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New submissions for Mon, 6 Apr 20

[1]  arXiv:2004.01188 [pdf, other]

Title: Vortices and waves in light dark matter

Authors: Lam Hui, Austin Joyce, Michael J. Landry, Xinyu Li

Comments: 60 pages, 11 figures

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

In a galactic halo like the Milky Way, bosonic dark matter particles lighter than about $100$ eV have a de Broglie wavelength larger than the average inter-particle separation and are therefore well described as a set of classical waves. This applies to, for instance, the QCD axion as well as to lighter axion-like particles such as fuzzy dark matter. We show that the interference of waves inside a halo inevitably leads to vortices, locations where chance destructive interference takes the density to zero. The phase of the wavefunction has non-trivial winding around these points. This can be interpreted as a non-zero velocity circulation, so that vortices are sites where the fluid velocity has a non-vanishing curl. Using analytic arguments and numerical simulations, we study the properties of vortices and show they have a number of universal features: (1) In three spatial dimensions, the generic defects take the form of vortex rings. (2) On average there is about one vortex ring per de Broglie volume and (3) generically only single winding ($\pm 1$) vortices are found in a realistic halo. (4) The density near a vortex scales as $r^2$ while the velocity goes as $1/r$, where $r$ is the distance to vortex. (5) A vortex segment moves at a velocity inversely proportional to its curvature scale so that smaller vortex rings move faster, allowing momentary motion exceeding escape velocity. We discuss observational/experimental signatures from vortices and, more broadly, wave interference. In the ultra-light regime, gravitational lensing by interference substructures leads to flux anomalies of $5-10 \%$ in strongly lensed systems. For QCD axions, vortices lead to a diminished signal in some detection experiments but not in others. We advocate the measurement of correlation functions by axion detection experiments as a way to probe and capitalize on the expected interference substructures.

[2]  arXiv:2004.01191 [pdf, other]

Title: The fate of disk galaxies in IllustrisTNG clusters

Authors: Gandhali D. Joshi, Annalisa Pillepich, Dylan Nelson, Federico Marinacci, Volker Springel, Vicente Rodriguez-Gomez, Mark Vogelsberger, Lars Hernquist

Comments: Submitted to MNRAS. Key figures: 4 & 17. Comments are welcome

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

We study the stellar morphological evolution of disk galaxies within clusters in the TNG50 and TNG100 runs from the IllustrisTNG simulation suite. We select satellites of masses $10^{9.7}<=M_{*,z=0}/M_{sun}<=10^{11.6}$ residing in clusters of total masses $10^{14}<=M_{\text{200c,z=0}}/M_{sun}<10^{14.6}$ at z=0 and study those that were disks at accretion according to a kinematic morphology indicator (the circularity fraction). The galaxies' histories are traced from the time of accretion to $z=0$ and compared to a control sample of central galaxies mass-matched at the time of accretion. Most cluster disks become non-disky by z=0, in stark contrast with the control disks, of which a significant fraction remains disky over the same timescales. The transformation to non-disky morphologies is accompanied by gas removal and star formation quenching for both cluster and control galaxies. However, cluster disks that become non-disky by z=0 have lost dark matter (DM) mass and show little growth or a loss of stellar mass, whereas the corresponding control disks show significant growth in both components. Most cluster satellites change their morphologies on similar timescales regardless of stellar mass, in ~0.5-4 Gyr after accretion. Cluster disks that have had more numerous and closer pericentric passages show the largest change in morphology. Morphological change in both cluster and control disks requires the presence of a gravitational perturbation to drive stellar orbits to non-disky configurations, along with gas removal/heating to prevent replenishment of the disk through continued star-formation. For cluster disks, the perturbation is in the form of impulsive tidal shocking at pericentres and not tidal stripping of the outer disk stellar material, whereas for control disks, a combination of mergers and AGN feedback appears to be the key driving force behind morphological transformations.

[3]  arXiv:2004.01195 [pdf, other]

Title: Neutron-capture elements in dwarf galaxies III: A homogenized analysis of 13 dwarf spheroidal and ultra-faint galaxies

Authors: Moritz Reichert, Camilla J. Hansen, Michael Hanke, Ása Skúladóttir, Almudena Arcones, Eva K. Grebel

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

We present a large homogeneous set of stellar parameters and abundances across a broad range of metallicities, involving $13$ classical dwarf spheroidal (dSph) and ultra-faint dSph (UFD) galaxies. In total this study includes $380$ stars in Fornax, Sagittarius, Sculptor, Sextans, Carina, Ursa Minor, Draco, Reticulum II, Bootes I, Ursa Major II, Leo I, Segue I, and Triangulum II. This sample represents the largest, homogeneous, high-resolution study of dSph galaxies to date. With our homogeneously derived catalog, we are able to search for similar and deviating trends across different galaxies. We investigate the mass dependence of the individual systems on the production of $\alpha$-elements, but also try to shed light on the long-standing puzzle of the dominant production site of r-process elements. We use data from the Keck observatory archive and the ESO reduced archive to reanalyze stars from these $13$ dSph galaxies. We automatize the step of obtaining stellar parameters, but run a full spectrum synthesis to derive all abundances except for iron. The homogenized set of abundances yielded the unique possibility to derive a relation between the onset of type Ia supernovae and the stellar mass of the galaxy. Furthermore, we derived a formula to estimate the evolution of $\alpha$-elements. Placing all abundances consistently on the same scale is crucial to answer questions about the chemical history of galaxies. By homogeneously analysing Ba and Eu in the 13 systems, we have traced the onset of the s-process and found it to increase with metallicity as a function of the galaxy's stellar mass. Moreover, the r-process material correlates with the $\alpha$-elements indicating some co-production of these, which in turn would point towards rare core-collapse supernovae rather than binary neutron star mergers as host for the r-process at low [Fe/H] in the investigated dSph systems.

[4]  arXiv:2004.01196 [pdf, other]

Title: Fundamental differences in the radio properties of red and blue quasars: Insight from the LOFAR Two-metre Sky Survey (LoTSS)

Authors: D. J. Rosario, V. A. Fawcett, L. Klindt, D. M. Alexander, L. Morabito (Durham University), S. Fotopoulou (University of Bristol), E. Lusso (University of Florence, INAF-Arcetri), G. Calistro Rivera (ESO)

Comments: 20 pages, 16 Figures. Accepted for publication in MNRAS

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

Red quasi-stellar objects (QSOs) are a subset of the luminous end of the cosmic population of active galactic nuclei (AGN), most of which are reddened by intervening dust along the line-of-sight towards their central engines. In recent work from our team, we developed a systematic technique to select red QSOs from the Sloan Digital Sky Survey (SDSS), and demonstrated that they have distinctive radio properties using the Faint Images of the Radio Sky at Twenty centimeters (FIRST) radio survey. Here we expand our study using low-frequency radio data from the LOFAR Two-metre Sky Survey (LoTSS). With the improvement in depth that LoTSS offers, we confirm key results: compared to a control sample of normal "blue" QSOs matched in redshift and accretion power, red QSOs have a higher radio detection rate and a higher incidence of compact radio morphologies. For the first time, we also demonstrate that these differences arise primarily in sources of intermediate radio-loudness: radio-intermediate red QSOs are $\times 3$ more common than typical QSOs, but the excess diminishes among the most radio-loud and the most radio-quiet systems in our study. We develop Monte-Carlo simulations to explore whether differences in star formation could explain these results, and conclude that, while star formation is an important source of low-frequency emission among radio-quiet QSOs, a population of AGN-driven compact radio sources is the most likely cause for the distinct low-frequency radio properties of red QSOs. Our study substantiates the conclusion that fundamental differences must exist between the red and normal blue QSO populations.

[5]  arXiv:2004.01197 [pdf, other]

Title: Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars

Authors: Victoria A. Fawcett, David M. Alexander, David J. Rosario, Lizelke Klindt, Sotiria Fotopoulou, Elisabeta Lusso, Leah K. Morabito, Gabriela Calistro Rivera

Comments: To be published in MNRAS: 17 pages, 17 figures and 3 tables

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

We have recently used the Faint Images of the Radio Sky at Twenty-centimeters (FIRST) survey to show that red quasars have fundamentally different radio properties to typical blue quasars: a significant (factor $\sim3$) enhancement in the radio-detection fraction, which arises from systems around the radio-quiet threshold with compact ($<5''$) radio morphologies. To gain greater insight into these physical differences, here we use the DR14 Sloan Digital Sky Survey (SDSS) and more sensitive, higher resolution radio data from the Very Large Array (VLA) Stripe 82 (S82) and VLA-COSMOS 3 GHz (C3GHz) surveys. With the S82 data, we perform morphological analyses at a resolution and depth three times that of the FIRST radio survey, and confirm an enhancement in radio-faint and compact red quasars over typical quasars; we now also find tentative evidence for an enhancement in red quasars with slightly extended radio structures ($16-43$ kpc at $z=1.5$). These analyses are complemented by C3GHz, which is deep enough to detect radio emission from star-formation processes. From our data we find that the radio enhancement from red quasars is due to AGN activity on compact scales ($< 43$ kpc) for radio-intermediate-radio-quiet sources ($-5<R<-3.4$, where $R=L_{1.4GHz}/L_{6 \mu m}$), which decreases at $R<-5$ as the radio emission from star-formation starts to dilute the AGN component. Overall our results argue against a simple orientation scenario and are consistent with red quasars representing a younger, earlier phase in the overall evolution of quasars.

[6]  arXiv:2004.01198 [pdf, other]

Title: Apsidal Clustering following the Inclination Instability

Authors: Alexander Zderic, Angela Collier, Maria Tiongco, Ann-Marie Madigan

Comments: 6 pages, 4 figures, submitted to Astrophysical Journal Letters

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

Disks of low-mass bodies on high-eccentricity orbits in near-Keplerian potentials can be dynamically unstable to buckling out of the plane. In this letter, we present $N$-body simulations of the long-term behavior of such a system, finding apsidal clustering of the orbits in the disk plane. The timescale over which the clustering is maintained increases with number of particles, suggesting that lopsided configurations are stable at large $N$. This discovery may explain the observed apsidal ($\varpi$) clustering of extreme trans-Neptunian Objects in the outer solar system.

[7]  arXiv:2004.01204 [pdf]

Title: Disk tearing in a young triple star system with misaligned disk/orbit planes

Authors: Stefan Kraus, Alexander Kreplin, Alison K. Young, Matthew R. Bate, John D. Monnier, Tim J. Harries, Henning Avenhaus, Jacques Kluska, Anna S. E. Laws, Evan A. Rich, Matthew Willson, Alicia N. Aarnio, Fred C. Adams, Sean M. Andrews, Narsireddy Anugu, Jaehan Bae, Theo ten Brummelaar, Nuria Calvet, Michel Curé, Claire L. Davies, Jacob Ennis, Catherine Espaillat, Tyler Gardner, Lee Hartmann, Sasha Hinkley, Aaron Labdon, Cyprien Lanthermann, Jean-Baptiste LeBouquin, Gail H. Schaefer, Benjamin R. Setterholm, David Wilner, Zhaohuan Zhu

Comments: 74 pages, 3+19 Figures, 6 Tables, paper under review at 'Science' (version prior to peer review)

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

In young multiple stellar systems the gravitational influence of the stars shapes the circumstellar disk, controlling accretion and the material available for planet formation. Our observations of the triple system GW Orionis provide direct evidence for disk tearing, where the gravitational torques due to misaligned disk/orbit planes warp the disk and break the inner disk into precessing rings. We image an eccentric ring that is misaligned with respect to the orbital planes and outer disk, and casts shadows on the strongly warped intermediate disk. Our ring/warp geometry constraints and the fully characterized perturber orbits make the system a potential Rosetta Stone for studying disk hydrodynamics. The ring might offer suitable conditions for planet formation, providing a mechanism for forming wide-separation planets on highly oblique orbits.

[8]  arXiv:2004.01205 [pdf, other]

Title: The Origin of Pulsating Ultra-Luminous X-ray Sources: Intermediate-Mass X-ray Binaries containing Neutron Star Accretors

Authors: Devina Misra, Tassos Fragos, Thomas Tauris, Emmanouil Zapartas, David R. Aguilera-Dena

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

Ultra-luminous X-ray sources (ULXs) are X-ray sources located off-galactic centre and have luminosities exceeding the Eddington limit of a stellar-mass black hole ($L_X>10^{39}\;{\rm erg\,s}^{-1}$). With the discovery of X-ray pulsations in some of these objects (e.g. M82 X-2), we know a part of the ULX population has a neutron star (NS) accretor. We present systematic modelling of intermediate-mass X-ray binaries (IMXBs; donor-star mass range $2.0$ to $8.0\;$M$_{\odot}$) to explain the formation of this sub-population of ULXs. Using MESA, we explore the allowed initial parameter space of binary systems consisting of a neutron star and an intermediate-mass donor star, that could explain the observed properties of ULXs. Our simulations take into account beaming effects and also include stellar rotation, tides, general angular momentum losses, and a detailed and self-consistent calculation of the mass-transfer rate. Exploring the initial parameters that lead to the formation of neutron-star ULXs, we study the conditions that lead to dynamical stability of these systems, which depends strongly on the response of the donor star to mass loss. Using two values for the initial NS mass ($1.3\;$M$_{\odot}$ and $2.0\;$M$_{\odot}$) we find that IMXBs can produce NS-ULXs with typical time-averaged isotropic-equivalent X-ray luminosities between $10^{39}$--$10^{41}\;{\rm erg\,s}^{-1}$ on a timescale of up to $\sim\!1.0\;$Myr for the lower luminosities, assuming geometrical beaming. Finally, we estimate their likelihood of detection, the types of white-dwarf remnants left behind by the donors, as well as the total amount of mass accreted by the neutron stars. We also compare our results to the observed pulsating ULXs and infer their initial parameters. Our results suggest that a large subset of the observed pulsating ULX population can be explained by IMXBs in a super-Eddington mass-transfer phase.

[9]  arXiv:2004.01210 [pdf, other]

Title: Fitting string inflation to real cosmological data

Authors: Michele Cicoli, Eleonora Di Valentino

Comments: 12 pages, 8 figures

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

In this paper we show how the string landscape can be constrained using observational data. We illustrate this idea by focusing on Fibre Inflation which is a promising class of string inflationary models in type IIB flux compactifications. We determine the values of the microscopic flux-dependent parameters which yield the best fit to the most recent cosmological datasets.

[10]  arXiv:2004.01263 [pdf, other]

Title: The highly variable time evolution of star-forming cores identified with dendrograms

Authors: Rachel A. Smullen, Kaitlin M. Kratter, Stella S. R. Offner, Aaron T. Lee, Hope How-Huan Chen

Comments: 20 pages, 17 figures. Submitted to MNRAS

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

We investigate the time evolution of dense cores identified in molecular cloud simulations using dendrograms, which are a common tool to identify hierarchical structure in simulations and observations of star formation. We develop an algorithm to link dendrogram structures through time using the three-dimensional density field from magnetohydrodynamical simulations, thus creating histories for all dense cores in the domain. We find that the population-wide distributions of core properties are relatively invariant in time, and quantities like the core mass function match with observations. Despite this consistency, an individual core may undergo large (>40%), stochastic variations due to the redefinition of the dendrogram structure between timesteps. This variation occurs independent of environment and stellar content. We identify a population of short-lived (<200 kyr) overdensities masquerading as dense cores that may comprise ~20% of any time snapshot. Finally, we note the importance of considering the full history of cores when interpreting the origin of the initial mass function; we find that, especially for systems containing multiple stars, the core mass defined by a dendrogram leaf in a snapshot is typically less than the final system stellar mass. This work reinforces that there is no time-stable density contour that defines a star-forming core. The dendrogram itself can induce significant structure variation between timesteps due to small changes in the density field. Thus, one must use caution when comparing dendrograms of regions with different ages or environment properties because differences in dendrogram structure may not come solely from the physical evolution of dense cores.

[11]  arXiv:2004.01273 [pdf, ps, other]

Title: Infrared Colours and Spectral Energy Distributions of Hard X-ray Selected Obscured and Compton-thick AGN

Authors: Ece Kilerci-Eser, Tomotsugu Goto, Tolga Guver, Asli Tuncer, Oguz Han Atas

Comments: 20 pages, 12 figures. Accepted for publication in MNRAS

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

We investigate infrared colours and spectral energy distributions (SEDs) of 338 X-ray selected AGN from Swift-BAT 105-month survey catalogue that have AKARI detection, in order to find a new selection criteria for Compton-thick AGN. By combining data from Galaxy Evolution Explore (GALEX), Sloan Digital Sky Survey (SDSS) Data Release 14 (DR14), Two Micron All Sky Survey (2MASS), Wide-field Infrared Survey Explorer (WISE), AKARI and Herschel for the first time we perform ultraviolet (UV) to far-infrared (FIR) SED fitting 158 Swift BAT AGN by CIGALE and constrain the AGN model parameters of obscured and Compton-thick AGN. The comparison of average SEDs show while the mid-IR (MIR) SEDs are similar for the three AGN populations, optical/UV and FIR regions have differences. We measure the dust luminosity, the pure AGN luminosity and the total infrared (IR) luminosity. We examine the relationships between the measured infrared luminosities and the hard X-ray luminosity in the 14-195 keV band. We show that the average covering factor of Compton-thick AGN is higher compared to the obscured and unobscured AGN. We present a new infrared selection for Compton-thick AGN based on MIR and FIR colours ([9$\mu$m - 22$\mu$m]$ > 3.0$ and [22$\mu$m - 90$\mu$m]$ < 2.7$) from WISE and AKARI. We find two known Compton-thick AGN that are not included in the Swift-BAT sample, and conclude that MIR colours covering 9.7$\mu$m silicate absorption and MIR continuum can be a promising new tool to identify Compton-thick AGN.

[12]  arXiv:2004.01308 [pdf, other]

Title: A flare in the optical spotted in the changing-look Seyfert NGC 3516

Authors: D. Ilic, V. Oknyansky, L.C. Popovic, S.S. Tsygankov, A.A. Belinski, A.M. Tatarnikov, A.V. Dodin, N.I. Shatsky, N.P. Ikonnikova, N. Rakic, A. Kovacevic, S. Marceta-Mandic, M.A. Burlak, E.O. Mishin, N.V. Metlova, S.A. Potanin, S.G. Jeltouhov

Comments: 7 pages, 6 figures, accepted in A&A

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

We present observations from the short-term intensive optical campaign (from Sep2019 to Jan2020) of the changing-look Seyfert NGC 3516. This AGN is known to have strong optical variability and has changed its type in the past. It has been in the low-activity state in the optical since 2013, with some rebrightening from the end of 2015 to the beginning of 2016, after which it remained dormant. We aim to study the optical variability of NGC 3516 from the new observations in U- and B-bands, and examine the profiles of the optical broad emission lines, in order to demonstrate that this object may be going into a new state of activity. NGC 3516 has been monitored intensively for the past 4 months with an automated telescope in U and B filters, enabling accurate photometry of 0.01 precision. When an increase in brightness was spotted, the spectral observations were triggered. We support our analysis of past-episodes of violent variability with the UV and X-ray long-term light curves constructed from the archival Swift/UVOT and XRT data. The increase of the photometric magnitude is seen in both U and B filters to a maximum amplitude of 0.25 mag and 0.11 mag, respectively. During the flare, we observe stronger forbidden high-ionization iron lines than reported before, as well as the complex broad H{\alpha} and H{\beta} lines. This is especially seen in H{\alpha} that appears to be double-peaked. It seems that a very broad component of ~10000 km/s width in the Balmer lines is appearing. The trends in the optical, UV, and X-ray light curves are similar, with the amplitudes of variability significantly larger in the case of UV and X-ray. The increase of the continuum emission, the variability of the coronal lines, and the very broad component in the Balmer lines may indicate that AGN of NGC 3516 is finally leaving the low-activity state in which it has been in the last ~3 years.

[13]  arXiv:2004.01338 [pdf, other]

Title: Extinction at the Galactic Center Using Near- and Mid-infrared Broadband Photometry: A Twist on the Rayleigh-Jeans Color Excess Method

Authors: R. Deno Stelter (1, 2, 3), Stephen S. Eikenberry (3) ((1) Center for Adaptive Optics, UC OBservatories, UC Santa Cruz, (2) Astronomy Department, UC Santa Cruz, (3) Astronomy Department, University of Florida)

Comments: Submitted to ApJ with revisions. 21 pages, 11 figures

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

We present an extinction map of the inner $\sim$\SI{15}{\arcminute} by {16}{\arcminute} of the Galactic Center (GC) with map `pixels' measuring \SI{5}{\arcsecond} $\times$ \SI{5}{\arcsecond} using integrated light color measurements in the near- and mid-infrared. We use a variant of the Rayleigh-Jeans Color Excess (RJCE) method first described by Majewski et al. (2011) as the basis of our work, although we have approached our problem with a Bayesian mindset and dispensed with point-source photometry in favor of surface photometry, turning the challenge of the extremely crowded field at the GC into an advantage. Our results show that extinction at the GC is not inconsistent with a single power law coefficient, $\beta=2.03\pm0.06$, and compare our results with those using the Red Clump (RC) point-source photometry method of extinction estimation. We find that our measurement of $\beta$ and its apparent lack of spatial variation are in agreement with prior studies, despite the bimodal distribution of values in our extinction map at the GC with peaks at \num{5} and \SI{7.5}{mag}. This bimodal nature of extinction is likely due to the InfraRed Dark Clouds that obscure portions of the inner GC field. We present our extinction law and map and de-reddened NIR CMDs and color-color diagram of the GC region using the point-source catalog of IR sources compiled by DeWitt et al. (2010). The de-reddening is limited by the error in the extinction measurement (typically \SI{0.6}{mag}), which is affected by the size of our map pixels and is not fine-grained enough to separate out the multiple stellar populations present toward the GC.

[14]  arXiv:2004.01340 [pdf, other]

Title: The Nature of Ultra-diffuse Galaxies in Distant Massive Galaxy Clusters: Abell 370 in the Hubble Frontier Fields

Authors: Jeong Hwan Lee, Jisu Kang, Myung Gyoon Lee, In Sung Jang

Comments: Accepted for publication in ApJ, 25 pages, 16 figures, 7 tables

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

We report the discovery of ultra-diffuse galaxies (UDGs) in Abell 370 ($z=0.375$). We find 46 UDGs in Abell 370 from the images of the Hubble Frontier Fields (HFF). Most UDGs are low-luminosity red sequence galaxies, while a few of them are blue UDGs. We estimate the abundance of UDGs in Abell 370, $N(\rm UDG)=644\pm104$. Combining these results with those of Abell S1063 ($z=0.348$) and Abell 2744 ($z=0.308$) \citep{Lee17}, we derive a mean radial number density profile of UDGs in the three clusters. The number density profiles of UDGs and bright galaxies show a discrepancy in the central region of the clusters: the profile of UDGs shows a flattening as clustercentric distance decreases, while that of bright galaxies shows a continuous increase. This implies that UDGs are prone to disruption in the central region of the clusters. The relation between the abundance of UDGs and virial masses of their host systems is described by a power-law with an index nearly one: $N({\rm UDG})\propto M_{200}^{0.99\pm0.05}$ for $M_{200}>10^{13}~M_{\odot}$. We estimate approximately dynamical masses of UDGs using the fundamental manifold method, and find that most UDGs have dwarf-like masses $(M_{200}<10^{11}$ $M_{\odot})$. This implies that most UDGs have a dwarf-like origin and a small number of them could be failed $L^{*}$ galaxies. These results suggest that multiple origins may contribute to the formation and evolution of UDGs in massive galaxy clusters.

[15]  arXiv:2004.01342 [pdf, other]

Title: Formation and Evolution of Disks around Young Stellar Objects

Authors: Bo Zhao, Kengo Tomida, Patrick Hennebelle, John J. Tobin, Anaelle Maury, Tomoya Hirota, Álvaro Sánchez-Monge, Rolf Kuiper, Anna Rosen, Asmita Bhandare, Marco Padovani, Yueh-Ning Lee

Comments: 57 pages, Space Science Reviews, topical collection Star Formation

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

Recent observations have suggested that circumstellar disks may commonly form around young stellar objects. Although the formation of circumstellar disks can be a natural result of the conservation of angular momentum in the parent cloud, theoretical studies instead show disk formation to be difficult from dense molecular cores magnetized to a realistic level, owing to efficient magnetic braking that transports a large fraction of the angular momentum away from the circumstellar region. We review recent progress in the formation and early evolution of disks around young stellar objects of both low-mass and high-mass, with an emphasis on mechanisms that may bridge the gap between observation and theory, including non-ideal MHD effects and asymmetric perturbations in the collapsing core (e.g., magnetic field misalignment and turbulence). We also address the associated processes of outflow launching and the formation of multiple systems, and discuss possible implications in properties of protoplanetary disks.

[16]  arXiv:2004.01393 [pdf, other]

Title: Reconstruction of late-time cosmology using Principal Component Analysis

Authors: Ranbir Sharma, Ankan Mukherjee, H. K. Jassal

Comments: 21 pages, 8 figures

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

We reconstruct late-time cosmology in a model-independent manner using the technique of Principal Component Analysis (PCA). In particular, we focus on the reconstruction of the dark energy equation of state parameters from two different observational data sets, supernova type Ia data, and the Hubble parameter data. To achieve this reconstruction, we have adopted two different techniques. The first is a derived approach wherein we reconstruct the observable quantities of the data sets, namely the Hubble parameter and the supernova distance modulus from observations using PCA and subsequently reconstruct the allowed equation of state parameter. The other approach is a direct one where dark energy equation of state is reconstructed directly from the data sets. We show that a combination of PCA algorithm and calculation of correlation coefficients can be used as a tool of reconstruction. The derived approach is found to be statistically preferable over the direct approach. We have carried out the analysis with simulated data and observed data sets of Hubble parameter measurements and distance modulus measurements of type Ia supernova. The reconstructed equation of state indicates a slowly varying dark energy equation of state parameter.

[17]  arXiv:2004.01424 [pdf, other]

Title: Cosmological Parameter Estimation from the Two-Dimensional Genus Topology -- Measuring the Shape of the Matter Power Spectrum

Authors: Stephen A. Appleby, Changbom Park, Sungwook E. Hong, Ho Seong Hwang, Juhan Kim

Comments: ApJ submitted, comments welcome

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

We present measurements of the two-dimensional genus of the SDSS-III BOSS catalogs to constrain cosmological parameters governing the shape of the matter power spectrum. The BOSS data are divided into twelve concentric shells over the redshift range $0.2 < z < 0.6$, and we extract the genus from the projected two-dimensional galaxy density fields. We compare the genus amplitudes to their Gaussian expectation values, exploiting the fact that this quantity is relatively insensitive to non-linear gravitational collapse. The genus amplitude provides a measure of the shape of the linear matter power spectrum, and is principally sensitive to $\Omega_{\rm c}h^{2}$ and scalar spectral index $n_{\rm s}$. A strong negative degeneracy between $\Omega_{\rm c}h^{2}$ and $n_{\rm s}$ is observed, as both can increase small scale power by shifting the peak and tilting the power spectrum respectively. We place a constraint on the particular combination $n_{\rm s}^{3/2} \Omega_{\rm c}h^{2}$ -- we find $n_{\rm s}^{3/2} \Omega_{\rm c}h^{2} = 0.1121 \pm 0.0043$ after combining the LOWZ and CMASS data sets, assuming a flat $\Lambda$CDM cosmology. This result is practically insensitive to reasonable variations of the power spectrum amplitude and linear galaxy bias. Our results are consistent with the Planck best fit $n_{\rm s}^{3/2}\Omega_{\rm c}h^{2} = 0.1139 \pm 0.0009$.

[18]  arXiv:2004.01427 [pdf, other]

Title: The Hubble stream near a massive object: the exact analytical solution for the spherically-symmetric case

Authors: Anton N. Baushev

Comments: 5 pages, 2 figures

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

The gravitational field of a massive object (for instance, of a galaxy group or cluster) disturbs the Hubble stream, decreasing its speed. Dependence $v(r_0)$ of the radial velocity of the stream from the present-day radius $r_0$ can be directly observed and may provide valuable information about the cluster properties. We offer an exact analytical relationship $v(r_0)$ for a spherically-symmetric system.

[19]  arXiv:2004.01432 [pdf, other]

Title: Background Model for the Low-Energy Telescope of Insight-HXMT

Authors: Jin-Yuan Liao, Shu Zhang, Yong Chen, Juan Zhang, Jing Jin, Zhi Chang, Yu-Peng Chen, Ming-Yu Ge, Cheng-Cheng Guo, Gang Li, Xiao-Bo Li, Fang-Jun Lu, Xue-Feng Lu, Jian-Yin Nie, Li-Ming Song, Yan-Ji Yang, Yuan You, Hai-Sheng Zhao, Shuang-Nan Zhang

Comments: 24 pages, 17 figures, accepted by Journal of High Energy Astrophysics

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

With more than 150 blank sky observations at high Galactic latitude, we make a systematic study to the background of the Low Energy Telescope (LE) of the Hard X-ray Modulation Telescope (dubbed as Insight-HXMT). Both the on-ground simulation and the in-orbit observation indicate that the background spectrum mainly has two components. One is the particle background that dominates above 7 keV and its spectral shape is consistent in every geographical locations. Another is the diffuse X-ray background that dominates below 7 keV and has a stable spectrum less dependent of the sky region. The particle background spectral shape can be obtained from the blind detector data of all the blank sky observations, and the particle background intensity can be measured by the blind detector at 10-12.5 keV. The diffuse X-ray background in the high Galactic latitude can also be obtained from the blank sky spectra after subtracting the particle background. Based on these characteristics, we develop the background model for both the spectrum and the light curve. The systematic error for the background spectrum is investigated with different exposures (T_exp). For the spectrum with T_exp=1 ks, the average systematic errors in 1-7 keV and 1-10 keV are 4.2% and 3.7%, respectively. We also perform the systematic error analyses of the background light curves with different energy bands and time bins. The results show that the systematic errors for the light curves with different time bins are <8% in 1-10 keV.

[20]  arXiv:2004.01439 [pdf, other]

Title: Possible evidence of induced repetitive magnetic reconnection in a superflare from a young solar-type star

Authors: S. Mancuso, D. Barghini, D. Telloni

Comments: 7 pages, 5 figures, accepted for publication in A&A

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

We report the detection of multiple quasi-periodic pulsations (QPPs) observed during the flaring activity of KIC 8414845, a young, active solar-type star observed by the Kepler mission launched by NASA. We analyzed the QQP signal using a data-driven, nonparametric method called singular spectrum analysis (SSA), which has never been utilized previously for analyzing solar or stellar QPPs. Because it is not based on a prescribed choice of basis functions, SSA is particularly suitable for analyzing nonstationary, nonlinear signals such as those observed in QPPs during major flares. The analysis has revealed that the apparent anharmonic shape of the QPP in this superflare results from a superposition of two intrinsic modes of periods of 49 min and 86 min, which display quasi-harmonic behaviors and different modulation patterns. The two reconstructed signals are consistent with slow-mode transverse and/or longitudinal magnetohydrodynamic oscillations excited in a coronal loop inducing periodic releases of flaring energy in a nearby loop through a mechanism of repetitive reconnection. The peculiar amplitude modulation of the two modes evinced by SSA favors the interpretation of the observed QPP pattern as due to the excitation in a coronal loop of the second harmonic of a standing slow-mode magnetoacoustic oscillation and a global kink oscillation periodically triggering magnetic reconnection in a nearby loop. Concurrent interpretations cannot however be ruled out on the basis of the available data.

[21]  arXiv:2004.01448 [pdf, other]

Title: A tomographic map of the large-scale matter distribution using the eBOSS Stripe 82 Ly-$α$ forest

Authors: C. Ravoux, E. Armengaud, M. Walther, T. Etourneau, D. Pomarède, N. Palanque-Delabrouille, C. Yèche, J. Bautista, H. du Mas des Bourboux, S. Chabanier, K. Dawson, J.-M. Le Goff, B. Lyke, A. D. Myers, P. Petitjean, M. M. Pieri, J. Rich, G. Rossi, D. P. Schneider

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

The Lyman-$\alpha$ (hereafter Ly-$\alpha$) forest is a probe of large-scale matter density fluctuations at high redshift, $z > 2.1$. It consists of HI absorption spectra along individual lines-of-sight. If the line-of-sight density is large enough, 3D maps of HI absorption can be inferred by tomographic reconstruction. In this article, we investigate the Ly-$\alpha$ forest available in the Stripe 82 field ($220\,\mathrm{deg^{2}}$), based on the quasar spectra from SDSS Data Release DR16. The density of observed quasar spectra is $37\,\mathrm{deg^{-2}}$ with a mean pixel signal-to-noise ratio of two per angstrom. This study provides an intermediate case between the average SDSS density and that of the much denser but smaller CLAMATO survey. We derive a 3D map of large-scale matter fluctuations from these data, using a Wiener filter technique. The total volume of the map is $0.94\,\mathrm{h^{-3} Gpc^{3}}$. Its resolution is $13\,\mathrm{h^{-1} Mpc}$, which is related to the mean transverse distance between nearest lines-of-sight. From this map, we provide a catalog of voids and protocluster candidates in the cosmic web. The map-making and void catalog are compared to simulated eBOSS Stripe 82 observations. A stack over quasar positions provides a visualization of the Ly-$\alpha$ quasar cross-correlation. This tomographic reconstruction constitutes the largest-volume high-redshift 3D map of matter fluctuations.

[22]  arXiv:2004.01488 [pdf, other]

Title: SiO maser astrometry of the red transient V838 Monocerotis

Authors: Gisela N. Ortiz-Leon, Karl M. Menten, Tomasz Kaminski, Andreas Brunthaler, Mark J. Reid, Romuald Tylenda

Comments: Accepted for publication in A&A

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

We present multi-epoch observations with the VLBA of SiO maser emission in the v=1, J=1-0 transition at 43 GHz from the remnant of the red nova V838 Mon. We model the positions of maser spots to derive a parallax of 0.166+/-0.060 mas. Combining this parallax with other distance information results in a distance of 5.6+/-0.5 kpc, which agrees with an independent geometric distance of 6.1+/-0.6 kpc from modeling polarimetry images of V838 Mon's light echo. Combining these results, and including a weakly constraining Gaia DR2 parallax, yields a best estimate of distance of 5.9+/-0.4 kpc. The maser spots are located close to the peaks of continuum at ~225 GHz and SiO J=5-4 thermal emission detected with ALMA. The proper motion of V838 Mon confirms its membership in a small open cluster in the Outer spiral arm of the Milky Way.

[23]  arXiv:2004.01501 [pdf, other]

Title: High-Resolution Radio Observations of Five Optically Selected Type 2 Quasars

Authors: Máté Krezinger, Sándor Frey, Zsolt Paragi, Roger Deane

Comments: 13 pages, 2 figures, appeared in the open-access journal Symmetry (special issue: Astronomy and Symmetry)

Journal-ref: Symmetry, Vol. 12, No. 4, id. 527 (2020)

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

Many low-luminosity active galactic nuclei (AGNs) contain a compact radio core which can be observed with high angular resolution using very long baseline interferometry (VLBI). Combining arcsec-scale structural information with milliarcsec-resolution VLBI imaging is a useful way to characterise the objects and to find compact cores on parsec scales. VLBI imaging could also be employed to look for dual AGNs when the sources show kpc-scale double symmetric structure with flat or inverted radio spectra. We observed five such sources at redshifts 0.36 < z < 0.58 taken from an optically selected sample of Type 2 quasars with the European VLBI Network (EVN) at 1.7 and 5 GHz. Out of the five sources, only one (SDSS J1026-0042) shows a confidently detected compact VLBI core at both frequencies. The other four sources are marginally detected at 1.7 GHz only, indicating resolved-out radio structure and steep spectra. Using first-epoch data from the ongoing Karl G. Jansky Very Large Array Sky Survey, we confirm that indeed all four of these sources have steep radio spectra on arcsec scale, contrary to the inverted spectra reported earlier in the literature. However, the VLBI-detected source, SDSS J1026-0042, has a flat integrated spectrum. Radio AGNs that show kpc-scale symmetric structures with truly flat or inverted spectra could still be promising candidates of dual AGNs, to be targeted with VLBI observations in the future.

[24]  arXiv:2004.01503 [pdf, other]

Title: Disentangling Dust Components in SN 2010jl: The First 1400 Days

Authors: A. M. Bevan, K. Krafton, R. Wesson, J. E. Andrews, E. Montiel, M. Niculescu-Duvaz, M. J. Barlow, I. De Looze, G. C. Clayton

Comments: Accepted by ApJ. Author accepted manuscript. Accepted on 26/03/2020. Deposited on 03/04/20. 21 pages, 10 figures

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

The luminous Type IIn SN 2010jl shows strong signs of interaction between the SN ejecta and dense circumstellar material. Dust may be present in the unshocked ejecta, the cool, dense shell between the shocks in the interaction region, or in the circumstellar medium. We present and model new optical and infrared photometry and spectroscopy of SN 2010jl from 82 to 1367 days since explosion. We evaluate the photometric and spectroscopic evolution using the radiative transfer codes MOCASSIN and DAMOCLES, respectively. We propose an interaction scenario and investigate the resulting dust formation scenarios and dust masses. We find that SN 2010jl has been continuously forming dust based on the evolution of its infrared emission and optical spectra. There is evidence for pre-existing dust in the circumstellar medium as well as new dust formation in the cool, dense shell and/or ejecta. We estimate that 0.005--0.01M$_{\odot}$ of predominantly carbon dust grains has formed in SN 2010jl by ~1400d post-outburst.

[25]  arXiv:2004.01517 [pdf, other]

Title: A Tidal Disruption Event Candidate Discovered in the Active Galactic Nucleus SDSS J022700.77-042020.6

Authors: Zhu Liu, Dongyue Li, He-Yang Liu, Youjun Lu, Weimin Yuan, Liming Dou, Rong-Feng Shen

Comments: 15 pages, 7 figures, submitted to ApJ after minor revision

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

We report the discovery of a Tidal Disruption Event (TDE) candidate occurring in the Active Galactic Nucleus SDSS J022700.77-042020.6. A sudden increase in flux of J0227-0420 during the second half of 2009 is clearly shown in the long-term optical, UV, and NIR light curves. A plateau phase, following an initial decline, is seen in the NUV and optical u, g, r, i light curves. Moreover, we find possible evidence that the plateau phase in the NUV band may lag behind the optical ones by approximately 70-80 days with also a much shorter duration, i.e. $\sim$7-15 days against $\sim$40-50 days. The long-term NUV/optical (after the plateau phase), NIR and MIR light curves can be well characterized with a form of $L(t)\propto t^{-\beta}$, consistent with the expectation of a TDE. The plateaus can be explained if the stellar streams collide with the pre-existing AGN disk at different radii. Though the overall fallback rate decreases, the material in the outer disk gradually drifts inward and increases the local accretion rate at the inner region, producing the optical and UV plateaus. The possible lag between the optical and NUV plateaus can then be attributed to viscosity delay. The index $\beta$ of the NIR $J, H, K_s$ bands ($\sim1.4-3.3$) is steeper than that of the UV/optical ($\sim0.7-1.3$) and MIR bands ($\sim0.9-1.8$), which may suggest that a certain fraction of the dust in the inner region of the dusty torus may be sublimated during the TDE phase. Our results indicate that, due to collisions between stellar debris and pre-existing disk, the light curves of TDEs occurring in AGN may show distinctive features, which may shed new light on the accretion process.

[26]  arXiv:2004.01538 [pdf, other]

Title: Radio Afterglows of Very High Energy Gamma-Ray Bursts 190829A and 180720B

Authors: L. Rhodes (1, 2), A. J. van der Horst (3, 4), R. Fender (1, 5), I. Monageng (5, 6), G. E. Anderson (7), J. Antoniadis (2, 8, 9), M. F. Bietenholz (10, 11), M. Bottcher (12), J. S. Bright (1), C. Kouveliotou (3, 4), M. Kramer (2), S. E. Motta (1), D. R. A. Williams (1), P. A. Woudt (5). ((1) Oxford University, (2) Max Planck Insitut fur Radioastronomie, (3) George Washington University, (4) Astronomy, Physics and Statistics Institute of Sciences, (5) University of Cape Town, (6) South African Astronomical Observatory, (7) Curtin University, (8) University of Bonn, (9) University of Crete, (10) Hartebeesthoek Radio Observatory, (11) York University, (12) North-West University)

Comments: Submitted for publication in MNRAS

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

We present high cadence multi-frequency radio observations of the long Gamma-Ray Burst (GRB) 190829A, which was detected at photon energies above 100 GeV by the High Energy Stereoscopic System (H.E.S.S.). Observations with the Meer Karoo Array Telescope (MeerKAT, 1.3 GHz), and Arcminute Microkelvin Imager - Large Array (AMI-LA, 15.5 GHz) began one day post-burst and lasted nearly 200 days. We used complementary data from Swift X-Ray Telescope (XRT), which ran to 100 days post-burst. We detected a likely forward shock component with both MeerKAT and XRT up to over 100 days post-burst. Conversely, the AMI-LA light curve appears to be dominated by reverse shock emission until around 70 days post-burst when the afterglow flux drops below the level of the host galaxy. We also present previously unpublished observations of the other H.E.S.S.-detected GRB, GRB 180720B from AMI-LA, which shows likely forward shock emission that fades in less than 10 days. We present a comparison between the radio emission from the three GRBs with detected very high energy (VHE) gamma-ray emission and a sensitivity-limited radio afterglow sample. GRB 190829A has the lowest isotropic radio luminosity of any GRB in our sample, but the distribution of luminosities is otherwise consistent, as expected, with the VHE GRBs being drawn from the same parent distribution as the other radio-detected long GRBs.

[27]  arXiv:2004.01564 [pdf, other]

Title: First measurement of the total gravitational quadrupole moment of a black widow companion

Authors: Guillaume Voisin (LUTH), C Clark, R Breton, V. Dhillon, M Kennedy, D Mata-Sánchez

Comments: MNRAS, in press

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

We present the first measurement of the gravitational quadrupole moment of the companion star of a spider pulsar, namely the black widow PSR J2051$-$0827. To this end we have re-analysed radio timing data using a new model which is able to account for periastron precession caused by tidal and centrifugal deformations of the star as well as by general relativity. The model allows for a time-varying component of the quadrupole moment, thus self-consistently accounting for the ill-understood orbital period variations observed in these systems. Our analysis results in the first detection of orbital precession in a spider system at $\dot{\omega} = -68.6_{-0.5}^{+0.9}$ deg/yr and the most accurate determination of orbital eccentricity for PSR J2051$-$0827 with $e = (4.2 \pm 0.1) \times 10^{-5}$. We show that the variable quadrupole component is about 100 times smaller than the average quadrupole moment $\bar{Q} = -2.2_{-1}^{+0.6} \times 10^{41}$ kg.m$^2$. We discuss how accurate modelling of high precision optical light curves of the companion star will allow its apsidal motion constant to be derived from our results.

[28]  arXiv:2004.01594 [pdf, other]

Title: A family portrait of disk inner rims around Herbig Ae/Be stars: Hunting for warps, rings, self shadowing, and misalignments in the inner astronomical units

Authors: J. Kluska, J.-P. Berger, F. Malbet, B. Lazareff, M. Benisty, J.-B. Le Bouquin, O.Absil, F. Baron, A. Delboulbé, G. Duvert, A. Isella, L. Jocou, A. Juhasz, S. Kraus, R. Lachaume, F. Ménard, R. Millan-Gabet, J. D. Monnier, T. Moulin, K. Perraut, C. Pinte, S. Rochat, F. Soulez, M. Tallon, W.-F. Thi, E. Thiébaut, W. Traub, G. Zins

Comments: Accepted in A&A, 24pages, 22 figures

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

The innermost astronomical unit in protoplanetary disks is a key region for stellar and planet formation, as exoplanet searches have shown a large occurrence of close-in planets that are located within the first au around their host star. We aim to reveal the morphology of the disk inner rim using near-infrared interferometric observations with milli-arcsecond resolution provided by infrared interferometry. We provide reconstructed images of 15 objects selected from the Herbig AeBe survey carried out with PIONIER at the VLTI, using SPARCO. We find that 40% of the systems are centrosymmetric at the angular resolution of the observations. For the rest of the objects, we find evidence for asymmetric emission due to moderate-to-strong inclination of a disk-like structure for 30% of the objects and noncentrosymmetric morphology due to a nonaxisymmetric and possibly variable environment (30%). Among the systems with a disk-like structure, 20% show a resolved dust-free cavity. The image reconstruction process is a powerful tool to reveal complex disk inner rim morphologies. At the angular resolution reached by near-infrared interferometric observations, most of the images are compatible with a centrally peaked emission (no cavity). For the most resolved targets, image reconstruction reveals morphologies that cannot be reproduced by generic parametric models. Moreover, the nonaxisymmetric disks show that the spatial resolution probed by optical interferometers makes the observations of the near-infrared emission sensitive to temporal evolution with a time-scale down to a few weeks. The evidence of nonaxisymmetric emission that cannot be explained by simple inclination and radiative transfer effects requires alternative explanations, such as a warping of the inner disks. Interferometric observations can, therefore, be used to follow the evolution of the asymmetry of those disks at a sub-au scale.

[29]  arXiv:2004.01622 [pdf, other]

Title: Fast Particle Acceleration at Perpendicular Shocks with Uniform Upstream Magnetic Field and Strong Downstream Turbulence

Authors: Shoma F. Kamijima, Yutaka Ohira, Ryo Yamazaki

Comments: 7 pages, 4 figures, Submitted to ApJ

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

The shock waves produce relativistic particles via the diffusive shock acceleration (DSA) mechanism. Among various circumstances, fast acceleration has been expected for perpendicular shocks. We investigate the acceleration time and the energy spectrum of particles accelerated at a perpendicular shock. In our model, the upstream perpendicular magnetic field has no fluctuation, and the downstream region is highly turbulent. Then, the particle motion is the gyration in the upstream region and Bohm-like diffusion downstream. Under this situation, we derive an analytical form of the acceleration time. Using test particle simulations, the validity of our formula is verified. In addition, the energy spectrum of particles is the same as those predicted by standard DSA. Therefore, presently proposed mechanism simultaneously realizes the rapid acceleration and the canonical spectrum, $dN/dp \propto p^{-2}$, even if there is no upstream magnetic amplification.

[30]  arXiv:2004.01633 [pdf, ps, other]

Title: Stellar laboratories. X. New Cu IV - VII oscillator strengths and the first detection of copper and indium in hot white dwarfs

Authors: T. Rauch (1), S. Gamrath (2), P. Quinet (2,3), M. Demleitner (4), M. Knoerzer (1), K. Werner (1), J. W. Kruk (5) ((1) Institute for Astronomy and Astrophysics, Eberhard Karls University, Tuebingen, Germany, (2) Physique Atomique et Astrophysique, Universite de Mons - UMONS, Belgium, (3) IPNAS, Universite de Liege, Liege, Belgium, (4) Astronomisches Rechen-Institut, Zentrum fuer Astronomie, Ruprecht Karls University, Heidelberg, Germany, (5) NASA Goddard Space Flight Center, Greenbelt, USA)

Comments: 32 pages, 7 figures

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Atomic Physics (physics.atom-ph)

Accurate atomic data is an essential ingredient for the calculation of reliable non-local thermodynamic equilibrium (NLTE) model atmospheres that are mandatory for the spectral analysis of hot stars. We aim to search for and identify for the first time spectral lines of copper (atomic number Z = 29) and indium (Z = 49) in hot white dwarf (WD) stars and to subsequently determine their photospheric abundances. Oscillator strengths of Cu IV - VII were calculated to include radiative and collisional bound-bound transitions of Cu in our NLTE model-atmosphere calculations. Oscillator strengths of In IV - VI were compiled from the literature. We newly identified 1 Cu IV, 51 Cu V, 2 Cu VI, and 5 In Vlines in the ultraviolet (UV) spectrum of DO-type WD RE 0503-289. We determined the photospheric abundances of 9.3 X 10**-5 (mass fraction, 132 times solar) and 3.0 X 10**-5 (56 600 times solar), respectively; we also found Cu overabundances in the DA-type WD G191-B2B (6.3 X 10**-6, 9 times solar). All identified Cu IV - VI lines in the UV spectrum of RE 0503-289 were simultaneously well reproduced with our newly calculated oscillator strengths. With the detection of Cu and In in RE 0503-289, the total number of trans-iron elements (Z > 28) in this extraordinary WD reaches an unprecedented number of 18.

[31]  arXiv:2004.01645 [pdf, other]

Title: Modeling the formation of the $^{13}$C neutron source in AGB stars

Authors: Vescovi Diego, Cristallo Sergio

Comments: 4 pages, 2 figures, NPA IX proceedings. Accepted in JPCS

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

A major source of uncertainty in AGB models is the partial-mixing process of hydrogen, required for the formation of the so-called $^{13}$C pocket. Among the attempts to derive a self-consistent treatment of this physical process, there are 2D and 3D simulations of magnetic buoyancy. The $^{13}$C pocket resulting from mixing induced by magnetic buoyancy extends over a region larger than those so far assumed, showing an almost flat $^{13}$C distribution and a negligible amount of $^{14}$N. Recently, it has been proved to be a good candidate to match the records of isotopic abundance ratios of $s$-elements in presolar SiC grains. However, up to date such a magnetic mixing has been applied in post-process calculations only, being never implemented in a stellar evolutionary code. Here we present new stellar models, performed with the 1-d hydrostatic FUNS evolutionary code, which include magnetic buoyancy. We comment the resulting $s$-process distributions and show preliminary comparisons to spectroscopic observations and pre-solar grains measurements.

[32]  arXiv:2004.01666 [pdf, other]

Title: The Post-Limber Weak Lensing Bispectrum, Reduced Shear Correction, and Magnification Bias Correction

Authors: Anurag C. Deshpande, Thomas D. Kitching

Comments: 10 pages, 4 figures. Submitted to Phys. Rev. D

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

The significant increase in precision that will be achieved by Stage IV cosmic shear surveys means that several currently used theoretical approximations may cease to be valid. An additional layer of complexity arises from the fact that many of these approximations are interdependent; the procedure to correct for one involves making another. Two such approximations that must be relaxed for upcoming experiments are the reduced shear approximation and the effect of neglecting magnification bias. Accomplishing this involves the calculation of the convergence bispectrum; typically subject to the Limber approximation. In this work, we compute the post-Limber convergence bispectrum, and the post-Limber reduced shear and magnification bias corrections to the angular power spectrum for a Euclid-like survey. We find that the Limber approximation significantly overestimates the bispectrum when any side of the bispectrum triangle, $\ell_i<60$. However, the resulting changes in the reduced shear and magnification bias corrections are well below the sample variance for $\ell\leq5000$.

[33]  arXiv:2004.01695 [pdf, other]

Title: Molecular Gas Heating and Modified Dust Properties in Active Galaxies: Growing Black Holes or Tidal Shocks?

Authors: Rebecca Minsley, Andreea Petric, Erini Lambrides, Aleksandar M. Diadmond-Stanic, Maya Merhi, Marco Chiaberge, Nicolas Flagey

Comments: 10 pages, 3 figures, accepted to ApJ

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

We investigate if and how growing super-massive black holes (SMBH) known as Active Galactic Nuclei (AGN) and gravitational interactions affect the warm molecular gas and dust of galaxies. Our analysis focuses on the morphologies and warm ISM properties of 630 galaxies at z < 0.1. We use grizy images from the Pan-STARRS survey to classify the galaxies into mergers, early mergers, and non-mergers. We use MIR spectroscopic measurements of emission from rotational H2 transitions, dust and PAH features, and silicate emission or absorption lines at 9.7 microns to study how gravitational interactions impact the warm ISM in AGN and non-AGN hosts. We find that in AGN-hosts, the ISM is warmer, the ratios of H2 to PAHs are larger, the PAH emission line ratios and silicate strengths have a wider range of values than in non-AGN hosts. We find some statistical differences between the H2 emission of mergers and non-mergers, but those differences are less statistically significant than those between AGN and non-AGN hosts.

Cross-lists for Mon, 6 Apr 20

[34]  arXiv:2004.01042 (cross-list from gr-qc) [pdf, ps, other]

Title: Threshold of Primordial Black Hole Formation in Nonspherical Collapse

Authors: Chul-Moon Yoo, Tomohiro Harada, Hirotada Okawa

Comments: Two-column, 5 pages, 8 figures

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

We perform (3+1)-dimensional simulations of primordial black hole (PBH) formation starting from the spheroidal super-horizon perturbations. We investigate how the ellipticity (prolateness or oblateness) affects the threshold of PBH formation in terms of the peak amplitude of curvature perturbation. We find that, in the case of the radiation-dominated universe, the effect of ellipticity on the threshold is negligibly small for large amplitude of perturbations expected for PBH formation.

[35]  arXiv:2004.01193 (cross-list from hep-ph) [pdf, other]

Title: On the interplay between astrophysical and laboratory probes of MeV-scale axion-like particles

Authors: Fatih Ertas, Felix Kahlhoefer

Comments: 20 pages, 4 figures + appendices

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Experiment (hep-ex)

Studies of axion-like particles (ALPs) commonly focus on a single type of interaction, for example couplings only to photons. Most ALP models however predict correlations between different couplings, which change the phenomenology in important ways. For example, an MeV-scale ALP coupled to Standard Model gauge bosons at high energies will in general interact with photons, $W^\pm$ and $Z$ bosons as well as mesons and nucleons at low energies. We study the implications of such scenarios and point out that astrophysical constraints, in particular from SN1987A, may be substantially relaxed, opening up new regions of parameter space that may be explored with laboratory experiments such as NA62.

[36]  arXiv:2004.01199 (cross-list from hep-th) [pdf, other]

Title: Vacuum Arbitrariness and the Hubble Tension

Authors: Ali Kaya

Comments: 17 pages, 2 figures, to appear in Phys. Rev. D

Subjects: 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)

We show that the energy density of the superhorizon modes released in a non-Bunch-Davies vacuum can be arbitrarily large during inflation and it decreases like ln(a)/a^4 in the subsequent radiation dominated era. This may constitute a dark radiation component which can sufficiently alter the early cosmological evolution to alleviate the Hubble tension.

[37]  arXiv:2004.01233 (cross-list from gr-qc) [pdf, ps, other]

Title: On variations of $G$ in the geometric scalar theory of gravity

Authors: K.A. Bronnikov

Comments: 7 two-column pages, no figures

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

We analyze the possible variability of the effective Newtonian gravitational constant $G_{\rm N}$ in space and time in the framework of the geometric scalar theory of gravity suggested by M. Novello et al. [JCAP 06, 014 (2013); arXiv: 1212.0770]. Spatial variations of $G_{\rm N}$ in the Solar system are shown to have orders of magnitude detectable by modern instruments. As to variations of $G_{\rm N}$ with cosmological time, it is shown (at least for the particular formulation of the theory discussed in the original paper and the corresponding cosmological models) that these variations are more rapid than is allowed by observations.

[38]  arXiv:2004.01253 (cross-list from gr-qc) [pdf, other]

Title: Astrophysical and theoretical physics implications from multimessenger neutron star observations

Authors: Hector O. Silva, A. Miguel Holgado, Alejandro Cárdenas-Avendaño, Nicolás Yunes

Comments: 9 pages, 6 figures, 4 tables

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

The Neutron Star Interior Composition Explorer (NICER) recently measured the mass and equatorial radius of the isolated neutron star PSR J0030+0451. We use these measurements to infer the moment of inertia, the quadrupole moment, and the surface eccentricity of an isolated neutron star for the first time, using relations between these quantities that are insensitive to the unknown equation of state of supranuclear matter. We also use these results to forecast the moment of inertia of neutron star A in the double pulsar binary J0737-3039, a quantity anticipated to be directly measured in the coming decade with radio observations. Combining this information with the measurement of the tidal Love number with LIGO/Virgo observations, we propose and implement the first theory-agnostic and equation-of-state-insensitive test of general relativity. Specializing these constraints to a particular modified theory, we find that consistency with general relativity places the most stringent constraint on gravitational parity violation to date, surpassing all other previously reported bounds by seven orders of magnitude.

[39]  arXiv:2004.01400 (cross-list from physics.ins-det) [pdf, other]

Title: Control of a Filter Cavity with Coherent Control Sidebands

Authors: Naoki Aritomi, Matteo Leonardi, Eleonora Capocasa, Yuhang Zhao, Raffaele Flaminio

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

For broadband quantum noise reduction of gravitational wave detectors, frequency dependent squeezed vacuum states realized using a filter cavity is a mature technique and will be implemented in Advanced LIGO and Advanced Virgo from the fourth observation run. To obtain the benefit of frequency dependent squeezing, detuning and alignment of the filter cavity with respect to squeezed vacuum states must be controlled accurately. To this purpose we suggest a new length and alignment control scheme, using coherent control sidebands which are already used to control squeezing angle. Since both squeezed vacuum states and coherent control sidebands have the same mode matching conditions and almost the same frequency, detuning and alignment of the filter cavity can be controlled accurately with this scheme. In this paper, we show the principle of this scheme and its application to a gravitational-wave detector.

[40]  arXiv:2004.01440 (cross-list from gr-qc) [pdf, other]

Title: Rotating black holes without $\mathbb{Z}_2$ symmetry and their shadow images

Authors: Che-Yu Chen

Comments: 22 pages, 9 figures

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

The recent detection of gravitational waves from black hole coalescences and the first image of the black hole shadow enhance the possibilities of testing gravitational theories in the strong-field regime. In this paper, we study the physical properties and the shadow image of a class of Kerr-like rotating black holes, whose $\mathbb{Z}_2$ symmetry is generically broken. Such black hole solutions could arise in effective low-energy theories of a fundamental quantum theory of gravity, such as string theory. Within a theory-agnostic framework, we require that the Kerr-like solutions are asymptotically flat, and assume that a Carter-like constant is preserved, enabling the geodesic equations to be fully separable. Subject to these two requirements, we find that the $\mathbb{Z}_2$ asymmetry of the spacetime is characterized by two arbitrary functions of polar angle. The shadow image turns out to be $\mathbb{Z}_2$ symmetric on the celestial coordinates. Furthermore, the shadow is completely blind to one of the arbitrary functions. The other function, although would affect the apparent size of the shadow, it hardly distorts the shadow contour and has merely no degeneracy with the spin parameter. Therefore, the parameters in this function can be constrained with black hole shadows, only when the mass and the distance of the black hole from the earth are measured with great precision.

[41]  arXiv:2004.01470 (cross-list from hep-ph) [pdf, other]

Title: Could the Hubble Tension be Pointing Towards the Neutrino Mass Mechanism?

Authors: Miguel Escudero, Samuel J. Witte

Comments: 4 pages, 1 figure. Contribution to the NuPhys2019 proceedings: this https URL . Poster can be found at this https URL

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

Local measurements of the Hubble constant currently disagree with the high-precision value that is inferred from the CMB under the assumption of a $\Lambda$CDM cosmology. The significance of this tension clearly motivates studying extensions of the standard cosmological model capable of addressing this outstanding issue. Broadly speaking, models that have been successful in reducing the the tension between the CMB and local measurements (without introducing additional tension in other datasets) require an additional component of the energy density in the Universe at a time close to recombination.
In this contribution, I will show that the Majoron -- a pseudo-Goldstone boson arising from the spontaneous breaking of a global lepton number symmetry and often associated with the neutrino mass mechanism -- can help to reduce the Hubble tension. Importantly, I will also show that current CMB observations can constrain neutrino-Majoron couplings as small as $10^{-13}$, which within the type-I seesaw mechanism correspond to scales of lepton number breaking as high as $\sim 1\,\text{TeV}$.

[42]  arXiv:2004.01593 (cross-list from gr-qc) [pdf, ps, other]

Title: A Generalized Interacting Tsallis Holographic Dark Energy Model and its thermodynamic implications

Authors: Abdulla Al Mamon, Amir Hadi Ziaie, Kazuharu Bamba

Comments: 8 pages, 9 figures, Comments welcome

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

The paper deals with a theoretical model for interacting Tsallis holographic dark energy (THDE) whose infrared (IR) cut-off scale is set by the Hubble length. The interaction Q between the dark sectors (dark energy and pressureless dark matter) of the universe has been assumed to be non-gravitational in nature. The functional form of Q is chosen in such a way that it reproduces well known and most used interactions as special cases. We then study the nature of the THDE density parameter, the equation of state parameter, the deceleration parameter and the jerk parameter for this interacting THDE model. Our study shows that the universe undergoes a smooth transition from a decelerated to an accelerated phase of expansion in the recent past and also this transition occurs within the redshift interval [0.637,0.962]. This is well consistent with the present observations. It is shown the evolution of the the normalized Hubble parameter for our model and compared that with the latest Hubble parameter data. Finally, we also investigate both the stability and thermodynamic nature of this model in the present context.

[43]  arXiv:2004.01621 (cross-list from hep-ph) [pdf, other]

Title: Measuring the local Dark Matter density in the laboratory

Authors: Bradley J. Kavanagh, Timon Emken, Riccardo Catena

Comments: 5 pages, 3 figures. Monte Carlo and likelihood codes available at this https URL and this https URL respectively

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

Despite strong evidence for the existence of large amounts of dark matter (DM) in our Universe, there is no direct indication of its presence in our own solar system. All estimates of the local DM density, crucial for all direct DM searches, rely on extrapolating estimates on much larger scales. We demonstrate for the first time the possibility of measuring the local DM density with a direct detection experiment. It relies on the assumption that incoming DM particles frequently scatter on terrestrial nuclei prior to detection, inducing an additional time-dependence of the signal. We show that for sub-GeV DM, with a spin-independent DM-proton cross section $\sim10^{-32}\,\text{cm}^2$, future direct detection experiments should be able to reconstruct the local DM density with 20% uncertainty.

[44]  arXiv:2004.01642 (cross-list from hep-ph) [pdf, other]

Title: ALP Search Using a Fabry Perot Cavity

Authors: Richard Creswick, Frank T. Avignone III

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

In this paper we outline an experiment to detect the conversion of photons to axion-like particles (ALPs) in a strong magnetic field. We show that by modulating the polarization of the light passing through a Fabry-Perot cavity so that it effectively precesses at the modulation frequency, a signal is produced that is proportional to the square as opposed to the fourth power of the ALP-photon coupling constant. Assuming shot noise to be the dominant source of noise, we estimate that this approach is sensitive ALP masses less than $10^{-4} eV$ and couplings on the order to $g_{a\gamma}\sim 10^{-11} \text{GeV}^{-1}$ with a 10m, 10 T magnet, and $g_{a\gamma}\sim 10^{-12} \text{GeV}^{-1}$ with a 100 m magnet as envisaged by ALPs-IIc. ALPs with these properties have been invoked to explain the apparent transparency of the extragalactic background light (EBL) to ultra high-energy gamma rays emitted by BLAZARs.

[45]  arXiv:2004.01662 (cross-list from gr-qc) [pdf, other]

Title: Thin Accretion Disk around a four-dimensional Einstein-Gauss-Bonnet Black Hole

Authors: Cheng Liu, Tao Zhu, Qiang Wu

Comments: 7 pages, 5 figures

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

Recently a novel four dimensional Einstein-Gauss-Bonnet (4EGB) theory of gravity was proposed by Glavan and Lin [D. Glavan and C. Lin, Phys. Rev. Lett. 124, 081301 (2020)] which bypasses the Lovelock' s theorem with the re-scaling of the Gauss-Bonnet coupling constant $\alpha \to \alpha/(D-4)$ in the limit $D\to 4$. Here we study the physical properties of the electromagnetic radiation emitted from a thin accretion disk around the static spherically symmetric black hole in the 4EGB gravity. For this purpose, we assume the disk is in a steady-state and in hydrodynamic and thermodynamic equilibrium so that the emitted electromagnetic radiation is a black body spectrum. We study in detail the effects of the Gauss-Bonnet coupling constant $\alpha$ in 4EGB gravity on the energy flux, temperature distribution, and electromagnetic spectrum of the disk. It is shown that with the increases of the parameter $\alpha$, energy flux, temperature distribution, and electromagnetic spectrum of the disk all increases. In addition, we also show that the accretion efficiency decreases as the growing of the parameter $\alpha$. Our results indicate that the thin accretion disk around the 4EGB black hole is hotter, over luminosity, and more efficient than that around a Schwarzschild black hole with the same mass for a positive $\alpha$, while it is cooler, less luminosity, and less efficiency for a negative $\alpha$.

[46]  arXiv:2004.01676 (cross-list from physics.space-ph) [pdf, other]

Title: Dependence of kinetic plasma waves on ion-to-electron mass ratio and light-to-Alfvén speed ratio

Authors: Daniel Verscharen (UCL/MSSL, UNH), Tulasi N. Parashar (Victoria U), S. Peter Gary (SSI), Kristopher G. Klein (UA)

Comments: 8 pages, 8 figures. Accepted for publication in MNRAS

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

The magnetization $|\Omega_{\mathrm e}|/\omega_{\mathrm{e}}$ is an important parameter in plasma astrophysics, where $\Omega_{\mathrm e}$ and $\omega_{\mathrm{e}}$ are the electron gyro-frequency and electron plasma frequency, respectively. It only depends on the mass ratio $m_{\mathrm i}/m_{\mathrm e}$ and the light-to-Alfv\'en speed ratio $c/v_{\mathrm{Ai}}$, where $m_{\mathrm i}$ ($m_{\mathrm e}$) is the ion (electron) mass, $c$ is the speed of light, and $v_{\mathrm{Ai}}$ is the ion Alfv\'en speed. Nonlinear numerical plasma models such as particle-in-cell simulations must often assume unrealistic values for $m_{\mathrm i}/m_{\mathrm e}$ and for $c/v_{\mathrm{Ai}}$. Because linear theory yields exact results for parametric scalings of wave properties at small amplitudes, we use linear theory to investigate the dispersion relations of Alfv\'en/ion-cyclotron and fast-magnetosonic/whistler waves as prime examples for collective plasma behaviour depending on $m_{\mathrm i}/m_{\mathrm e}$ and $c/v_{\mathrm{Ai}}$. We analyse their dependence on $m_{\mathrm i}/m_{\mathrm e}$ and $c/v_{\mathrm{Ai}}$ in quasi-parallel and quasi-perpendicular directions of propagation with respect to the background magnetic field for a plasma with $\beta_j\sim1$, where $\beta_j$ is the ratio of the thermal to magnetic pressure for species $j$. Although their dispersion relations are largely independent of $c/v_{\mathrm{Ai}}$ for $c/v_{\mathrm{Ai}}\gtrsim 10$, the mass ratio $m_{\mathrm i}/m_{\mathrm e}$ has a strong effect at scales smaller than the ion inertial length. Moreover, we study the impact of relativistic electron effects on the dispersion relations. Based on our results, we recommend aiming for a more realistic value of $m_{\mathrm i}/m_{\mathrm e}$ than for a more realistic value of $c/v_{\mathrm{Ai}}$ in non-relativistic plasma simulations if such a choice is necessary, although $\dots$

Replacements for Mon, 6 Apr 20

[47]  arXiv:1409.6757 (replaced) [pdf, ps, other]

Title: A Generalization of Gravity

Authors: Chethan Krishnan

Comments: 7 pages, v2: minor typos fixed, refs added, v3: one more ref

Subjects: 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)

[48]  arXiv:1905.00870 (replaced) [pdf, ps, other]

Title: Fundamental physics implications on higher-curvature theories from the binary black hole signals in the LIGO-Virgo Catalog GWTC-1

Authors: Remya Nair, Scott Perkins, Hector O. Silva, Nicolás Yunes

Comments: v1: 6 pages, 1 figure. v2: matches published version. v3: errors corrected in Eq. (3) and Table I

Journal-ref: Phys. Rev. Lett. 123, 191101 (2019)

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

[49]  arXiv:1907.01580 (replaced) [pdf, other]

Title: Dark energy explained by an inadequate fitting of the FLRW metric

Authors: Vincent Deledicque

Comments: 12 pages, 1 figure

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

[50]  arXiv:1908.09670 (replaced) [pdf, ps, other]

Title: New general relativistic contributions to Mercury's orbital elements and their measurability

Authors: Lorenzo Iorio

Comments: LaTex2e, 14 pages, 1 figure, no tables. Accepted for publication in The European Physical Journal C

Subjects: General Relativity and Quantum Cosmology (gr-qc); Earth and Planetary Astrophysics (astro-ph.EP); Space Physics (physics.space-ph)

[51]  arXiv:1909.04044 (replaced) [pdf, other]

Title: A CMB Search for the Neutrino Mass Mechanism and its Relation to the $H_0$ Tension

Authors: Miguel Escudero, Samuel J. Witte

Comments: 5 pages, 2 figures + Supplementary Material. Comments are welcome! v2: Minor clarifications added. References added. Expanded Table 1 and moved it to the main text. Results and conclusions remain unchanged. Matches Letter published in EPJC. Ancillary file contains the obtained Planck legacy bound on neutrino-majoron interactions at 95%CL

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

[52]  arXiv:1910.00567 (replaced) [pdf, other]

Title: Probing Bosonic Stars with Atomic Clocks

Authors: Chris Kouvaris, Eleftherios Papantonopoulos, Lauren Street, L.C.R. Wijewardhana

Comments: 18 pages, 9 figures; discussion in Secs. 4 & 5 modified; constraints added & change in results reflected

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

[53]  arXiv:1910.04782 (replaced) [pdf, other]

Title: Explaining the AMS positron excess via Right-handed Neutrinos

Authors: Farinaldo S. Queiroz, Clarissa Siqueira

Comments: 9 pages, 10 figures; Accepted for publication in PRD

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

[54]  arXiv:1911.02632 (replaced) [pdf, other]

Title: Pions in hot dense matter and their astrophysical implications

Authors: Bryce Fore, Sanjay Reddy

Journal-ref: Phys. Rev. C, 2020

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

[55]  arXiv:1911.04505 (replaced) [pdf, other]

Title: The Schrödinger-Poisson method for Large-Scale Structure

Authors: Mathias Garny, Thomas Konstandin, Henrique Rubira

Comments: 29 pages, 17 figures. Published in JCAP

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

[56]  arXiv:1911.05337 (replaced) [pdf, other]

Title: Onset Mechanism of M6.5 Solar Flare Observed in Active Region 12371

Authors: Jihye Kang, Satoshi Inoue, Kanya Kusano, Sung-Hong Park, Yong-Jae Moon

Comments: 11 pages, 6 figures

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

[57]  arXiv:1912.00443 (replaced) [pdf, other]

Title: Constraints on Dark Matter from the Moon

Authors: Raghuveer Garani, Peter Tinyakov

Comments: 9 pages; v2: Improved moon models, updated references. Matches published version

Journal-ref: Phys.Lett. B804 (2020) 135403

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Earth and Planetary Astrophysics (astro-ph.EP); High Energy Astrophysical Phenomena (astro-ph.HE)

[58]  arXiv:1912.01919 (replaced) [pdf, ps, other]

Title: Superconformal generalizations of auxiliary vector modified polynomial f(R) theories

Authors: Sibel Boran, Emre Onur Kahya, Nese Ozdemir, Mehmet Ozkan, Utku Zorba

Comments: v3., title changed, various clarifications added, typos fixed, 8 pages, 2 figures, version appeared in JCAP

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

[59]  arXiv:1912.04008 (replaced) [pdf, other]

Title: Global fit of pseudo-Nambu-Goldstone Dark Matter

Authors: Chiara Arina, Ankit Beniwal, Céline Degrande, Jan Heisig, Andre Scaffidi

Comments: 35 pages, 10 figures, 2 tables; v2: Matches version published in JHEP

Journal-ref: JHEP04 (2020) 015

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

[60]  arXiv:1912.04149 (replaced) [pdf, other]

Title: Bounds on non-standard interactions of neutrinos from IceCube DeepCore data

Authors: S.V.Demidov

Comments: 13 pages, 9 figures, study of impact of the systematic uncertainties and improved comparison with experimental results added, bounds unchanged, references added, published version

Journal-ref: JHEP 03 (2020) 105

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

[61]  arXiv:1912.06681 (replaced) [pdf, other]

Title: Self-interacting dark matter without prejudice

Authors: Nicolás Bernal, Xiaoyong Chu, Suchita Kulkarni, Josef Pradler

Comments: Minor changes, to match the published version

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

[62]  arXiv:2002.02473 (replaced) [pdf, other]

Title: A Novel Survey for Young Substellar Objects with the W-band filter II. The Coolest and Lowest Mass Members of the Serpens-South Star-forming Region

Authors: Jessy Jose, Beth A. Biller, Loıc Albert, Sophie Dubber, Katelyn Allers, Gregory J. Herczeg, Michael C. Liu, Samuel Pearson, Bhavana Lalchand, Wen-Ping Chen, Mickael Bonnefoy, Etienne Artigau, Philippe Delorme, Po-shih Chiang, Zhoujian Zhang, Yumiko Oasa

Comments: Published in ApJ, 23 pages, 12 figures

Journal-ref: The Astrophysical Journal, 892:122 (11pp), 2020

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

[63]  arXiv:2002.10717 (replaced) [pdf, ps, other]

Title: ASASSN-16oh: A nova outburst with no mass ejection -- A new type of supersoft X-ray source in old populations

Authors: Mariko Kato, Hideyuki Saio, Izumi Hachisu

Comments: references updated, 21 pages, 10 figures, published in ApJ, 892, 15 (2020)

Journal-ref: ApJ, 892, 15 (2020)

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

[64]  arXiv:2003.06163 (replaced) [pdf, ps, other]

Title: High-resolution spectroscopy of flares and CMES on AD Leo*

Authors: Priscilla Muheki, Eike.W.Guenther, Tom Mutabazi, Edward Jurua

Comments: 10 pages, 7 figures, Accepted in A & A

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

[65]  arXiv:2003.07379 (replaced) [pdf, other]

Title: The Differences between Analytical and Numerical Ignition Curve of He-C-O Mixture

Authors: Rahul Kashyap

Comments: Comments are invited

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

[66]  arXiv:2003.11889 (replaced) [pdf, other]

Title: Side-On transition radiation detector: a detector prototype for TeV energy scale calibration of calorimeters in space

Authors: Bo Huang, Hongbang Liu, Xuefeng Huang, Ming Xu, Yongwei Dong, Xiaotong Wei, Xiwen Liu, Huanbo Feng, Qinhe Yang, Jianyu Gu, Shuai Chen, Xiaochuan Xie, Jin Zhang, Yongbo Huang, Enwei Liang

Comments: 13 pages, 10 figures, 2 tables

Journal-ref: Nuclear Inst. and Methods in Physics Research, A 962 (2020) 163723

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

[67]  arXiv:2003.13851 (replaced) [pdf, other]

Title: Differential rotation in neutron stars with open and closed magnetic topologies

Authors: F. Anzuini, A. Melatos

Comments: MNRAS accepted. 15 pages, 17 figures

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

[68]  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)

[69]  arXiv:2004.00634 (replaced) [pdf, other]

Title: Survey of Gravitationally-lensed Objects in HSC Imaging (SuGOHI). VI. Crowdsourced lens finding with Space Warps

Authors: Alessandro Sonnenfeld (1 and 2), Aprajita Verma (3), Anupreeta More (2 and 4), Campbell Allen (3), Elisabeth Baeten (5), James H. H. Chan (6), Roger Hutchings (3), Anton T. Jaelani (7 and 8), Chien-Hsiu Lee (9), Christine Macmillan (5), Philip J. Marshall (10), James O' Donnell (3), Masamune Oguri (2, 11 and 12), Cristian E. Rusu (13), Marten Veldthuis (3), Kenneth C. Wong (2 and 14), Claude Cornen (5), Christopher Davis (10), Adam McMaster (3), Laura Trouille (15), Chris Lintott (3), Grant Miller (3) ((1) Leiden Observatory, (2) Kavli IPMU, (3) University of Oxford, (4) IUCAA, (5) Zooniverse, (6) EPFL, (7) Kindai University, (8) Institut Teknologi Bandung, (9) NAOA, (10) KIPAC, (11) University of Tokyo, (12) Research Center for the Early Universe, (13) Subaru Telescope, (14) NAOJ, (15) Adler Planetarium)

Comments: Submitted to Astronomy & Astrophysics. 19 pages, 11 figures

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

[70]  arXiv:2004.01139 (replaced) [pdf, other]

Title: The Atacama Cosmology Telescope: A CMB lensing mass map over 2100 square degrees of sky and its cross-correlation with BOSS-CMASS galaxies

Authors: Omar Darwish, Mathew S. Madhavacheril, Blake Sherwin, Simone Aiola, Nicholas Battaglia, James A. Beall, Daniel T. Becker, J. Richard Bond, Erminia Calabrese, Steve Choi, Mark J. Devlin, Jo Dunkley, Rolando Dünner, Simone Ferraro, Anna E. Fox, Patricio A. Gallardo, Yilun Guan, Mark Halpern, Dongwon Han, Matthew Hasselfield, J. Colin Hill, Gene C. Hilton, Matt Hilton, Adam D. Hincks, Shuay-Pwu Patty Ho, J. Hubmayr, John P. Hughes, Brian J. Koopman, Arthur Kosowsky, J. Van Lanen, Thibaut Louis, Marius Lungu, Amanda MacInnis, Loïc Maurin, Jeffrey McMahon, Kavilan Moodley, Sigurd Naess, Toshiya Namikawa, Laura Newburgh, John P. Nibarger, Micheal D. Niemack, Lyman A. Page, Bruce Partridge, Frank J. Qu, Naomi Robertson, Benjamin Schmitt, Neelima Sehgal, Cristóbal Sifón, David N. Spergel, et al. (4 additional authors not shown)

Comments: 16 pages, 11 figures, lensing map products will be made available on LAMBDA as part of the upcoming ACT data release, v2 corrects author list

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

• New submissions
• Cross-lists
• Replacements