular effort has been made to test how these results are affected by galaxy shape noise, which is a dominant source of noise in weak lensing observations. By studying the signal-to-noise ratios (SNR) for the tangential shear profile of each void finder, we find that voids identified directly in the convergence maps have the highest SNR but are also the ones most affected by galaxy shape noise. Troughs are least affected by noise, but also have the lowest SNR. The tunnel algorithm, which identifies voids in the distribution of weak lensing peaks, represents a good compromise between finding a large tangential shear SNR and mitigating the effect of galaxy shape noise.

[6]  arXiv:2004.11388 [pdf, other]

Title: Ultra-diffuse galaxies in the Coma cluster: Probing their origin and AGN occupation fraction

Authors: Orsolya E. Kovacs, Akos Bogdan, Rebecca E. A. Canning

Comments: 11 pages, 6 figures, submitted to ApJ

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

Ultra-diffuse galaxies (UDGs) exhibit low surface brightness, but their optical extent is comparable to Milky Way-type galaxies. Due to their peculiar properties, it remains ambiguous whether UDGs are the descendants of massive galaxies or they are puffed-up dwarf galaxies. In this work, we explore a population of 404 UDGs in the Coma cluster to study their origin and AGN occupation fraction. To constrain the formation scenario of UDGs, we probe the X-ray emission originating from diffuse gas and from the population of unresolved low-mass X-ray binaries (LMXBs) residing in globular clusters (GCs). It is expected that both the luminosity of the hot gas and the number of globular clusters and hence the luminosity from GC-LMXBs are proportional to the total dark matter halo mass. We do not detect statistically significant emission from the hot gas or from GC-LMXBs. The upper limits on the X-ray luminosities suggest that the bulk of the UDGs reside in low-mass dark matter halos, implying that they are genuine dwarf galaxies. This conclusion agrees with our previous results obtained for isolated UDGs, arguing that UDGs are a homogenous population of galaxies. To probe the AGN occupation fraction of UDGs, we cross-correlate the position of detected X-ray sources in the Coma cluster with the position of UDGs. We identify two UDGs that have a luminous X-ray source at 3.0" and 3.2" from the center of the galaxies, which could be off-center AGN. However, Monte Carlo simulations suggest that one of these sources could be the result of spatial coincidence with a background AGN. Therefore, we place an upper limit of $\lesssim0.5\%$ on the AGN occupation fraction of UDGs.

[7]  arXiv:2004.11389 [pdf, other]

Title: Lifting the core-collapse supernova bounds on keV-mass sterile neutrinos

Authors: Anna M. Suliga, Irene Tamborra (Niels Bohr Institute), Meng-Ru Wu (Academia Sinica, National Center for Theoretical Sciences)

Comments: 28 pages, 14 figures

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

We explore the energy and entropy transport as well as the lepton number variation induced from the mixing between electron and sterile neutrinos with keV mass in the supernova core. We develop the first radial- and time-dependent treatment of the sterile-electron neutrino mixing, by including ordinary matter effects, reconversions between sterile and electron antineutrinos, as well as the collisional production of sterile particles. The dynamical feedback due to the production of sterile particles on the composition and thermodynamic properties of the core only leads to major implications for the supernova physics for large mixing angles ($\sin^2 2 \theta > 10^{-10}$). Our findings suggest that a self-consistent appraisal of the electron-sterile conversion physics in the supernova core would relax the bounds on the sterile neutrino mixing parameters reported in the literature for mixing angles smaller than $10^{-6}$, leaving the parameter space of the mass and mixing angles of sterile neutrinos relevant to dark matter searches unconstrained by supernovae.

[8]  arXiv:2004.11391 [pdf, ps, other]

Title: Connection of supernovae 2002ap, 2003gd, 2013ej, and 2019krl in M74 with atomic gas accretion and spiral structure

Authors: Michał J. Michałowski, Natalia Gotkiewicz, Jens Hjorth, Peter Kamphuis

Comments: A&A, in press, 7 pages, 5 figures, 1 table

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

Studying the nature of various types of supernovae (SNe) is important for our understanding of stellar evolution. Observations of atomic and molecular gas in the host galaxies of gamma-ray bursts (GRBs) and SNe have recently been used to learn about the nature of the explosions themselves and the star formation events during which their progenitors were born. Based on archival data for M74, which previously has not been investigated in the context of SN positions, we report the gas properties in the environment of the broad-lined type Ic (Ic-BL) SN 2002ap and the type II SNe 2003gd, 2013ej, and 2019krl. The SN 2002ap is located at the end of an off-centre, asymmetric, 55 kpc-long HI extension containing 7.5% of the total atomic gas in M74, interpreted as a signature of external gas accretion. It is the fourth known case of an explosion of a presumably massive star located close to a concentration of atomic gas (after GRBs 980425, 060505, and SN 2009bb). It is unlikely that all these associations are random (at a 3sigma significance), so the case of SN 2002ap adds to the evidence that the birth of the progenitors of type Ic-BL SNe and GRBs is connected with the accretion of atomic gas from the intergalactic medium. The HI extension could come from tidally disrupted companions of M74, or be a remnant of a galaxy or a gas cloud that accreted entirely from the intragroup medium. The other (type II) SNe in M74 are located at the outside edge of a spiral arm. This suggests that either their progenitors were born when gas was piling up there or that the SN progenitors moved away from the arm due to their orbital motions. These type II SNe do not seem to be related to gas accretion.

[9]  arXiv:2004.11394 [pdf, other]

Title: The efficiency of dust trapping in ringed proto-planetary discs

Authors: Giovanni P. Rosotti, Richard Teague, Cornelis Dullemond, Richard A. Booth, Cathie Clarke

Comments: 10 pages, 4 figures; accepted for publication in MNRAS

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

When imaged at high-resolution, many proto-planetary discs show gaps and rings in their dust sub-mm continuum emission profile. These structures are widely considered to originate from local maxima in the gas pressure profile. The properties of the underlying gas structures are however unknown. In this paper we present a method to measure the dust-gas coupling $\alpha/St$ and the width of the gas pressure bumps affecting the dust distribution, applying high-precision techniques to extract the gas rotation curve from emission lines data-cubes. As a proof-of-concept, we then apply the method to two discs with prominent sub-structure, HD163296 and AS 209. We find that in all cases the gas structures are larger than in the dust, confirming that the rings are pressure traps. Although the grains are sufficiently decoupled from the gas to be radially concentrated, we find that the degree of coupling of the dust is relatively good ($\alpha/St \sim 0.1$). We can therefore reject scenarios in which the disc turbulence is very low and the dust has grown significantly. If we further assume that the dust grain sizes are set by turbulent fragmentation, we find high values of the $\alpha$ turbulent parameter ($\alpha \sim 10^{-2}$). Alternatively, solutions with smaller turbulence are still compatible with our analysis if another process is limiting grain growth. For HD163296, recent measurements of the disc mass suggest that this is the case if the grain size is 1mm. Future constraints on the dust spectral indices will help to discriminate between the two alternatives.

[10]  arXiv:2004.11396 [pdf, other]

Title: Constraints on primordial gravitational waves from the Cosmic Microwave Background

Authors: Thomas J. Clarke, Edmund J. Copeland, Adam Moss

Comments: 29 pages, 7 figures, 1 appendix (with 1 figure). Prepared for submission to JCAP

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

Searches for primordial gravitational waves have resulted in constraints in a large frequency range from a variety of sources. The standard Cosmic Microwave Background (CMB) technique is to parameterise the tensor power spectrum in terms of the tensor-to-scalar ratio, $r$, and spectral index, $n_{\rm t}$, and constrain these using measurements of the temperature and polarization power spectra. Another method, applicable to modes well inside the cosmological horizon at recombination, uses the shortwave approximation, under which gravitational waves behave as an effective neutrino species. In this paper we give model-independent CMB constraints on the energy density of gravitational waves, $\Omega_\text{gw} h^2$, for the entire range of observable frequencies. On large scales, $f \lesssim 10^{-16}\, \text{Hz}$, we reconstruct the initial tensor power spectrum in logarithmic frequency bins, finding maximal sensitivity for scales close to the horizon size at recombination. On small scales, $f \gtrsim10^{-15}\,\mbox{Hz}$, we use the shortwave approximation, finding $\Omega_\text{gw} h^2 < 1.7 \times10^{-6}$ for adiabatic initial conditions and $\Omega_\text{gw} h^2 < 2.8 \times10^{-7}$ for homogeneous initial conditions (both $2\sigma$ upper limits). For scales close to the horizon size at recombination, we use second-order perturbation theory to calculate the back-reaction from gravitational waves, finding $\Omega_\text{gw} h^2 < 1.0 \times10^{-6}$.

[11]  arXiv:2004.11397 [pdf, other]

Title: DAYENU: A Simple Filter of Smooth Foregrounds for Intensity Mapping Power Spectra

Authors: Aaron Ewall-Wice, Nicholas Kern, Joshua S. Dillon, Adrian Liu, Aaron Parsons, Saurabh Singh, Adam Lanman, Paul La Plante, Nicolas Fagnoni, Eloy de Lera Acedo, David R. DeBoer, Chuneeta Nunhokee, Philip Bull, Tzu-Ching Chang, T. Joseph Lazio, James Aguirre, Sean Weinberg

Comments: To be submitted to MNRAS, 18 pages, 15 figures

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Methods for Astrophysics (astro-ph.IM)

We introduce DAYENU, a linear, spectral filter for HI intensity mapping that achieves the desirable foreground mitigation and error minimization properties of inverse co-variance weighting with minimal modeling of the underlying data. Beyond 21 cm power-spectrum estimation, our filter is suitable for any analysis where high dynamic-range removal of spectrally smooth foregrounds in irregularly (or regularly) sampled data is required, something required by many other intensity mapping techniques. We show that DAYENU enables the access of large-scale line-of-sight modes that are inaccessible to tapered DFT estimators. Since these modes have the largest SNRs, DAYENU significantly increases the sensitivity of 21 cm analyses over tapered Fourier transforms.
Slight modifications allow us to use DAYENU as a linear replacement for iterative delay CLEANing (DAYENUREST). An interactive jupyter tutorial on using DAYENU can be found at https://github.com/HERA-Team/uvtools/blob/master/examples/linear_clean_demo.ipynb DAYENU's source code can be found at https://github.com/HERA-Team/uvtools/blob/master/uvtools/dspec.py

[12]  arXiv:2004.11402 [pdf, other]

Title: A missing outskirts problem? Comparisons between stellar halos in the Dragonfly Nearby Galaxies Survey and the TNG100 simulation

Authors: Allison Merritt, Annalisa Pillepich, Pieter van Dokkum, Dylan Nelson, Lars Hernquist, Federico Marinacci, Mark Vogelsberger

Comments: Accepted for publication in MNRAS. 33 pages, 18 figures (main text). Key results are shown in Figures 6 and 17

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

Low surface brightness galactic stellar halos provide a challenging but promising path towards unraveling the past assembly histories of individual galaxies. Here, we present detailed comparisons between the stellar halos of Milky Way-mass disk galaxies observed as part of the Dragonfly Nearby Galaxies Survey (DNGS) and stellar mass-matched galaxies in the TNG100 run of the IllustrisTNG project. We produce stellar mass maps as well as mock $g$ and $r$-band images for randomly oriented simulated galaxies, convolving the latter with the Dragonfly PSF and taking care to match the background noise, surface brightness limits and spatial resolution of DNGS. We measure azimuthally averaged stellar mass density and surface brightness profiles, and find that the DNGS galaxies generally have less stellar mass (or light) at large radii (>20 kpc) compared to their mass-matched TNG100 counterparts, and that simulated galaxies with similar surface density profiles tend to have low accreted mass fractions for their stellar mass. We explore potential solutions to this apparent "missing outskirts problem" by implementing several ad-hoc adjustments within TNG100 at the stellar particle level. Although we are unable to identify any single adjustment that fully reconciles the differences between the observed and simulated galaxy outskirts, we find that artificially delaying the disruption of satellite galaxies and reducing the spatial extent of in-situ stellar populations result in improved matches between the outer profile shapes and stellar halo masses, respectively. Further insight can be achieved with higher resolution simulations that are able to better resolve satellite accretion, and with larger samples of observed galaxies.

[13]  arXiv:2004.11418 [pdf, other]

Title: Radio Observations of Magnetic Cataclysmic Variables

Authors: Paul Barrett, Christopher Dieck, Anthony J. Beasley, Paul A Mason, Kulinder P. Singh

Comments: 16 pages, 5 figures, Invited talk for COSPAR 42nd General Assembly, Pasadena, CA

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

The NSF's Karl G. Jansky Very Large Array (VLA) is used to observe 122 magnetic cataclysmic variables (MCVs) during three observing semesters (13B, 15A, and 18A). We report radio detections of 33 stars with fluxes in the range 6--8031 uJy. Twenty-eight stars are new radio sources, increasing the number of radio detected MCVs to more that 40. A surprising result is that about three-quarters (24 of 33 stars) of the detections show highly circularly polarized radio emission of short duration, which is characteristic of electron cyclotron maser emission. We argue that this emission originates from the lower corona of the donor star, and not from a region between the two stars. Maser emission enables a more direct estimate of the mean coronal magnetic field of the donor star, which we estimate to be 1--4 kG assuming a magnetic filling factor of 50%. A two-sample Kolmogorov-Smirnov test supports the conclusion that the distribution function of radio detected MCVs with orbital periods between 1.5-5 hours is similar to that of all MCVs. This result implies that rapidly-rotating (Pspin < 10 days), fully convective stars can sustain strong magnetic dynamos. These results support the model of Taam & Spruit (1989) that the change in angular momentum loss across the fully convective boundary at Porb = ~3 hours is due to a change in the magnetic field structure of the donor star from a low-order to high-order multipolar field.

[14]  arXiv:2004.11442 [pdf, other]

Title: Cosmic evolution of molecular gas mass density from an empirical relation between $\rm L_{1.4GHz}$ and $\rm L^{\prime}_{CO}$

Authors: G. Orellana-González, E. Ibar, R. Leiton, A. P. Thomson, C. Cheng, R. J. Ivison, R. Herrera-Camus, H. Messias, P. Calderón-Castillo, T. M. Hughes, L. Leeuw

Comments: 11 Pages, 5 figures

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

Historically, GHz radio emission has been used extensively to characterize the star-formation activity in galaxies. In this work, we look for empirical relations amongst the radio luminosity, the infrared luminosity, and the CO-based molecular gas mass. We assemble a sample of 278 nearby galaxies with measurements of radio continuum and total infrared emission, and the $^{12}$CO (J = 1-0) emission line. We find a correlation between the radio continuum and the CO emission line (with a scatter of 0.36 dex), in a large sample of different kind of galaxies. Making use of this correlation, we explore the evolution of the molecular gas mass function and the cosmological molecular gas mass density in six redshift bins up to $z = 1.5$. These results agree with previous semi-analytic predictions and direct measurements: the cosmic molecular gas density increases up to $z=1.5$. In addition, we find a single plane across five orders of magnitude for the explored luminosities, with a scatter of 0.27 dex. These correlations are sufficiently robust to be used for samples where no CO measurements exist.

[15]  arXiv:2004.11444 [pdf, other]

Title: EMPRESS. III. Morphology, Stellar Population, and Dynamics of Extremely Metal Poor Galaxies (EMPGs): Are EMPGs Local Analogs of High-$z$ Young Galaxies?

Authors: Yuki Isobe, Masami Ouchi, Takashi Kojima, Takatoshi Shibuya, Kohei Hayashi, Michael Rauch, Shotaro Kikuchihara, Haibin Zhang, Yoshiaki Ono, Seiji Fujimoto, Yuichi Harikane, Ji Hoon Kim, Yutaka Komiyama, Haruka Kusakabe, Chien-Hsiu Lee, Ken Mawatari, Masato Onodera, Yuma Sugahara, Kiyoto Yabe

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

We present the morphology and stellar population of 27 extremely metal poor galaxies (EMPGs) at $z\sim0$ with metallicities of $0.01-0.1$ Z$_{\odot}$. We conduct multi-component surface brightness (SB) profile fitting for the deep Subaru/HSC $i$-band images of the EMPGs with the Galfit software, carefully removing the SB contributions of potential associated galaxies (PAGs). We find that the EMPGs with a median stellar mass of $\log(M_{*}/{\rm M}_{\odot})=5.77$ have a median S\'ersic index of $n=1.08$ and a median effective radius of $r_{\rm e}=176$ pc, suggesting that typical EMPGs are very compact disk galaxies. We compare the EMPGs with $z\sim 6$ galaxies and local galaxies on the size-mass ($r_{\rm e}$--$M_*$) diagram, and identify that the majority of the EMPGs have a $r_{\rm e}$--$M_*$ relation similar to $z\sim0$ star-forming galaxies rather than $z\sim6$ galaxies. Not every EMPG is a local analog of high-$z$ young galaxies in the $r_{\rm e}$--$M_*$ relation. We also study the PAGs of our galaxies, and find that 23 out of the 27 EMPGs show detectable PAGs within the projected distance of 10 kpc. The PAGs have median values of $n=0.93$, $r_{\rm e}=1.41$ kpc, and $\log(M_{*}/{\rm M}_{\odot})=7.47$ that are similar to those of local dwarf irregulars and ultra-diffuse galaxies. A spectrum of one EMPG-PAG system, so far available, indicates that the PAG is dynamically related to the EMPG with a median velocity difference of $\Delta V=96.1$ km s$^{-1}$. This moderately-large $\Delta V$ cannot be explained by the dynamics of the PAG, but likely by the infall on the PAG. EMPGs may form in infalling gas, and become part of PAG disks undergoing further metal enrichment.

[16]  arXiv:2004.11458 [pdf, ps, other]

Title: The Eulerian space-time correlation of strong Magnetohydrodynamic Turbulence

Authors: Jean C. Perez, Sofiane Bourouaine

Comments: Accepted for publication in the Physical Review Research

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Plasma Physics (physics.plasm-ph); Space Physics (physics.space-ph)

The Eulerian space-time correlation of strong Magnetohydrodynamic (MHD) turbulence in strongly magnetized plasmas is investigated by means of direct numerical simulations of Reduced MHD turbulence and phenomenological modeling. Two new important results follow from the simulations: 1) counter-propagating Alfv\'enic fluctuations at a each scale decorrelate in time at the same rate in both balanced and imbalanced turbulence; and 2) the scaling with wavenumber of the decorrelation rate is consistent with pure hydrodynamic sweeping of small-scale structures by the fluctuating velocity of the energy-containing scales. An explanation of the simulation results is proposed in the context of a recent phenomenological MHD model introduced by Bourouaine and Perez 2019 (BP19) when restricted to the strong turbulence regime. The model predicts that the two-time power spectrum exhibits an universal, self-similar behavior that is solely determined by the probability distribution function of random velocities in the energy-containing range. Understanding the scale-dependent temporal evolution of the space-time turbulence correlation as well as its associated universal properties is essential in the analysis and interpretation of spacecraft observations, such as the recently launched Parker Solar Probe (PSP).

[17]  arXiv:2004.11474 [pdf, other]

Title: Magnetospheric interaction in white dwarf binaries AR Sco and AE Aqr

Authors: Maxim Lyutikov (Purdue University), Maxim Barkov (Purdue University, RIKEN), Matthew Route (Purdue University), Dinshaw Balsara (University of Notre Dame), Peter Garnavich (University of Notre Dame), Colin Littlefield (University of Notre Dame)

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

We develop a model of the white dwarf (WD) - red dwarf (RD) binaries AR Sco and AE Aqr as systems in a transient propeller stage of highly asynchronous intermediate polars. The WDs are relatively weakly magnetized with magnetic field of $\sim 10^6$ G. We explain the salient observed features of the systems due to the magnetospheric interaction of two stars. Currently, the WD's spin-down is determined by the mass loading of the WD's magnetosphere from the RD's at a mild rate of $\dot{M}_{WD} \sim 10^{-11} M_\odot $/yr. Typical loading distance is determined by the ionization of the RD's wind by the WD's UV flux. The WD was previously spun up by a period of high accretion rate from the RD via Roch lobe overflow with $\dot{M} \sim 10^{-9} M_\odot $/yr, acting for as short a period as tens of thousands of years. The non-thermal X-ray and optical synchrotron emitting particles originate in reconnection events in the magnetosphere of the WD due to the interaction with the flow from the RD. In the case of AR Sco, the reconnection events produce signals at the WD's rotation and beat periods - this modulation is due to the changing relative orientation of the companions' magnetic moments and resulting variable reconnection conditions. Radio emission is produced in the magnetosphere of the RD, we hypothesize, in a way that it is physically similar to the Io-induced Jovian decametric radiation.

[18]  arXiv:2004.11507 [pdf, other]

Title: Full-sky Cosmic Microwave Background Foreground Cleaning Using Machine Learning

Authors: Matthew A. Petroff, Graeme E. Addison, Charles L. Bennett, Janet L. Weiland

Comments: 10 pages, 6 figures, submitted to ApJ

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

In order to extract cosmological information from observations of the millimeter and submillimeter sky, foreground components must first be removed to produce an estimate of the cosmic microwave background (CMB). We developed a machine learning approach for doing so for full-sky temperature maps of the millimeter and submillimeter sky. We constructed a Bayesian spherical convolutional neural network architecture to produce a model that captures both spectral and morphological aspects of the foregrounds. Additionally, the model outputs a per-pixel error estimate that incorporates both statistical and model uncertainties. The model was then trained using simulations that incorporated knowledge of these foreground components that was available at the time of the launch of the Planck satellite. On simulated maps, the CMB is recovered with a mean absolute difference of $<4\mu$K over the full sky after masking map pixels with a predicted standard error of $>50\mu$K; the angular power spectrum is also accurately recovered. Once validated with the simulations, this model was applied to Planck temperature observations from its 70GHz through 857GHz channels to produce a foreground-cleaned CMB map at a Healpix map resolution of NSIDE=512. Furthermore, we demonstrate the utility of the technique for evaluating how well different simulations match observations, particularly in regard to the modeling of thermal dust.

[19]  arXiv:2004.11518 [pdf, ps, other]

Title: Revealing new features of the millimetre emission of the circumbinary envelope of Mira Ceti

Authors: D. T. Hoai, P. Tuan-Anh, P.T. Nhung, P. Darriulat, P.N. Diep, N.T. Phuong, T.T. Thai

Comments: 20 pages, 17 figures, accepted for publication in MNRAS

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

We study the morpho-kinematics of the circumbinary envelope of Mira Ceti between $\sim$100 and $\sim$350 au from the stars using ALMA observations of the SiO ($\nu$=0, $J$=5-4) and CO ($\nu$=0, $J$=3-2) emissions with the aim of presenting an accurate and reliable picture of what cannot be ignored when modelling the dynamics at stake. A critical study of the uncertainties attached to imaging is presented. The line emissions are shown to be composed of a few separated fragments. They are described in detail and plausible interpretations of their genesis are discussed. Evidence for a focusing effect of the Mira A wind by Mira B over the past century is presented; it accounts for only a small fraction of the overall observed emission but its accumulation over several orbital periods may have produced an enhancement of CO emission in the orbital plane of Mira B. We identify a South-western outflow and give arguments for the anti-correlation observed between CO and SiO emissions being the result of a recent mass ejection accompanied by a shock wave. We discuss the failure of simple scenarios that have been proposed earlier to explain some of the observed features and comment on the apparent lack of continuity between the present observations and those obtained in the close environment of the stars. Evidence is obtained for the presence of large Doppler velocity components near the line of sight aiming to the star, possibly revealing the presence of important turbulence at $\sim$5 to 10 au away from Mira A.

[20]  arXiv:2004.11522 [pdf, other]

Title: Spectropolarimetric properties of Swift J1818.0$-$1607: a 1.4 s radio magnetar

Authors: Marcus E. Lower, Ryan M. Shannon, Simon Johnston, Matthew Bailes

Comments: Submitted to ApJ Letters. 9 pages, 5 figures and 1 table

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

The soft-gamma repeater Swift J1818.0$-$1607 is only the fifth magnetar found to exhibit pulsed radio emission. Using the Ultra-Wideband Low receiver system of the Parkes radio telescope, we conducted a 3 h observation of Swift J1818.0$-$1607. Folding the data at a rotation period of $P = 1.363$ s, we obtained wideband polarization profiles and flux density measurements covering radio frequencies between 704-4032 MHz. After measuring, and then correcting for the pulsar's rotation measure of $1442.0 \pm 0.2$ rad m$^{-2}$, we find the radio profile is between 80-100 per cent linearly polarized across the wide observing band, with a small amount of depolarization at low frequencies that we ascribe to scatter broadening. We also measure a steep spectral index of $\alpha = -2.26^{+0.02}_{-0.03}$ across our large frequency range, a significant deviation from the flat or inverted spectra often associated with radio-loud magnetars. The steep spectrum and temporal rise in flux density bears some resemblance to the behaviour of the magnetar-like, rotation-powered pulsar PSR J1119$-$6127. This leads us to speculate that Swift J1818.0$-$1607 may represent an additional link between rotation-powered pulsars and magnetars.

[21]  arXiv:2004.11550 [pdf, ps, other]

Title: Statistics and Properties of Emission-Line Regions in the Local Volume Dwarf Galaxies

Authors: Karachentsev I.D., Kaisin S.S

Comments: Accepted in MNRAS

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

We used the $H\alpha$ images from a large sample of nearby late-type dwarf galaxies to investigate properties of their emission structure. The sample consists of three hundred galaxies of the irregular (Irr), Magellanic irregular (Im), blue compact dwarf (BCD), and transition (Tr) types situated within a distance of 11 Mpc. In each galaxy, we indicated: the number of compact HII-regions, the presence of bubble-like or filament-like structures, the presence of a faint diffuse emission, and a sign of the global burst. The larger luminosity of a galaxy, the greater number of compact HII-sources in it. The integral and specific star-formation rates of the dwarf increase steeply with the increase of the number of HII-regions showing the evidence of the epidemic character of star-formation process. The dwarf galaxies with emission-line bubbles, or filaments, or signs of the global star-formation burst have approximately the same hydrogen-mass-to-luminosity ratio as that of the whole sample objects. However, their mean star-formation rate is significantly higher than that of other galaxies in the sample. Emission bubble-like structures are found in the nearby dwarfs with a frequency of 1 case per 4-5 galaxies. Their linear diameters are close to those expected for supernova remnants. The mean specific SFR for the nearby late-type dwarfs is close to the Hubble parameter, $H_0 = -10.14$ dex (yr)$^{-1}$, consistent with the sluggish cosmic star-formation history of galaxies of this kind.

[22]  arXiv:2004.11585 [pdf, other]

Title: Planes of satellites around simulated disc galaxies: I.- Finding high-quality planar configurations from positional information and their comparison to MW/M31 data

Authors: Isabel Santos-Santos, Rosa Dominguez-Tenreiro, Hector Artal, Susana E. Pedrosa, Lucas Bignone, Francisco Martinez-Serrano, M.Angeles Gomez-Flechoso, Patricia B. Tissera, Arturo Serna

Comments: 26 pages, 13 figures, 2 tables. Accepted for publication in ApJ

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

We address the 'plane of satellites problem' by studying planar configurations around two disc galaxies with no late major mergers, formed in zoom-in hydro-simulations. Due to the current lack of good quality kinematic data for M31 satellites, we use only positional information. So far, positional analyses of simulations are unable to find planes as thin and populated as the observed ones. Moreover, they miss systematicity and detail in the plane-searching techniques, as well as in the study of the properties and quality of planes, both in simulations or real data. To fill this gap, i) we extend the 4-galaxy-normal density plot method (Pawlowski et al. 2013) in a way designed to efficiently identify the best quality planes (i.e., thin and populated) without imposing extra constraints on their properties, and ii), we apply it for the first time to simulations. Using zoom-in simulations allows us to mimic MW/M31-like systems regarding the number of satellites involved as well as the galactic disc mass and morphology, in view of possible disc effects. At all timesteps analyzed in both simulations we find satellite planar configurations that are compatible, along given time intervals, with all the spatial characteristics of observed planes identified using the same methodology. However, the fraction of co-orbiting satellites within them is in general low, suggesting time-varying satellite membership. We conclude that high-quality positional planes of satellites are not infrequent in LCDM-formed disc galaxies with a quiet assembly history. Detecting kinematically-coherent, time-persistent planes demands considering the full six-dimensional phase-space information of satellites.

[23]  arXiv:2004.11601 [pdf, other]

Title: Requirements for future CMB satellite missions: photometric and band-pass response calibration

Authors: Tommaso Ghigna, Tomotake Matsumura, Guillaume Patanchon, Hirokazu Ishino, Masashi Hazumi

Comments: 23 pages, 7 figures, 2 tables, Submitted to JCAP

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

Current and future Cosmic Microwave Background (CMB) Radiation experiments are targeting the polarized $B$-mode signal. The small amplitude of this signal makes a successful measurement challenging for current technologies. Therefore, very accurate studies to mitigate and control possible systematic effects are vital to achieve a successful observation. An additional challenge is coming from the presence of polarized Galactic foreground signals that contaminate the CMB signal. When they are combined, the foreground signals dominate the polarized CMB signal at almost every relevant frequency. Future experiments, like the LiteBIRD space-borne mission, aim at measuring the CMB $B$-mode signal with high accuracy to measure the tensor-to-scalar ratio $r$ at the $10^{-3}$ level. We present a method to study the photometric calibration requirement needed to minimize the leakage of polarized Galactic foreground signals into CMB polarization maps for a multi-frequency CMB experiment. We applied this method to the LiteBIRD case, and we found precision requirements for the photometric calibration in the range $\sim10^{-4}-2.5\times10^{-3}$ depending on the frequency band. Under the assumption that the detectors are uncorrelated, we found requirements per detector in the range $\sim0.18\times10^{-2}-2.0\times10^{-2}$. Finally, we relate the calibration requirements to the band-pass resolution to define constraints for a few representative band-pass responses: $\Delta\nu\sim0.2-2$ GHz.

[24]  arXiv:2004.11620 [pdf, other]

Title: Barred galaxies in the Illustris-1 and TNG100 simulations

Authors: Ze-Bang Zhou, Weishan Zhu, Yang Wang, Long-Long Feng

Comments: 22 pages, 20 figures. Accepted for publication in The Astrophysical Journal

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

We carry out a comparison study on the bar structure in the Illustris-1 and TNG100 simulations. At $z=0$, 8.9\% of 1232 disc galaxies with stellar mass $>10^{10.5}M_{\odot}$ in Illustris-1 are barred, while the numbers are 55\% of 1269 in TNG100. The bar fraction as a function of stellar mass in TNG100 agrees well with the survey $S^4G$. The median redshift of bar formation are $\sim 0.4-0.5$ and $\sim 0.25$ in TNG100 and Illustris-1 respectively. Bar fraction generally increases with stellar mass and decreases with gas fraction in both simulations. Barred galaxy had higher gas fraction at high redshift tend to form bar later. When the bars were formed, the disc gas fractions were mostly lower than 0.4. The much higher bar fraction in TNG100 probably have benefit from much lower gas fraction in massive disc galaxies since $z\sim3$, which may result from the combination of more effective stellar and AGN feedback. The latter may be the primary factor at $z<2$. Meanwhile, in both simulations, barred galaxies have higher star formation rate before bar formation, and stronger AGN feedback all the time than unbarred galaxies. The properties of dark matter halos hosting massive disc galaxies are similar between two simulations, and should have minor effect on the different bar frequency. For individual galaxies under similar halo environment cross two simulations, different baryonic physics can lead to striking discrepancy on morphology. The morphology of individual galaxies is subject to combined effects of environment and internal baryonic physics, and is often not predictable.

[25]  arXiv:2004.11643 [pdf, other]

Title: Cosmology with gravitationally lensed repeating Fast Radio Bursts

Authors: O. Wucknitz (1), L.G. Spitler (1), U.-L. Pen (2,3,4,5,1) ((1) Max-Planck-Institute for Radio Astronomy, (2) CITA, (3) Dunlap Institute, (4) CIFAR, (5) Perimeter Institute)

Comments: Submitted to A&A, 14 pages

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

High-precision cosmological probes have revealed a small but significant tension between the parameters measured with different techniques, one of which is based on time delays in gravitational lenses. We discuss a new way of using time delays for cosmology, taking advantage of the extreme precision expected for lensed Fast Radio Bursts, short flashes of radio emission originating at cosmological distances. With coherent methods the achievable precision is sufficient to even measure how time delays change over the months and years, which can also be interpreted as differential redshifts between the images. It turns out that uncertainties arising from the unknown mass distribution of gravitational lenses can be eliminated by combining time delays with their time derivatives. Other effects, most importantly relative proper motion, can be measured accurately and separated from the cosmological effects. With a mock sample of simulated lenses we show that strong constraints on cosmological parameters are potentially possible. Finally the lensed images can be used as galactic interferometer to resolve structures and motions of the burst sources with insanely high resolution and help revealing their currently unknown physical nature.

[26]  arXiv:2004.11669 [pdf, other]

Title: Why the mean mass of primordial black hole distribution is close to 10$M_{\odot}$

Authors: Alexander Dolghov (ITEP Moscow, NGU Novosibirsk), Konstantin Postnov (Sternberg Astronomical Institute, Moscow)

Comments: 4 pages, LaTeX, no figures

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

It is shown that a mechanism of PBH formation with log-normal mass spectrum leads to the central mass of PBH distribution close to ten solar masses independently of the model details. This result is in good agreement with observations.

[27]  arXiv:2004.11688 [pdf, ps, other]

Title: Rotation Curve of the Milky Way and the Dark Matter Density

Authors: Yoshiaki Sofue

Comments: Invited review for Galaxies in special issue on "Debate on the Physics of Galactic Rotation and the Existence of Dark Matter", 28 pages, 4 figures, 8 tables

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

We review the~current status of the~study of rotation curve (RC) of the~Milky Way, and~present a~unified RC from the~Galactic Center to the galacto-centric distance of about 100 kpc. The~RC is used to directly calculate the~distribution of the~surface mass density (SMD). We then propose a~method to derive the~distribution of dark matter (DM) density in the~in the~Milky Way using the~SMD distribution. The~best-fit dark halo profile yielded a local DM density of $\rho_\odot = 0.36\pm 0.02$ GeV/cc. We also review the~estimations of the~local DM density in the~last decade, and~show that the~value is converging to a~value at $\rho_\odot=0.39\pm 0.09$ GeV/cc.

[28]  arXiv:2004.11740 [pdf, other]

Title: Exploiting orbital constraints from optical data to detect binary gamma-ray pulsars

Authors: L. Nieder (1 and 2), B. Allen (1 and 3 and 2), C. J. Clark (4), H. J. Pletsch (1) ((1) Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), (2) Leibniz Universität Hannover, (3) Department of Physics, University of Wisconsin-Milwaukee, (4) Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy)

Comments: 32 pages, 7 figures

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

It is difficult to discover pulsars via their gamma-ray emission because current instruments typically detect fewer than one photon per million rotations. This creates a significant computing challenge for isolated pulsars, where the typical parameter search space spans wide ranges in four dimensions. It is even more demanding when the pulsar is in a binary system, where the orbital motion introduces several additional unknown parameters. Building on earlier work by Pletsch & Clark (arXiv:1408.6962), we present optimal methods for such searches. These can also incorporate external constraints on the parameter space to be searched, for example from optical observations of a presumed binary companion. The solution has two parts. The first is the construction of optimal search grids in parameter space via a parameter-space metric, for initial semi-coherent searches and subsequent fully-coherent follow-ups. The second is a method to demodulate and detect the periodic pulsations. These methods have different sensitivity properties than traditional radio searches for binary pulsars, and might unveil new populations of pulsars.

[29]  arXiv:2004.11747 [pdf, other]

Title: On the tidal tails of Milky Way globular clusters

Authors: Andrés E. Piatti, Julio A. Carballo-Bello

Comments: 5 pages, 3 figures. Accepted for publication in Astronomy & Astrophysics Letters

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

We report on the search for overall kinematical or structural conditions that have allowed some Milky Way globular clusters to presently develop tidal tails. For this purpose, we build a comprehensive catalogue of globular clusters with studies focused on their outermost regions and classified them in three categories: those with observed tidal tails, those with extra-tidal features different from tidal tails and those without any signature of extended stellar density profiles. When exploring different kinematical and structural parameter spaces, we found that globular clusters - irrespective from the presence of tidal tails, or any other kind of extra-tidal features or the absence of them - behave similarly. In general, globular clusters whose orbits are relatively more eccentric and very inclined respect to the Milky Way plane have undergone a larger amount of mass-loss by tidal disruption. The latter has also accelerated the internal dynamics toward a comparatively more advanced stage of evolution. These outcomes show that it is not straightforward to find any particular set of parameter space and dynamical conditions that can definitely predict tidal tails along globular clusters in the Milky Way.

[30]  arXiv:2004.11758 [pdf, other]

Title: Chemical desorption versus energy dissipation: insights from ab-initio molecular dynamics of HCO formation

Authors: Stefano Pantaleone, Joan Enrique-Romero, Cecilia Ceccarelli, Piero Ugliengo, Nadia Balucani, Albert Rimola

Comments: Appendix not included. Submitted to ApJ

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

Molecular clouds are the cold regions of the Milky Way where stars form. They are enriched by rather complex molecules. Many of these molecules are believed to be synthesized on the icy surfaces of the interstellar submicron-sized dust grains that permeate the Galaxy. At 10 K thermal desorption is ineffcient and, therefore, why these molecules are found in the cold gas has tantalized astronomers for years. The assumption of the current models, called chemical desorption, is that the molecule formation energy released by the chemical reaction at the grain surface is partially absorbed by the grain and the remaining one causes the ejection of the newly formed molecule into the gas. Here we report an accurate ab-initio molecular dynamics simulations aimed to study the fate of the energy released by the first reaction of the H addition chain on CO, CO + H $\rightarrow$ HCO, occurring on a crystalline ice surface model. We show that about 90% of the HCO formation energy is injected towards the ice in the first picosecond, leaving HCO with an energy content (10-15 kJ mol$^{-1}$) more than a factor two lower than its adsorption energy (30 kJ mol$^{-1}$). As a result, in agreement with laboratory experiments, we conclude that chemical desorption is ineffcient for this specific system, namely H + CO on crystalline ice. We suspect this behavior to be quite general when dealing with hydrogen bonds, which are responsible of both the cohesive energy of the ice mantle and the interaction with adsorbates, as the HCO radical, even though ad hoc simulations are needed to draw specific conclusions on other systems.

[31]  arXiv:2004.11764 [pdf, ps, other]

Title: Possibilities of Using Middle-Band Filters to Search for Polar Candidates

Authors: M.M. Gabdeev, T.A. Fatkhullin, N.V. Borisov

Comments: 10 pages, 5 figures, 2 tables

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

We present a method for searching for polar candidates using mid-band filters. One of the spectral singularities of polars is the $HeII \lambda4686$\AA~ strong emission line. We selected the Edmund Optics filters with central wavelengths of 470, 540, and 656 nm and a transmission bandwidth of 10 nm. These filters cover the regions of the $HeII \lambda4686$\AA~ line, continuum, and the $H_\alpha$ line respectively. We constructed a color diagram based on the available spectra of polars and objects with a zero redshift from the SDSS archive. We show that most polars make a group with unique color indices. In practice, the method is implemented in SAO RAS at the Zeiss-1000 telescope with a new multi-mode photometer-polarimeter (MMPP). Approbation of the method with the known polars allowed us to develop two criteria to select candidates with an efficiency of up to 75\%.

[32]  arXiv:2004.11775 [pdf, other]

Title: Statistical Study of GOES X-ray Quasi-Periodic Pulsations in Solar Flares

Authors: Laura A. Hayes, Andrew R. Inglis, Steven Christe, Brian Dennis, Peter T. Gallagher

Comments: 17 pages, 13 figures, accepted in The Astrophysical Journal

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

Small amplitude quasi-periodic pulsations (QPPs) detected in soft X-ray emission are commonplace in many flares. To date, the underpinning processes resulting in the QPPs are unknown. In this paper, we attempt to constrain the prevalence of \textit{stationary} QPPs in the largest statistical study to date, including a study of the relationship of QPP periods to the properties of the flaring active region, flare ribbons, and CME affiliation. We build upon the work of \cite{inglis2016} and use a model comparison test to search for significant power in the Fourier spectra of lightcurves of the GOES 1--8~\AA\ channel. We analyze all X-, M- and C- class flares of the past solar cycle, a total of 5519 flares, and search for periodicity in the 6-300~s timescale range. Approximately 46\% of X-class, 29\% of M-class and 7\% of C-class flares show evidence of stationary QPPs, with periods that follow a log-normal distribution peaked at 20~s. The QPP periods were found to be independent of flare magnitude, however a positive correlation was found between QPP period and flare duration. No dependence of the QPP periods to the global active region properties was identified. A positive correlation was found between QPPs and ribbon properties including unsigned magnetic flux, ribbon area and ribbon separation distance. We found that both flares with and without an associated CME can host QPPs. Furthermore, we demonstrate that for X- and M- class flares, decay phase QPPs have statistically longer periods than impulsive phase QPPs.

[33]  arXiv:2004.11786 [pdf, other]

Title: Correlations and lags between X-ray and radio emission of Cyg X-1

Authors: Jimmy N. S. Shapopi, Andrzej A. Zdziarski

Comments: 6 pages, 2 figures, Proceeding from the 7th Annual Conference on High Energy Astrophysics in Southern Africa

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

Cygnus X-1 is a Galactic black-hole binary and a microquasar. Its X-ray emission originates most likely in the accretion flow, while the radio emission is from a magnetized jet. We study long-term cross-correlations between its X-ray and radio fluxes, searching for lags of the peak of the correlation. We use soft X-ray data from the All Sky Monitor on board of Rossi X-ray Timing Explorer, hard X-ray data from the Burst Alert Telescope on board of Neil Gehrels Swift, and 15 GHz radio monitoring data from the Ryle and AMI telescopes, which light curves cover all of the spectral states of Cyg X-1. Previous studies of radio/X-ray correlations in black-hole binaries concentrated on the soft X-ray/radio correlation in the hard spectral state. In contrast, our strongest correlation is between the hard X-rays and radio in the entire data at a $\lesssim 1$-day lag. This indicates the jet formation from a hard X-ray emitting corona/hot accretion flow through all states of Cyg X-1. We also find evidence for a long lag of the radio with respect to the soft X-rays in the soft state. This indicates long-term advection of the magnetic field through the accretion disc from its high-mass donor, which is similar to the case of another microquasar with a high-mass donor, Cyg X-3.

[34]  arXiv:2004.11808 [pdf, ps, other]

Title: A Barometric Exponential Model of the Atmosphere's Refractive Index: Zenith Angles and Second Order Aberration in the Entrance Pupil

Authors: Richard J. Mathar

Comments: 15 pages, 9 figures, C++ source in anc directory

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

This report models the refractive index above a telescope site by a homogeneous atmosphere with exponential decay of the refractive index (susceptibility) as a function of altitude. The air is represented as a spherical hull with a symmetry center at the Earth center. We compute (i) the differential zenith angle -- the difference between the actual zenith angle at arrival of rays at the telescope and a hypothetical zenith angle without the atmosphere -- and (ii) the optical path length distribution of rays at arrival in the entrance pupil as a function of the distance to the pupil center. The key technique of the semi-numerical mathematics in this work is to expand some integrals -- that depend on the refractive index profile along the curved path of each ray from some virtual plane in the direction of the star up to the entrance pupil -- in power series of small parameters.

[35]  arXiv:2004.11821 [pdf, other]

Title: Galactic population of black holes in detached binaries with low-mass stripped helium stars: the case of LB-1 (LS~V+22~25)

Authors: L.R. Yungelson, A.G. Kuranov, K.A. Postnov, D.A. Kolesnikov

Comments: 5 pp., 6 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society Letters

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

We model the Galactic population of detached binaries that harbor black holes with (0.5-1.7) solar mass companions -- the remnants of case B mass-exchange that rapidly cross Hertzsprung gap after the termination of the Roche-lobe overflow or as He-shell burning stars. Several such binaries can be currently present in the Galaxy. The range of black hole masses in them is about 4 to 10 solar ones, the orbital periods are tens to hundreds day. The unique BH-binary LB-1 fits well into this extremely rare class of double stars.

[36]  arXiv:2004.11866 [pdf, other]

Title: Making GW190412: isolated formation of a 30+10 Msun binary black-hole merger

Authors: A.Olejak, K.Belczynski, D.E. Holz, J.-P. Lasota, T.Bulik, M.C. Miller

Comments: 5 pages, comments welcome

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

The LIGO/Virgo collaboration has reported the detection of GW190412, a black hole-black hole (BH-BH) merger with the most unequal masses to date: m_1=24.4--34.7 Msun and m_2=7.4--10.1 Msun, corresponding to a mass ratio of q=0.21--0.41 (90 per cent probability range). Additionally, GW190412's effective spin was estimated to be X_eff=0.14--0.34, with the spin of the primary BH in the range a_spin=0.17--0.59. Based on this and prior detections, >10 per cent of BH-BH mergers have q<0.4. Major BH-BH formation channels (i.e., dynamics in dense stellar systems, classical isolated binary evolution, or chemically homogeneous evolution) tend to produce BH-BH mergers with comparable masses (typically with q>0.5). Here we test whether the classical isolated binary evolution channel can produce mergers resembling GW190412. We show that our standard binary evolution scenario, with the typical assumptions on input physics we have used in the past, produces such mergers. We provide an explicit example of an unequal mass BH-BH merger, which forms at low metallicity (Z=0.002) from two massive stars (77 and 35 Msun) and results in a BH-BH merger with m_1=27.0 Msun, m_2=9.9 Msun (q=0.37), with primary black hole spin a_spin=0.19 and an effective spin parameter X_eff=0.335. For this particular model of the input physics the overall BH-BH merger rate density in the local Universe (z=0) is: 73.5 Gpc^-3 yr^-1, while for systems with q<0.21, 0.28, 0.41, and 0.59 the rate density is: 0.01, 0.12, 6.8, and 22.2 Gpc^-3 yr^-1, respectively. The results from our standard model are consistent with the masses and spins of the black holes in GW190412, as well as with the LIGO/Virgo estimate of the fraction of unequal-mass BH-BH mergers.

[37]  arXiv:2004.11873 [pdf, other]

Title: State-of-the-art AGN SEDs for Photoionization Models: BLR Predictions Confront the Observations

Authors: Gary Ferland, Chris Done, Chichuan Jin, Hermine Landt, Martin Ward

Comments: 6 pages, 2 figures. Accepted for publication in MNRAS

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

The great power offered by photoionization models of Active Galactic Nuclei (AGN) emission-line regions has long been mitigated by the fact that very little is known about the spectral energy distribution (SED) between the Lyman limit, where intervening absorption becomes a problem, and 0.3 keV, where soft x-ray observations become possible. The emission lines themselves can, to some degree, be used to probe the SED, but only in the broadest terms. This paper employs a new generation of theoretical SEDs which are internally self-consistent, energy-conserving, and tested against observations, to infer properties of the emission-line regions. The SEDs are given as a function of the Eddington ratio, allowing emission-line correlations to be investigated on a fundamental basis. We apply the simplest possible tests, based on the foundations of photoionization theory, to investigate the implications for the geometry of the emission-line region. The SEDs become more far-ultraviolet bright as the Eddington ratio increases, so the equivalent widths of recombination lines should also become larger, an effect which we quantify. The observed lack of correlation between Eddington ratio and equivalent width shows that the cloud covering factor must decrease as Eddington ratio increases. This would be consistent with recent models proposing that the broad-line region is a failed dusty wind off the accretion disc.

[38]  arXiv:2004.11881 [pdf, other]

Title: Growth of structures and spherical collapse in the Galileon Ghost Condensate model

Authors: Noemi Frusciante, Francesco Pace

Comments: 14 pages, 10 figures, 2 tables. Comments welcome

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

We present a detailed study of the collapse of a spherical matter overdensity and the non-linear growth of large scale structures in the Galileon ghost condensate (GGC) model. This model is an extension of the cubic covariant Galileon (G3) which includes a field derivative of type $(\nabla_\mu\phi\nabla^\mu\phi)^2$ in the Lagrangian. We find that the cubic term activates the modifications in the main physical quantities and the additional term has an extended impact in the evolution of the latter. The GGC model shows largely mitigated effects in the linearised critical density contrast, non-linear effective gravitational coupling and the virial overdensity with respect to G3 but still preserves peculiar features with respect to the standard $\Lambda$CDM cosmological model, e.g., both the linear critical density contrast and the virial overdensity are larger than the ones in $\Lambda$CDM. The results of the spherical collapse model are then used to predict the evolution of the halo mass function, non-linear matter and lensing power spectra. While at low masses the GGC model presents about 10% fewer objects with respect to $\Lambda$CDM, at higher masses for $z>0$ it predicts 10% ($z=0.5$)-20% ($z=1$) more objects per comoving volume. Using a phenomenological approach to include the screening effect in the matter power spectrum, we show that the difference induced by the modifications of gravity are strongly dependent on the screening scale and that differences can be up to 60% with respect to $\Lambda$CDM. These differences translate to the lensing power spectrum where qualitatively the largest differences with respect to the standard cosmological model are for $\ell<10^3$. Depending on the screening scale, they can reach 60% on larger angular scales and then decrease for growing $\ell$. The results are obtained for the best fit parameters from cosmological data for each model.

[39]  arXiv:2004.11884 [pdf, other]

Title: Multi-wavelength observations of PSRJ 2032+4127 during the 2017 periastron passage

Authors: Maria Chernyakova, Denys Malyshev, Pere Blay, Brian van Soelen, Sergey Tsygankov

Comments: accepted to MNRAS

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

PSRJ 2032+4127 is only the second known gamma-ray binary where it is confirmed that a young radio pulsar is in orbit around a Be-star. The interaction of the pulsar wind with the mass outflow from the companion leads to broad band emission from radio up to TeV energies. In the current paper we present results of optical monitoring of the 2017 periastron passage with the Nordic Optical Telescope. These observations are complemented by X-ray (Swift/XRT, NuSTAR) and GeV (Fermi/LAT) monitoring. Joint analysis of the evolution of the parameters of the Halpha line and the broadband (X-ray to TeV) spectral shape allows us to propose a model linking the observed emission to the interaction of the pulsar and Be-star winds under the assumption of the inclined disc geometry. Our model allows the observed flux and spectral evolution of the system to be explained in a self-consistent way.

Cross-lists for Mon, 27 Apr 20

[40]  arXiv:2004.11392 (cross-list from hep-ph) [pdf, ps, other]

Title: Gravitational wave background from Standard Model physics: Complete leading order

Authors: J. Ghiglieri, G. Jackson, M. Laine, Y. Zhu

Comments: 33 pages

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

We compute the production rate of the energy density carried by gravitational waves emitted by a Standard Model plasma in thermal equilibrium, consistently to leading order in coupling constants for momenta $k\sim \pi T$. Summing up the contributions from the full history of the universe, the highest temperature of the radiation epoch can be constrained by the so-called $N_{\rm eff}$ parameter. The current theoretical uncertainty $\Delta N_{\rm eff} \le 10^{-3}$ corresponds to $T_{\rm max} \le 2\times 10^{17}$ GeV. In the course of the computation, we show how a subpart of the production rate can be determined with the help of standard packages, even if subsequently an IR subtraction and thermal resummation need to be implemented.

[41]  arXiv:2004.11542 (cross-list from gr-qc) [pdf, other]

Title: Reflection features in the X-ray spectrum of Fairall 9 and implications for tests of general relativity

Authors: Honghui Liu, Haiyang Wang, Askar B. Abdikamalov, Dimitry Ayzenberg, Cosimo Bambi

Comments: 10 pages, 7 figures

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

X-ray reflection spectroscopy is potentially a powerful tool to probe the spacetime geometry around astrophysical black holes and test general relativity in the strong field regime. However, precision tests of general relativity are only possible if we employ the correct astrophysical model and we can limit the systematic uncertainties. It is thus crucial to select the sources and the observations most suitable for these tests. In this work, we analyze simultaneous observations of XMM-Newton and NuSTAR of the supermassive black hole in Fairall 9. This source has a number of properties that make it a promising candidate for tests of general relativity using X-ray reflection spectroscopy. Nevertheless, we find that with the available data there is not a unique interpretation of the spectrum of Fairall 9, which prevents, for the moment, to use this source for robust tests of general relativity. This issue may be solved by future X-ray missions with a higher energy resolution near the iron line.

[42]  arXiv:2004.11557 (cross-list from gr-qc) [pdf, ps, other]

Title: Constraining theories of gravity by fundamental plane of elliptical galaxies

Authors: Salvatore Capozziello, Vesna Borka Jovanović, Duško Borka, Predrag Jovanović

Comments: 13 pages, 7 figures, to be published in Phys. Dark. Univ. (2020)

Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics of Galaxies (astro-ph.GA)

We show that fundamental plane of elliptical galaxies can be used to obtain observational constraints on metric theories of gravity. Being it connected to global properties of ellipticals, it can fix parameters of modified gravity. Specifically, we use fundamental plane to constrain modified theories of gravity with Yukawa-like corrections which commonly emerge in the post-Newtonian limit. After giving examples on how these corrections are derived, we first analyze the velocity distribution of elliptical galaxies comparing theoretical results of modified gravity with Yukawa-like corrections with astronomical data. According to these results, it is possible to constrain the parameters of the corrections discriminating among classes of models compatible with astronomical observations. We conclude that fundamental plane can be used as a standard tool to probe different theories of gravity in the weak field limit.

[43]  arXiv:2004.11560 (cross-list from hep-ph) [pdf, ps, other]

Title: Axion Model with Intermediate Scale Fermionic Dark Matter

Authors: George Lazarides, Qaisar Shafi

Comments: 17 pages, 5 figures included

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

We investigate a non-supersymmetric $SO(10)\times U(1)_{\rm PQ}$ axion model in which the spontaneous breaking of $U(1)_{\rm PQ}$ occurs after inflation, and the axion domain wall problem is resolved by employing the Lazarides-Shafi mechanism. This requires the introduction of two fermion 10-plets, such that the surviving discrete symmetry from the explicit $U(1)_{\rm PQ}$ breaking by QCD instantons is reduced from $Z_{12}$ to $Z_4$, where $Z_4$ is precisely the center of $SO(10)$. An unbroken $Z_2$ subgroup of $Z_4$ yields intermediate scale topologically stable strings, as well as a stable electroweak doublet non-thermal dark matter candidate from the fermion 10-plets with mass comparable to or somewhat smaller than the axion decay constant $f_{\rm a}$. We present an explicit realization with inflation taken into account and which also incorporates non-thermal leptogenesis. The fermion dark matter mass lies in the $3\times 10^{8}-10^{10}~{\rm GeV}$ range and its contribution to the relic dark matter abundance can be comparable to that from the axion.

[44]  arXiv:2004.11845 (cross-list from gr-qc) [pdf, ps, other]

Title: An Examination of Geometrical and Potential Time Delays in Gravitational Lensing

Authors: Oleg Yu. Tsupko, Gennady S. Bisnovatyi-Kogan, Adam Rogers, Xinzhong Er

Comments: 13 pages, 5 figures

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

In this paper we investigate the relation between the potential, and the geometrical time delays in the gravitational lensing. In the original paper of Shapiro (1964), it is stated that there is a time delay in the radar signals between Earth and Venus, passing near a massive object (the Sun), relative to a case of the absence of such mass. The reason is connected with the influence of the gravity on the speed of a light rays in a gravitational potential. The contribution from the change of the path length, which happens to be of a second order, is considered as negligible. Nevertheless, in the gravitational lens theory the geometrical delay, related to the change of path length, is routinely taken into account along with the potential term. Inspired by this apparent discrepancy, in this work we address the contribution of the geometric part of the time delay in different situations. We introduce a unified treatment with two limiting regimes of lensing. One of them corresponds to the time delay experiments near the Sun where geometrical delay is shown to be negligible. The second corresponds to the typical gravitational lens scenario with multiple imaging where the geometrical delay is shown to be significant. In particular, it is shown that the geometrical delay is non-negligible in the case of good alignment between source, lens and observer, because in such a case it becomes a first order quantity.

[45]  arXiv:2004.11895 (cross-list from gr-qc) [pdf, other]

Title: Detecting scalar fields with Extreme Mass Ratio Insirals

Authors: Andrea Maselli, Nicola Franchini, Leonardo Gualtieri, Thomas P. Sotiriou

Comments: 7 pages, 2 Figures

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

We study Extreme Mass Ratio Inspirals (EMRIs), during which a small body spirals into a supermassive black hole, in gravity theories with additional scalar fields. We first argue that no-hair theorems and the properties of known theories that manage to circumvent them introduce a drastic simplification to the problem: the effects of the scalar on supermassive black holes, if any, are mostly negligible for EMRIs in vast classes of theories. We then exploit this simplification to model the inspiral perturbatively and we demonstrate that the scalar charge of the small body leaves a significant imprint on gravitational wave emission. Although much higher precision is needed for waveform modelling, our results strongly suggest that this imprint is observable with LISA, rendering EMRIs a promising probe of scalar fields.

Replacements for Mon, 27 Apr 20

[46]  arXiv:1409.3775 (replaced) [pdf, ps, other]

Title: Dark Energy and Mass Generation

Authors: Marco Frasca

Comments: 3 pages, no figure. Fixed a sign and some misprints

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

[47]  arXiv:1901.01410 (replaced) [pdf, other]

Title: Origin of the Heaviest Elements: the Rapid Neutron-Capture Process

Authors: John J. Cowan, Christopher Sneden, James E. Lawler, Ani Aprahamian, Michael Wiescher, Karlheinz Langanke, Gabriel Martínez-Pinedo, Friedrich-Karl Thielemann

Comments: 95 pages, 42 figures, 2 tables, submitted to Reviews of Modern Physics

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

[48]  arXiv:1904.07214 (replaced) [pdf, other]

Title: New binary black hole mergers in the second observing run of Advanced LIGO and Advanced Virgo

Authors: Tejaswi Venumadhav, Barak Zackay, Javier Roulet, Liang Dai, Matias Zaldarriaga

Comments: Accepted to PRD

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

[49]  arXiv:1910.02962 (replaced) [pdf, other]

Title: 3D Distribution Map of HI Gas and Galaxies Around an Enormous Ly$α$ Nebula and Three QSOs at $z=2.3$ Revealed by the HI Tomographic Mapping Technique

Authors: Shiro Mukae, Masami Ouchi, Zheng Cai, Khee-Gan Lee, J. Xavier Prochaska, Sebastiano Cantalupo, Zheng Zheng, Kentaro Nagamine, Nao Suzuki, John D. Silverman, Toru Misawa, Akio K. Inoue, Joseph F. Hennawi, Yuichi Matsuda, Ken Mawatari, Yuma Sugahara, Takashi Kojima, Yoshiaki Ono, Takatoshi Shibuya, Yuichi Harikane, Seiji Fujimoto, Yi-Kuan Chiang, Haibin Zhang, Ryota Kakuma

Comments: 15 pages, 9 figures. Minor revisions

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

[50]  arXiv:1910.03550 (replaced) [pdf, ps, other]

Title: Gravitational Lensing of the Cosmic Neutrino Background

Authors: Joshua Yao-Yu Lin, Gilbert Holder

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

[51]  arXiv:1910.03636 (replaced) [pdf, other]

Title: Reconstructing Functions and Estimating Parameters with Artificial Neural Networks: A Test with the Hubble Parameter and SNe Ia

Authors: Guo-Jian Wang, Xiao-Jiao Ma, Si-Yao Li, Jun-Qing Xia

Comments: 15 pages, 16 figures, and 1 table, matches published version. The code repository is available at this https URL

Journal-ref: Astrophys.J.Suppl. 246 (2020) no.1, 13

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Methods for Astrophysics (astro-ph.IM); Data Analysis, Statistics and Probability (physics.data-an)

[52]  arXiv:1910.05015 (replaced) [pdf, other]

Title: A mean density of $112\, M_{\odot}\,\rm pc^{-3}$ for Central Molecular Zone clumps -- Evidences for shear-enabled pressure equilibrium in the Galactic Center

Authors: Guang-Xing Li, Chuan-Peng Zhang

Comments: Accepted for publication by the ApJ

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

[53]  arXiv:1910.07397 (replaced) [pdf, other]

Title: Searching for primordial black holes with stochastic gravitational-wave background in the space-based detector frequency band

Authors: Yi-Fan Wang, Qing-Guo Huang, Tjonnie G.F. Li, Shihong Liao

Comments: 10 pages, 7 figures. Published version in Physical Review D

Journal-ref: Phys. Rev. D 101, 063019 (2020)

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

[54]  arXiv:1910.07554 (replaced) [pdf, ps, other]

Title: Pseudosmooth Tribrid Inflation in $SU(5)$

Authors: Muhammad Atif Masoud, Mansoor Ur Rehman, Qaisar Shafi

Comments: 18 pages, 8 figures, JCAP published version

Journal-ref: JCAP 04 (2020) 041

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

[55]  arXiv:1911.03499 (replaced) [pdf, other]

Title: The Impact of Scatter in the Galaxy UV Luminosity to Halo Mass Relation on Ly$α$ Visibility During the Epoch of Reionization

Authors: Lily R. Whitler, Charlotte A. Mason, Keven Ren, Mark Dijkstra, Andrei Mesinger, Laura Pentericci, Michele Trenti, Tommaso Treu

Comments: 14 pages, 7 figures, accepted for publication in MNRAS

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

[56]  arXiv:1911.04182 (replaced) [pdf, other]

Title: Corrections to the gravitational wave phasing

Authors: Shaoqi Hou, Xi-Long Fan, Zong-Hong Zhu

Comments: 12 pages, 2 figures. Match the published version

Journal-ref: Phys. Rev. D 101, 084052 (2020)

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

[57]  arXiv:1911.13281 (replaced) [pdf, other]

Title: Compact Dark Matter Objects via $N$ Dark Sectors

Authors: Gia Dvali, Emmanouil Koutsangelas, Florian Kuhnel

Comments: 13 pages, 2 figures; v2: minor modifications to match published version

Journal-ref: Phys. Rev. D 101, 083533 (2020)

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

[58]  arXiv:1912.04314 (replaced) [pdf, other]

Title: The role of galaxies and AGN in reionising the IGM -- III : IGM-galaxy cross-correlations at z~6 from 8 quasar fields with DEIMOS and MUSE

Authors: Romain A. Meyer, Koki Kakiichi, Sarah E. I. Bosman, Richard S. Ellis, Nicolas Laporte, Brant E. Robertson, Emma V. Ryan-Weber, Ken Mawatari, Adi Zitrin

Comments: Accepted for publication in MNRAS. 17 pages, 18 figures, 3 tables + appendices. Key results: Figs. 6,13,14. Updated version matches the published one ('online' Appendices are directly in the arXiv pdf). Conclusions unchanged from earlier preprint

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

[59]  arXiv:1912.11647 (replaced) [pdf, other]

Title: The impact of filamentary accretion of subhaloes on the shape and orientation of haloes

Authors: Yu Morinaga, Tomoaki Ishiyama

Comments: Accepted for publication in MNRAS, 9 pages, 6 figures, 1 table

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

[60]  arXiv:1912.12499 (replaced) [pdf, other]

Title: Non-linear damping of superimposed primordial oscillations on the matter power spectrum in galaxy surveys

Authors: Mario Ballardini, Riccardo Murgia, Marco Baldi, Fabio Finelli, Matteo Viel

Comments: 23 pages, 10 figures, 1 table. Version accepted by JCAP

Journal-ref: JCAP 04 (2020) 030

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

[61]  arXiv:2001.05909 (replaced) [pdf, other]

Title: Primordial black holes and secondary gravitational waves from k/G inflation

Authors: Jiong Lin, Qing Gao, Yungui Gong, Yizhou Lu, Chao Zhang, Fengge Zhang

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

[62]  arXiv:2001.10547 (replaced) [pdf, other]

Title: Outflows and extended [CII] halos in high redshift galaxies

Authors: Elia Pizzati, Andrea Ferrara, Andrea Pallottini, Simona Gallerani, Livia Vallini, Davide Decataldo, Seiji Fujimoto

Comments: 13 pages, 7 figures; accepted for publication in MNRAS

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

[63]  arXiv:2002.03890 (replaced) [pdf, other]

Title: Discrete Chi-square Method for Detecting Many Signals

Authors: Lauri Jetsu

Comments: 20 pages, 14 figures, 8 tables

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Methodology (stat.ME)

[64]  arXiv:2003.01738 (replaced) [pdf, other]

Title: Physical models of streaming instabilities in protoplanetary disks

Authors: Jonathan Squire, Philip F. Hopkins

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

[65]  arXiv:2003.02374 (replaced) [pdf, other]

Title: Probing beyond-Kerr spacetimes with inspiral-ringdown corrections to gravitational waves

Authors: Zack Carson, Kent Yagi

Comments: 18 pages, 4 figures; Updated to match published version

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

[66]  arXiv:2003.09900 (replaced) [pdf, other]

Title: Cosmic ray feedback from supernovae in dwarf galaxies

Authors: Gohar Dashyan, Yohan Dubois

Comments: 19 pages, 15 figures, A&A accepted

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

[67]  arXiv:2003.11101 (replaced) [pdf]

Title: First Observation of a Type II Solar Radio Burst Transitioning Between a Stationary and Drifting State

Authors: Nicolina Chrysaphi, Hamish A. S. Reid, Eduard P. Kontar

Comments: Published in ApJ, 11 pages, 10 figures

Journal-ref: ApJ, 893, 115 (2020)

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Plasma Physics (physics.plasm-ph); Space Physics (physics.space-ph)

[68]  arXiv:2003.12512 (replaced) [src]

Title: SKA1-LOW Antenna Design Document

Authors: Eloy de Lera Acedo, Hardie Pienaar

Comments: Report currently under review by the SKA Office

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

[69]  arXiv:2003.14314 (replaced) [pdf, other]

Title: NGTS J214358.5-380102 -- NGTS discovery of the most eccentric known M-Dwarf binary system

Authors: Jack S. Acton, Michael R. Goad, Liam Raynard, Sarah L. Casewell, James A.G. Jackman, Richard D. Alexander, David R. Anderson, Daniel Bayliss, Edward M. Bryant, Matthew R. Burleigh, Claudia Belardi, Benjamin F. Cooke, Phillip Eigmüller, Samuel Gill, James S. Jenkins, Monika Lendl, Tom Louden, James McCormac, Maximiliano Moyano, Louise D. Nielsen, Rosanna H. Tilbrook, Stéphane Udry, Christopher A. Watson, Richard G. West, Peter J. Wheatley, Jose I. Vines

Comments: Accepted for Publication in MNRAS

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

[70]  arXiv:2004.00400 (replaced) [pdf, other]

Title: A radiative transfer model for the spiral galaxy M33

Authors: Jordan J. Thirlwall, Cristina C. Popescu, Richard J. Tuffs, Giovanni Natale, Mark Norris, Mark Rushton, Meiert Grootes, Ben Carroll

Comments: 35 pages, 17 figures; Accepted for publication in the MNRAS

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

[71]  arXiv:2004.00847 (replaced) [pdf, other]

Title: FLASH Early Science -- Discovery of an intervening HI 21-cm absorber from an ASKAP survey of the GAMA 23 field

Authors: J. R. Allison, E. M. Sadler, S. Bellstedt, L. J. M. Davies, S. P. Driver, S. L. Ellison, M. Huynh, A. D. Kapinska, E. K. Mahony, V. A. Moss, A. S. G. Robotham, M. T. Whiting, S. J. Curran, J. Darling, A. W. Hotan, R. W. Hunstead, B. S. Koribalski, C. D. P. Lagos, M. Pettini, K. A. Pimbblet, M. A. Voronkov

Comments: 15 pages, 12 figures, accepted for publication in MNRAS

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

[72]  arXiv:2004.02884 (replaced) [pdf, other]

Title: A Hard X-ray Test of HCN Enhancements as a Tracer of Embedded Black Hole Growth

Authors: G. C. Privon, C. Ricci, S. Aalto, S. Viti, L. Armus, T. Díaz-Santos, E. González-Alfonso, K. Iwasawa, D. L. Jeff, E. Treister, F. Bauer, A. S. Evans, P. Garg, R. Herrero-Illana, J. M. Mazzarella, K. Larson, L. Blecha, L. Barcos-Muñoz, V. Charmandaris, S. Stierwalt, M. A. Pérez-Torres

Comments: 14 pages, 4 figures. accepted for publication in The Astrophysical Journal

Journal-ref: ApJ 893 149 (2020)

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

[73]  arXiv:2004.03514 (replaced) [pdf, other]

Title: Identification of MHD compressible modes in interstellar plasma with synchrotron emission polarization

Authors: Alexey Chepurnov, Alex Lazarian, Reinaldo Santos de Lima, Sarah Appleby

Subjects: Astrophysics of Galaxies (astro-ph.GA); Plasma Physics (physics.plasm-ph)

[74]  arXiv:2004.03551 (replaced) [pdf, other]

Title: Optical to near-infrared transmission spectrum of the warm sub-Saturn HAT-P-12b

Authors: Ian Wong, Björn Benneke, Peter Gao, Heather A. Knutson, Yayaati Chachan, Gregory W. Henry, Drake Deming, Tiffany Kataria, Graham K. H. Lee, Nikolay Nikolov, David K. Sing, Gilda E. Ballester, Nathaniel J. Baskin, Hannah R. Wakeford, Michael H. Williamson

Comments: 25 pages, 19 figures, accepted for publication in AJ, updated with proof corrections

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

[75]  arXiv:2004.03679 (replaced) [pdf, other]

Title: Solar disk center shows scattering polarization in the Sr I 4607 Å line

Authors: Franziska Zeuner, Rafael Manso Sainz, Alex Feller, Michiel van Noort, Sami K. Solanki, Francisco A. Iglesias, Kevin Reardon, Valentín Martínez Pillet

Comments: 15 pages , 6 figures, revised

Journal-ref: The Astrophysical Journal Letters 893:L44 (2020)

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

[76]  arXiv:2004.06137 (replaced) [pdf, other]

Title: Detectability of kilonovae in optical surveys: $post$-$mortem$ examination of the LVC O3 run follow-up

Authors: A. Sagués Carracedo, M. Bulla, U. Feindt, A. Goobar

Comments: 11 pages, 10 figures, 3 tables, submitted to MNRAS

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

[77]  arXiv:2004.06155 (replaced) [pdf, other]

Title: Spherically symmetric static black holes in Einstein-aether theory

Authors: Chao Zhang, Xiang Zhao, Kai Lin, Shaojun Zhang, Wen Zhao, Anzhong Wang

Comments: revtex4, 9 figures, 6 tables. Some typos are corrected, and a family of exact solutions is added

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

[78]  arXiv:2004.08484 (replaced) [pdf, other]

Title: Probing variation of the fine-structure constant using the strong gravitational lensing

Authors: L. R. Colaço, R. F. L. Holanda, R. Silva

Comments: 8 pages, 3 figures, 1 table

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

[79]  arXiv:2004.10709 (replaced) [pdf, other]

Title: Ionization Yield in Silicon for eV-Scale Electron-Recoil Processes

Authors: Karthik Ramanathan, Noah Kurinsky

Comments: 13 pages, 10 figures

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex); Data Analysis, Statistics and Probability (physics.data-an); Instrumentation and Detectors (physics.ins-det)

[80]  arXiv:2004.11108 (replaced) [pdf, other]

Title: Colors and patterns of black hole X-ray binary GX 339-4

Authors: Ilia A. Kosenkov (1 and 2), Alexandra Veledina (1, 3, 4), Valery F. Suleimanov (4, 5, 6), Juri Poutanen (1, 3, 4) ((1) Department of Physics and Astronomy, University of Turku, Finland, (2) St.Petersburg State University, Russia, (3) Nordita, KTH Royal Institute of Technology and Stockholm University, Sweden, (4) Space Research Institute of the RAS, Russia, (5) Institut für Astronomie und Astrophysik, Kepler Center for Astro and Particle Physics, Universität Tübingen, Germany, (6) Kazan Federal University, Russia)

Comments: Accepted for publication in Astronomy & Astrophysics, 19 pages, 6 tables, 18 figures

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

[81]  arXiv:2004.11224 (replaced) [pdf, other]

Title: Mechanical feedback effects on primordial black hole accretion

Authors: Valenti Bosch-Ramon, Nicola Bellomo

Comments: 10 pages, 6 figures, accepted for publication in Astronomy and Astrophysics (main author email corrected: -&gt; vbosch@fqa.ub.edu)

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE)

• New submissions
• Cross-lists
• Replacements