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New submissions for Thu, 13 Feb 20

[1]  arXiv:2002.04610 [pdf, other]

Title: A method for mapping the aliphatic hydrocarbon content of interstellar dust towards the Galactic Centre

Authors: B. Günay, M. G. Burton, M. Afşar, T. W. Schmidt

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

In the interstellar medium, the cosmic elemental carbon abundance includes the total carbon in both gas and solid phases. The aim of the study was to trial a new method for measuring the amount and distribution of aliphatic carbon within interstellar dust over wide fields of view of our Galaxy. This method is based on measurement of the 3.4 $\mu$m absorption feature from aliphatic carbonaceous matter. This can readily be achieved for single sources using IR spectrometers. However, making such measurements over wide fields requires an imaging IR camera, equipped with narrow-band filters that are able to sample the spectrum. While this cannot produce as good a determination of the spectra, the technique can be applied to potentially tens to hundreds of sources simultaneously, over the field of view of the camera. We examined this method for a field in the centre of the Galaxy, and produced a map showing the variation of 3.4 $\mu$m optical depth across it.

[2]  arXiv:2002.04614 [pdf, other]

Title: Polarization constraints on the geometry of the magnetic field in the external shock of gamma-ray bursts

Authors: Eric Stringer, Davide Lazzati (Oregon State University)

Comments: 6 pages, submitted to AAS journals

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

We study the ensemble of linear polarization measurement in the optical afterglows of long-duration gamma-ray bursts. We assume a non sideways-expanding top-hat jet geometry and use the relatively large number of measurements under the assumption that they represent a statistically unbiased sample. This allows us to constrain the ratio between the maximum predicted polarization and the measured one, which is an indicator of the geometry of the magnetic field in the downstream region of the external shock. We find that the measured polarization is substantially suppressed with respect to the maximum possible for either a completely ordered magnetic field parallel to the shock normal or to a field that is entirely contained in the shock plane. The measured polarization is limited, on average, to between 25 and 30% of the maximum theoretically possible value. This reduction requires the perpendicular component of the magnetic field to be dominant in energy with respect to the component parallel to the shock front, as expected for a shock generated and/or shock compressed field. We find, however, that the data only marginally support the assumption of a simple top-hat jet, pointing towards a more complex geometry for the outflow.

[3]  arXiv:2002.04618 [pdf, ps, other]

Title: Multiwavelength Follow-up of the Hyperluminous Intermediate-mass Black Hole Candidate 3XMM J215022.4-055108

Authors: Dacheng Lin, Jay Strader, Aaron J. Romanowsky, Jimmy A. Irwin, Olivier Godet, Didier Barret, Natalie A. Webb, Jeroen Homan, Ronald A. Remillard

Comments: Accepted for publication in ApJL, 5 pages, 4 figures

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

We recently discovered the X-ray/optical outbursting source 3XMM J215022.4-055108. It was best explained as the tidal disruption of a star by an intermediate-mass black hole of mass of a few tens of thousand solar masses in a massive star cluster at the outskirts of a large barred lenticular galaxy at D_L=247 Mpc. However, we could not completely rule out a Galactic cooling neutron star as an alternative explanation for the source. In order to further pin down the nature of the source, we have obtained new multiwavelength observations by XMM-Newton and Hubble Space Telescope (HST). The optical counterpart to the source in the new HST image is marginally resolved, which rules out the Galactic cooling neutron star explanation for the source and suggests a star cluster of half-light radius ~27 pc. The new XMM-Newton observation indicates that the luminosity was decaying as expected for a tidal disruption event and that the disk was still in the thermal state with a super-soft X-ray spectrum. Therefore, the new observations confirm the source as one of the best intermediate-mass black hole candidates.

[4]  arXiv:2002.04621 [pdf, other]

Title: Dynamical friction-driven orbital circularisation in rotating discs: a semi-analytical description

Authors: Matteo Bonetti, Elisa Bortolas, Alessandro Lupi, Massimo Dotti, Sandra I. Raimundo

Comments: 7 pages, 3 figures, submitted to MNRAS

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

We present and validate a novel semi-analytical approach to study the effect of dynamical friction on the orbits of massive perturbers in rotating stellar discs. We find that dynamical friction efficiently circularises the orbit of co-rotating perturbers, while it constantly increases the eccentricity of counter-rotating ones until their angular momenta reverse, then once again promoting circularisation. Such "drag toward circular corotation" could shape the distribution of orientations of kinematically decoupled cores in disc galaxies, naturally leading to the observed larger fraction of co-rotating cores.

[5]  arXiv:2002.04622 [pdf, other]

Title: Keeping it Cool: Much Orbit Migration, yet Little Heating, in the Galactic Disk

Authors: Neige Frankel, Jason Sanders, Yuan-Sen Ting, Hans-Walter Rix

Comments: Submitted to ApJ, comments are welcome

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

A star in the Milky Way's disk can now be at a Galactocentric radius quite distant from its birth radius for two reasons: either its orbit has become eccentric through radial heating, which increases its radial action $J_R$ (`blurring'); or merely its angular momentum $L_z$ has changed and thereby its guiding radius (`churning'). We know that radial orbit migration is strong in the Galactic low-$\alpha$ disk and set out to quantify the relative importance of these two effects, by devising and applying a parameterized model for the distribution $p(L_z, J_R, \tau, \mathrm[Fe/H])$ in the stellar disk. This model describes the orbit evolution for stars of age $\tau$ and metallicity [Fe/H], presuming coeval stars were initially born on (near-)circular orbits, and with a unique [Fe/H] at a given birth angular momentum and age. We fit this model to APOGEE red clump stars, accounting for the complex selection function of the survey. The best fit model implies changes of angular momentum of $\sqrt{\langle \Delta L_z \rangle^2} \approx 619\, \mathrm{kpc~km/s~}(\tau/\mathrm{6~Gyr})^{0.5}$, and changes of radial action as $\sqrt{\langle \Delta J_R \rangle^2} \approx 63\, \mathrm{kpc~km/s~} (\tau/\mathrm{6~Gyr})^{0.6}$ at 8 kpc. This suggests that the secular orbit evolution of the disk is dominated by diffusion in angular momentum, with radial heating being an order of magnitude lower.

[6]  arXiv:2002.04625 [pdf, other]

Title: Dynamics of millicharged dark matter in supernova remnants

Authors: Jung-Tsung Li, Tongyan Lin

Comments: 38 pages, 13 figures

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

Dark matter could have a small electromagnetic charge, provided the charge-to-mass ratio is much less than that of electrons or protons. This candidate, commonly known as millicharged dark matter (mDM), would form a plasma and interact with the interstellar medium and electromagnetic fields within galaxies. In general, understanding the dynamics of mDM requires consideration of collective plasma effects. It has been proposed that mDM can be accelerated in supernova remnants, forming a dark cosmic ray population that would leave distinct experimental signatures. In this work, we study a microphysical model where mDM is shocked by a supernova remnant and isotropized in the frame of the expanding fluid. We find that for $|q_\chi/m_\chi| \gtrsim 10^{-13} e / {\rm MeV}$, the isotropization length for electromagnetic plasma instabilities is much shorter than the size of the supernova remnant. This is a necessary, though not sufficient, first step for formation of a Fermi-accelerated mDM component, and determining the size of this component requires further study. We discuss additional implications of mDM interactions in supernova remnants.

[7]  arXiv:2002.04633 [pdf, other]

Title: Sun-like Stars Shed Light on Solar Climate Forcing

Authors: P. G. Judge, R. Egeland, G. W. Henry

Comments: 6 pages, 6 figures, accepted to The Astrophysical Journal Letters

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

Recently published, precise stellar photometry of 72 Sun-like stars obtained at the Fairborn Observatory between 1993 and 2017 is used to set limits on the solar forcing of Earth's atmosphere of $\pm$ 4.5 W m$^{-2}$ since 1750. This compares with the +2.2 $\pm$ 1.1 W m$^{-2}$ IPCC estimate for anthropogenic forcing. Three critical assumptions are made. In decreasing order of importance they are: (a) most of the brightness variations occur within the average time-series length of $\approx$17 years; (b) the Sun seen from the ecliptic behaves as an ensemble of middle-aged solar-like stars; and (c) narrow-band photometry in the Str\"omgren $b$ and $y$ bands are linearly proportional to the total solar irradiance. Assumption (a) can best be relaxed and tested by obtaining more photometric data of Sun-like stars, especially those already observed. Eight stars with near-solar parameters have been observed from 1999, and two since 1993. Our work reveals the importance of continuing and expanding ground-based photometry, to complement expensive solar irradiance measurements from space.

[8]  arXiv:2002.04635 [pdf, other]

Title: hybrid-Lenstool: A self-consistent algorithm to model galaxy clusters with strong- and weak-lensing simultaneously

Authors: Anna Niemiec, Mathilde Jauzac, Eric Jullo, Marceau Limousin, Keren Sharon, Jean-Paul Kneib, Priyamvada Natarajan, Johan Richard

Comments: 11 pages, 4 figures, 1 table

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

We present a new galaxy cluster lens modeling approach, hybrid-Lenstool, that is implemented in the publicly available modeling software Lenstool. hybrid-Lenstool combines a parametric approach to model the core of the cluster, and a non-parametric (free-form) approach to model the outskirts. hybrid-Lenstool optimizes both strong- and weak-lensing constraints simultaneously (Joint-Fit), providing a self-consistent reconstruction of the cluster mass distribution on all scales. In order to demonstrate the capabilities of the new algorithm, we tested it on a simulated cluster. hybrid-Lenstool yields more accurate reconstructed mass distributions than the former Sequential-Fit approach where the parametric and the non-parametric models are optimized successively. Indeed, we show with the simulated cluster that the mass density profile reconstructed with a Sequential-Fit deviates form the input by $2-3\sigma$ at all scales while the Joint-Fit gives a profile that is within $1-1.5\sigma$ of the true value. This gain in accuracy is consequential for recovering mass distributions exploiting cluster lensing and therefore for all applications of clusters as cosmological probes. Finally we found that the Joint-Fit approach yields shallower slope of the inner density profile than the Sequential-Fit approach, thus revealing possible biases in previous lensing studies.

[9]  arXiv:2002.04645 [pdf, other]

Title: YZiCS: Unveiling Quenching History of Cluster Galaxies Using Phase-space Analysis

Authors: Jinsu Rhee, Rory Smith, Hoseung Choi, Emanuele Contini, S. Lyla Jung, San Han, Sukyoung K. Yi

Comments: 24 pages, 11 figures, 1 table, accepted to ApJS

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

We used the time since infall (TSI) of galaxies, obtained from the Yonsei Zoom-in Cluster Simulation, and the star formation rate (SFR) from the Sloan Digital Sky Survey (SDSS) Data Release 10 to study how quickly star formation of disk galaxies is quenched in cluster environments. We first confirm that both simulated and observed galaxies are consistently distributed in phase space. We then hypothesize that the TSI and SFR are causally connected; thus, both the TSI and SFR of galaxies at each position of phase space can be associated through abundance matching. Using a flexible model, we derive the star formation history (SFH) of cluster galaxies that best reproduces the relationship between the TSI and SFR at $z\sim 0.08$. According to this SFH, we find that the galaxies with $M_{*} > 10^{9.5} M_{\odot}$ generally follow the so-called "delayed-then-rapid" quenching pattern. Our main results are as following: (i) Part of the quenching takes place outside clusters through mass quenching and pre-processing. The e-folding timescale of this "$ex\text{-}situ$ quenching phase" is roughly 3 Gyr with a strong inverse mass dependence. (ii) The pace of quenching is maintained roughly for 2 Gyr ("delay time") during the first crossing time into the cluster. During the delay time, quenching remains gentle probably because gas loss happens primarily on hot and neutral gases. (iii) Quenching becomes more dramatic (e-folding timescale of roughly 1 Gyr) after delay time, probably because ram pressure stripping is strongest near the cluster center. Counter-intuitively, more massive galaxies show shorter quenching timescales mainly because they enter their clusters with lower gas fractions due to $ex\text{-}situ$ quenching.

[10]  arXiv:2002.04646 [pdf, other]

Title: Short-term variability and mass loss in Be stars V. Space photometry and ground-based spectroscopy of $γ$ Cas

Authors: Camilla C. Borre, Dietrich Baade, Andrzej Pigulski, Despina Panoglou, Achim Weiss, Thomas Rivinius, Gerald Handler, Anthony F. J. Moffat, Adam Popowicz, Gregg A. Wade, Werner W. Weiss, Konstanze Zwintz

Comments: 13 pages, 12 figures. Accepted for publication in A&A

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

Context. Be stars are physically complex systems that continue to challenge theory to understand their rapid rotation, complex variability and decretion disks. $\gamma$ Cassiopeiae ($\gamma$ Cas) is one such star but is even more curious because of its unexplained hard thermal X-ray emission. Aims. We aim to examine the optical variability of $\gamma$ Cas and thereby to shed more light on its puzzling behaviour. Methods. Three hundred twenty-one archival H$\alpha$ spectra from 2006 to 2017 are analysed to search for frequencies corresponding to the 203.5 day orbit of the companion. Space photometry from the SMEI satellite from 2003 to 2011 and the BRITE-Constellation of nano-satellites between 2015 and 2019 is investigated in the period range from a couple of hours to a few days. Results. The orbital period of the companion of 203.5 days is confirmed with independent measurements from the structure of the H$\alpha$ line emission. A strong blue/red asymmetry in the amplitude distribution across the H$\alpha$ emission line could hint at a spiral structure in the decretion disk. With the space photometry, the known frequency of 0.82 d$^{-1}$ is confirmed in data from the early 2000s. A higher frequency of 2.48 d$^{-1}$ is present in the data from 2015 to 2019 and possibly also in the early 2000s. A third frequency at 1.25 d$^{-1}$ is proposed to exist in both SMEI and BRITE data. The only explanation covering all three rapid variations seems to be nonradial pulsation. The two higher frequencies are incompatible with rotation.

[11]  arXiv:2002.04649 [pdf, other]

Title: Effects of Mirror Seeing on High-Contrast Adaptive Optics Instruments

Authors: Melisa Tallis, Vanessa P. Bailey, Bruce Macintosh, Lisa A. Poyneer, Jean-Baptiste Ruffio, Thomas L. Hayward, Fredrik T. Rantakyrö, Jeffrey K. Chilcote, Dmitry Savransky

Journal-ref: J. Astron. Telesc. Instrum. Syst. 6(1), 015002 (2020)

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

Ground-based direct imaging surveys like the Gemini Planet Imager Exoplanet Survey (GPIES) rely on Adaptive Optics (AO) systems to image and characterize exoplanets that are up to a million times fainter than their host stars. One factor that can reduce AO performance is turbulence induced by temperature differences in the instrument's immediate surroundings (e.g.: "dome seeing" or "mirror seeing"). In this analysis we use science observations, AO telemetry, and environmental data from September 2014 to February 2017 of the GPIES campaign to quantify the effects of "mirror seeing" on the performance of the GPI instrument. We show that GPI performance is optimal when the primary mirror (M1) is in equilibrium with the outside air temperature. We then examine the characteristics of mirror seeing by calculating the power spectral densities (PSD) of spatial and temporal Fourier modes. Inside the inertial range of the PSDs, we find that the spatial PSD amplitude increases when M1 is out of equilibrium and that the integrated turbulence may exhibit deviations from Kolmogorov atmospheric turbulence models and from the 1-layer frozen flow model. We conclude with an assessment of the current temperature control and ventilation strategy at Gemini South.

[12]  arXiv:2002.04651 [pdf, other]

Title: Chemistry Along Accretion Streams in a Viscously-Evolving Protoplanetary Disk

Authors: Ellen M. Price, L. Ilsedore Cleeves, Karin I. Öberg

Comments: Accepted for publication in ApJ

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

The composition of a protoplanetary disk is set by a combination of interstellar inheritance and gas and grain surface chemical reactions within the disk. The survival of inherited molecules, as well as the disk in situ chemistry depends on the local temperature, density and irradiation environment, which can change over time due to stellar and disk evolution, as well as transport in the disk. We address one aspect of this coupling between the physical and chemical evolution in disks by following accretion streamlines of gas and small grains in the disk midplane, while simultaneously taking the evolving star into account. This approach is computationally efficient and enables us to take into account changing physical conditions without reducing the chemical network. We find that many species are enhanced in the inner disk midplane in the dynamic model due to inward transport of cosmic-ray driven chemical products, resulting in, e.g., orders-of magnitude hydrocarbon enhancements at 1 au, compared to a static disk. For several other chemical families, there is no difference between the static and dynamic models, indicative of a robust chemical reset, while yet others show differences between static and dynamic models that depend on complex interactions between physics and chemistry during the inward track. The importance of coupling dynamics and chemistry when modeling the chemical evolution of protoplanetary disks is thus depends on what chemistry is of interest.

[13]  arXiv:2002.04652 [pdf, ps, other]

Title: Two fundamental constraints on the inner radii of accretion disks

Authors: Andrzej A. Zdziarski, Barbara De Marco

Comments: submitted to ApJ, comments are welcome

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

We have derived a method yielding very strong constraints on the inner radii of accretion disks in black-hole X-ray binaries based on the Stefan-Boltzmann law. It follows from considering the irradiating flux and the effective temperature of inner parts of the disk. Then, the presence of a quasi-thermal component with a color temperature higher than the effective one is required whenever Fe K fluorescence and reflection features are observed. The observed absence of such quasi-thermal components with the color temperature of $\sim$1 keV rules out a disk extending close to the innermost stable circular orbit in high-luminosity hard states and requires it to be truncated, favoring the presence of a hot flow inside the disk truncation radius in those states. We have also derived a method based on comparing the disk densities fitted (by other authors) using high-density reflection codes with those calculated by us from the fitted ionization parameter, the source luminosity and the disk inner radius. However, we have found a very large scatter of the density ratios, preventing us from obtaining significant constraints as yet.

[14]  arXiv:2002.04669 [pdf, ps, other]

Title: Spectroscopy of hot Gamma Doradus and A-F hybrid Kepler candidates close to the hot border of the Delta Scuti instability strip

Authors: F. Kahraman Alicavus, E. Poretti, G. Catanzaro, B. Smalley, E. Niemczura, M. Rainer, G. Handler

Comments: Accepted for publication in Monthly Notices of the Royal Astronomical Society Letters

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

If Gamma Dor-type pulsations are driven by the convective blocking mechanism, a convective envelope at a sufficient depth is essential. There are several hot Gamma Dor and hybrid star candidates in which there should not be an adequate convective envelope to excite the{\gamma}Dor-type oscillations. The existence of these hot objects needs an explanation. Therefore, we selected, observed and studied 24 hot{\gamma}Dor and hybrid candidates to investigate their properties. The atmospheric parameters, chemical abundances and vsini values of the candidates were obtained using medium-resolution (R= 46 000)spectra taken with the FIES instrument mounted at the NordicOptical Telescope. We also carried out frequency analyses of theKeplerlong- and short-cadence data to determine the exact pulsation contents. We found only five bona-fide hot{\gamma}Dor and three bona-fide hot hybrid stars in our sample. The other 16 stars were found to benormal{\gamma}Dor,{\delta}Sct, or hybrid variables. No chemical peculiarity was detected in the spectra of the bona-fide hot{\gamma}Dor and hybrid stars. We investigated the interplay between rotation and pulsational modes. We also found that the hot{\gamma}Dor stars havehigherGaialuminosities and larger radii compared to main-sequence A-F stars.

[15]  arXiv:2002.04740 [pdf, other]

Title: The role of gravitational recoil in the assembly of massive black hole seeds

Authors: Glenna Dunn, Kelly Holley-Bockelmann, Jillian Bellovary

Comments: 8 pages, 6 figures. Submitted to ApJ

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

When two black holes merge, the asymmetric emission of gravitational waves provides an impulse to the merged system; this gravitational wave recoil velocity can be up to 4000 km s$^{-1}$, easily fast enough for the black hole to escape its host galaxy. We combine semi-analytic modeling with cosmological zoom-in simulations of a Milky Way-type galaxy to investigate the role of black hole spin and gravitational recoil in the epoch of massive black hole seeding. We sample four different spin distributions (random, aligned, anti-aligned, and zero spin), and compare the resulting merger rates, occupation fractions, and MBH-host relations with what is expected by excluding the effect of recoil. The inclusion of gravitational recoil and MBH spin in the assembly of MBH seeds can reduce the final $z=5$ MBH mass by up to an order of magnitude. The MBH occupation fraction, however, remains effectively unaltered due to episodes of black hole formation following a recoil event. While electromagnetic detections of these events are unlikely, LISA is ideally suited to detect gravitational wave signals from such events.

[16]  arXiv:2002.04748 [pdf, other]

Title: A Systematic Study of the dust of Galactic Supernova Remnants I. The Distance and the Extinction

Authors: He Zhao, Biwei Jiang, Jun Li, Bingqiu Chen, Bin Yu, Ye Wang

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

By combining the photometric, spectroscopic, and astrometric information of the stars in the sightline of SNRs, the distances to and the extinctions of 32 Galactic supernova remnants (SNRs) are investigated. The stellar atmospheric parameters are from the SDSS$-$DR14$/$APOGEE and LAMOST$-$DR5$/$LEGUE spectroscopic surveys. The multi-band photometry, from optical to infrared, are collected from the {\it Gaia}, APASS, Pan--STARRS1, 2MASS, and {\it WISE} surveys. With the calibrated {\it Gaia} distances of individual stars, the distances to 15 of 32 SNRs are well determined from their produced extinction and association with molecular clouds. The upper limits of distance are derived for 3 SNRs. The color excess ratios $E(\gps-\lambda) / E(\gps-\rps)$ of 32 SNRs are calculated, and their variation with wavebands is fitted by a simple dust model. The inferred dust grain size distribution bifurcates: while the graphite grains have comparable size to the average ISM dust, the silicate grains are generally larger. Along the way, the average extinction law from optical to near-infrared of the Milky Way is derived from the 1.3 million star sample and found to agree with the CCM89 law with $\Rv=3.15$.

[17]  arXiv:2002.04749 [pdf, other]

Title: Production of Lithium in Primordial Supernovae

Authors: Alexander Heger (1), Stan Woosley (2) ((1) School of Physics and Astronomy, Monash University, Australia, (2) Department of Astronomy and Astrophysics, University of California at Santa Cruz, USA)

Comments: 5 pages, 8 figures, Proc. "Lithium in the Universe: to Be or not to Be"

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

The first generation of stars is quite unique. The absence of metals likely affects their formation, with current models suggesting a much more top-heavy initial mass fraction than what we observe today, and some of their other properties, such as rotation rates and binarity, are largely unknown or constrained by direct observations. But even non-rotation single stars of a given mass will evolve quite differently due to the absence of the metals: the stars will mostly remain much more compact until their death, with the hydrogen-rich later reaching down ten teems deeper in radius then in modern stars. When they explode as supernovae, the exposure to the supernova neutrino flux is much enhanced, allowing for copious production of lithium. This production will not be constant for all stars but largely vary across the mass range. Such production even more challenges the presence of the Spite Plateau.

[18]  arXiv:2002.04751 [pdf, ps, other]

Title: Asteroid belt survival through stellar evolution: dependence on the stellar mass

Authors: Rebecca G. Martin, Mario Livio, Jeremy L. Smallwood, Cheng Chen

Comments: Accepted for publication in MNRAS Letters

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

Polluted white dwarfs are generally accreting terrestrial-like material that may originate from a debris belt like the asteroid belt in the solar system. The fraction of white dwarfs that are polluted drops off significantly for white dwarfs with masses $M_{\rm WD}\gtrsim 0.8\,\rm M_\odot$. This implies that asteroid belts and planetary systems around main-sequence stars with mass $M_{\rm MS}\gtrsim 3\,\rm M_\odot$ may not form because of the intense radiation from the star. This is in agreement with current debris disc and exoplanet observations. The fraction of white dwarfs that show pollution also drops off significantly for low mass white dwarfs $(M_{\rm WD}\lesssim 0.55\,\rm M_\odot)$. However, the low-mass white dwarfs that do show pollution are not currently accreting but have accreted in the past. We suggest that asteroid belts around main sequence stars with masses $M_{\rm MS}\lesssim 2\,\rm M_\odot$ are not likely to survive the stellar evolution process. The destruction likely occurs during the AGB phase and could be the result of interactions of the asteroids with the stellar wind, the high radiation or, for the lowest mass stars that have an unusually close-in asteroid belt, scattering during the tidal orbital decay of the inner planetary system.

[19]  arXiv:2002.04762 [pdf, other]

Title: {\sc precision}: A fast python pipeline for high-contrast imaging -- application to SPHERE observations of the red supergiant VX Sagitariae

Authors: P. Scicluna, F. Kemper, R. Siebenmorgen, R. Wesson, J.A.D.L. Blommaert, S. Wolf

Comments: 13 pages, 5 figures. Accepted by MNRAS

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 search for extrasolar planets has driven rapid advances in instrumentation, resulting in cameras such as SPHERE at the VLT, GPI at Gemini South and SCExAO at Subaru, capable of achieving very high contrast ($\sim10^{6}$) around bright stars with small inner working angles ($\sim 0\farcs{1}$). The optimal exploitation of data from these instruments depends on the availability of easy-to-use software to process and analyse their data products. We present a pure-python pipeline, {\sc precision}, which provides fast, memory-efficient reduction of data from the SPHERE/IRDIS near-infrared imager, and can be readily extended to other instruments. We apply {\sc precision} to observations of the extreme red supergiant VX~Sgr, the inner outflow of which is revealed to host complex, asymmetric structure in the near-IR. In addition, optical polarimetric imaging reveals clear extended polarised emission on $\sim0.5^{\prime\prime}$ scales which varies significantly with azimuth, confirming the asymmetry. While not conclusive, this could suggest that the ejecta are confined to a disc or torus, which we are viewing nearly face on, although other non-spherical or clumpy configurations remain possible. VX~Sgr has no known companions, making such a geometry difficult to explain, as there is no obvious source of angular momentum in the system.

[20]  arXiv:2002.04798 [pdf, other]

Title: The TRAPPIST-1 JWST Community Initiative

Authors: Michaël Gillon, Victoria Meadows, Eric Agol, Adam J. Burgasser, Drake Deming, René Doyon, Jonathan Fortney, Laura Kreidberg, James Owen, Franck Selsis, Julien de Wit, Jacob Lustig-Yaeger, Benjamin V. Rackham

Comments: Comments and suggestions are welcome and can be addressed to t1jwstci_board@u.washington.edu. 23 pages, 8 figures

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

The upcoming launch of the James Webb Space Telescope (JWST) combined with the unique features of the TRAPPIST-1 planetary system should enable the young field of exoplanetology to enter into the realm of temperate Earth-sized worlds. Indeed, the proximity of the system (12pc) and the small size (0.12 Rsun) and luminosity (0.05 Lsun) of its host star should make the comparative atmospheric characterization of its seven transiting planets within reach of an ambitious JWST program. Given the limited lifetime of JWST, the ecliptic location of the star that limits its visibility to 100d per year, the large number of observational time required by this study, and the numerous observational and theoretical challenges awaiting it, its full success will critically depend on a large level of coordination between the involved teams and on the support of a large community. In this context, we present here a community initiative aiming to develop a well-defined sequential structure for the study of the system with JWST and to coordinate on every aspect of its preparation and implementation, both on the observational (e.g. study of the instrumental limitations, data analysis techniques, complementary space-based and ground-based observations) and theoretical levels (e.g. model developments and comparison, retrieval techniques, inferences). Depending on the outcome of the first phase of JWST observations of the planets, this initiative could become the seed of a major JWST Legacy Program devoted to the study of TRAPPIST-1.

[21]  arXiv:2002.04801 [pdf, other]

Title: Analysis of membership probability in nearby young moving groups with Gaia DR2

Authors: K. Ujjwal, Sreeja S. Kartha, Blesson Mathew, P. Manoj, Mayank Narang

Comments: 14 Pages, 5 Figures, 4 Tables, Accepted for publication in AJ

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

We analyze the membership probability of young stars belonging to nearby moving groups with $\textit{Gaia}$ DR2 data. The sample of 1429 stars were identified from 'The Catalog of Suspected Nearby Young Moving Group Stars'. Good-quality parallax and proper motion values were retrieved for 890 stars from $\textit{Gaia}$ DR2 database. The analysis for membership probability is performed in the framework of LACEwING algorithm. From the analysis it is confirmed that 279 stars do not belong to any of the known moving groups. We estimated the $\textit{ U, V, W}$ space velocity values for 250 moving group members, which were found to be more accurate than previous values listed in the literature. The velocity ellipses of all the moving groups are well constrained within the "good box", a widely used criterion to identify moving group members. The age of moving group members are uniformly estimated from the analysis of $\textit{Gaia}$ Color-Magnitude Diagram with MIST isochrones. We found a spread in the age distribution of stars belonging to some moving groups, which needs to be understood from further studies.

[22]  arXiv:2002.04816 [pdf, ps, other]

Title: ALMA Imaging of the CO(7-6) Line Emission in the Submillimeter Galaxy LESS 073 at redshift 4.755$^\star$

Authors: Yinghe Zhao, Nanyao Lu, Tanio Díaz-Santos, Yu Gao, C. Kevin Xu, Vassilis Charmandaris, Hanae Inami, Dimitra Rigopoulou, David B. Sanders, Jiasheng Huang, Zhong Wang

Comments: 8 pages, 6 figures, accepted for publication in ApJ

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

In this paper we present our imaging observations on the CO(7-6) line and its underlying continuum emission of the young submillimeter galaxy LESS 073 at redshift 4.755, using the Atacama Large Millimeter/submillimeter Array (ALMA). At the achieved resolution of $\sim$$1^{\prime\prime}.2\times0^{\prime\prime}.9$ ($8\times6$~kpc$^2$), the CO(7-6) emission is largely unresolved (with a deconvolved size of $1^{\prime\prime}.1(\pm0^{\prime\prime}.5) \times 0^{\prime\prime}.9(\pm0^{\prime\prime}.8)$), and the continuum emission is totally unresolved. The CO(7-6) line emission has an integrated flux of $0.86\pm0.08$~Jy km/s, and a line width of $343\pm40$ km/s. The continuum emission has a flux density of 0.51 mJy. By fitting the observed far-infrared (FIR) spectral energy distribution of LESS 073 with a single-temperature modified blackbody function, we obtained a dust temperature $T_{\rm dust}=57.6\pm3.5$ K, 60-to-100 $\mu$m flux density ratio $f_{60}/f_{100}=0.86\pm0.08$, and total infrared luminosity $L_{\rm IR}=(5.8\pm0.9) \times 10^{12}~L_\odot$. The SED-fit-based $f_{60}/f_{100}$ is consistent with those estimated from various line ratios as advocated by our earlier work, indicating that those proposed line-ratio-based method can be used to practically derive $f_{60}/f_{100}$ for high-$z$ sources. The total molecular gas mass of LESS 073 is $(3.3\pm1.7) \times10^{10}~M_\odot$, and the inferred gas depletion time is about 43 Myr.

[23]  arXiv:2002.04817 [pdf, ps, other]

Title: The 21-cm signals from ultracompact minihalos as a probe of primordial small-scale fluctuations

Authors: Kunihiko Furugori, Katsuya Abe, Toshiyuki Tanaka, Daiki Hashimoto, Hiroyuki Tashiro, Kenji Hasegawa

Comments: 8pages, 6 figures, submitted to MNRAS

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

Ultracompact minihalos~(UCMHs) can form after the epoch of matter-radiation equality, if the density fluctuations of dark matter have significantly large amplitude on small scales. The constraint on the UCMH abundance allows us to access such small-scale fluctuations. In this paper, we present that, through the measurement of 21-cm fluctuations before the epoch of reionization~ we can obtain a constraint on the UCMH abundance. We calculate the 21-cm signal from UCMHs and show that UCMHs provide the enhancement of the 21-cm fluctuations. We also investigate the constraint on the UCMH abundance and small-scale curvature perturbations. Our results indicate that the upcoming 21-cm observation, the Square Kilometre Array (SKA), provides the constraint on amplitude of primordial curvature power spectrum, ${\cal A}_{\zeta} \lesssim 10^{-6}$ on $100~{\rm Mpc}^{-1} \lesssim k \lesssim 1000~{\rm Mpc}^{-1}$. Although it is not stronger than the one from the non-detection of gamma rays induced by dark matter annihilation in UCMHs, the constraint by the SKA will be important because this constraint is independent of the dark matter particle model.

[24]  arXiv:2002.04819 [pdf, other]

Title: Prospects for a Multi-TeV Gamma-ray Sky Survey with the LHAASO Water Cherenkov Detector Array

Authors: Yingying Guo, Xiaochuan Chang, Hongbo Hu, Zhiguo Yao

Comments: 10 pages,10 figures, it is to be published in Chinese Physics C

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

The Water Cherenkov Detector Array (WCDA) is a major component of the Large High Altitude Air Shower Array Observatory (LHAASO), a new generation cosmic-ray experiment with unprecedented sensitivity, currently under construction. The WCDA is aimed at the study of TeV $\gamma$-rays. In order to evaluate the prospects of searching for TeV $\gamma$-ray sources with the WCDA, we present in this paper a projection for the one-year sensitivity of the WCDA to TeV $\gamma$-ray sources from TeVCat (footnote: this http URL) using an all-sky approach. Out of 128 TeVCat sources observable to the WCDA up to a zenith angle of $45^\circ$, we estimate that 42 would be detectable for one year of observations at a median energy of 1 TeV. Most of them are Galactic sources, and the extragalactic sources are Active Galactic Nuclei (AGN).

[25]  arXiv:2002.04837 [pdf, other]

Title: Data-driven MHD Simulation of the Formation and Initiation of a Large-scale Pre-flare Magnetic Flux Rope in Solar Active Region 12371

Authors: Wen He, Chaowei Jiang, Peng Zou, Aiying Duan, Xueshang Feng, Pingbing Zuo, Yi Wang

Comments: 10 pages, 6 figures, accept by ApJ

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

Solar eruptions are the most powerful drivers of space weather. To understand their cause and nature, it is crucial to know how the coronal magnetic field evolves before eruption. Here we study the formation process of a relatively large-scale magnetic flux rope (MFR) in active region NOAA~12371 that erupts with a major flare and coronal mass ejection on 2015 June 21. A data-driven numerical magnetohydrodynamic model is employed to simulate three-dimensional coronal magnetic field evolution of one-day duration before the eruption. Comparison between the observed features and our modeled magnetic field discloses how the pre-eruption MFR forms. Initially, the magnetic field lines were weakly twisted as being simple sheared arcades. Then a long MFR was formed along the polarity inversion line due to the complex photospheric motion, which is mainly shearing rather than twisting. The presence of the MFR is evidenced by a coherent set of magnetic field lines with twist number above unity. Below the MFR a current sheet is shown in the model, suggesting that tether-cutting reconnection plays a key role in the MFR formation. The MFR's flux grows as more and more field lines are twisted due to continuous injection of magnetic helicity by the photospheric motions. Meanwhile, the height of the MFR's axis increases monotonely from its formation. By an analysis of the decay index of its overlying field, we suggest that it is because the MFR runs into the torus instability regime and becomes unstable that finally triggers the eruption.

[26]  arXiv:2002.04853 [pdf, ps, other]

Title: Electromagnetic counterparts to gravitational wave events from Gaia

Authors: Z. Kostrzewa-Rutkowska, P. G. Jonker, S. T. Hodgkin, D. Eappachen, D. L. Harrison, S. E. Koposov, G. Rixon, L. Wyrzykowski, A. Yoldas, E. Breedt, A. Delgado, M. van Leeuwen, T. Wevers, P. W. Burgess, F. De Angeli, D. W. Evans, P. J. Osborne, M. Riello

Comments: MNRAS accepted

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

The recent discoveries of gravitational wave events and in one case also its electromagnetic (EM) counterpart allow us to study the Universe in a novel way. The increased sensitivity of the LIGO and Virgo detectors has opened the possibility for regular detections of EM transient events from mergers of stellar remnants. Gravitational wave sources are expected to have sky localisation up to a few hundred square degrees, thus Gaia as an all-sky multi-epoch photometric survey has the potential to be a good tool to search for the EM counterparts. In this paper we study the possibility of detecting EM counterparts to gravitational wave sources using the Gaia Science Alerts system. We develop an extension to current used algorithms to find transients and test its capabilities in discovering candidate transients on a sample of events from the observation periods O1 and O2 of LIGO and Virgo. For the gravitational wave events from the current run O3 we expect that about 16 (25) per cent should fall in sky regions observed by Gaia 7 (10) days after gravitational wave. The new algorithm will provide about 21 candidates per day from the whole sky.

[27]  arXiv:2002.04866 [pdf, other]

Title: $J$-factor estimation of Draco, Sculptor and Ursa Minor dwarf spheroidal galaxies with the member/foreground mixture model

Authors: Shun-ichi Horigome, Kohei Hayashi, Masahiro Ibe, Miho N. Ishigaki, Shigeki Matsumoto, Hajime Sugai

Comments: 13 pages, 13 figures, 3 tables. Submitted to MNRAS

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

Dwarf spheroidal galaxies (dSphs) are promising targets of indirect detection experiments searching for dark matter (DM) at present universe. Toward robust prediction for the amount of signal flux originating in DM annihilation inside dSphs, a precise determination of DM distributions as well as $J$-factors of the dSphs is particularly important. In this work, we estimate those of Draco, Sculptor, and Ursa Minor dSphs by an improved statistical method in which both foreground stars and dSph member stars are simultaneously taken into account. We define the likelihood function of the method as the so-called conditional one to remove sampling bias of observed stellar data. This improved method enables us to estimate DM distributions and $J$-factors of the dSphs directly from observed stellar data contaminated by foreground stars without imposing stringent membership criteria on the measured quantities.

[28]  arXiv:2002.04868 [pdf, other]

Title: Supernova feedback and the energy deposition in molecular clouds

Authors: William E. Lucas, Ian A. Bonnell, James E. Dale

Comments: 12 pages, 10 figures, MNRAS in press

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

Feedback from supernovae is often invoked as an important process in limiting star formation, removing gas from galaxies and hence as a determining process in galaxy formation. Here we report on numerical simulations investigating the interaction between supernova explosions and the natal molecular cloud. We also consider the cases with and without previous feedback from the high-mass star in the form of ionising radiation and stellar winds. The supernova is able to find weak points in the cloud and create channels through which it can escape, leaving much of the well shielded cloud largely unaffected. This effect is increased when the channels are pre-existing due to the effects of previous stellar feedback. The expanding supernova deposits its energy in the gas that is in these exposed channels, and hence sweeps up less mass when feedback has already occurred, resulting in faster outflows with less radiative losses. The full impact of the supernova explosion is then able to impact the larger scale of the galaxy in which it abides. We conclude that supernova explosions only have moderate effects on their dense natal environments but that with pre-existing feedback, the energetic effects of the supernova are able to escape and affect the wider scale medium of the galaxy.

[29]  arXiv:2002.04893 [pdf, other]

Title: Lensed or not lensed: Determining lensing magnifications for binary neutron star mergers from a single detection

Authors: Peter T. H. Pang, Otto A. Hannuksela, Tim Dietrich, Giulia Pagano, Ian W. Harry

Comments: 10 pages, 7 figures

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

Advanced LIGO and Advanced Virgo could observe the first lensed gravitational wave sources in the coming years, while the future Einstein Telescope could observe hundreds of lensed events. It is, therefore, crucial to develop methodologies to distinguish between lensed from unlensed gravitational-wave observations. A lensed signal not identified as such will lead to biases during the interpretation of the source. In particular, sources will appear to have intrinsically higher masses. No robust method currently exists to distinguish between the magnification bias caused by lensing and intrinsically high-mass sources. In this work, we show how to recognize lensed and unlensed binary neutron star systems through the measurement of their tidal effects for highly magnified sources as a proof-of-principle. The proposed method could be used to identify lensed binary neutron stars, which are the chief candidate for lensing cosmography studies. We apply our method on GW190425, finding no clear evidence for or against lensing, mainly due to the poor measurement of the event's tidal effects. However, we expect that future detections with better tidal measurements can yield better constraints.

[30]  arXiv:2002.04937 [pdf, ps, other]

Title: Possible detection of a new cyclotron feature in 4U 1700-37

Authors: Suman Bala, Jayashree Roy, Dipankar Bhattacharya

Comments: Accepted for publication in MNRAS journal

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

We present a spectral and timing study of the High Mass X-ray Binary transient source 4U 1700-37 using NuSTAR and ASTROSAT/LAXPC. The source is observed in two different flux states. A combined spectral analysis of NuSTAR's FPMA and FPMB shows the possible hint of a cyclotron line feature at $\sim$16 keV. The line feature is consistently present in different continuum models with at least 3$\sigma$ confidence level. We do not detect the presence of a previously reported ~39 keV cyclotron line in the combined spectra. A $\sim$16 keV cyclotron feature would suggest that the compact object is a neutron star with a magnetic field strength $\sim2.1\times$10$^{12}$ Gauss in the emission region. We also find the presence of a rare Ni $K{\alpha}$ emission line around 7.6 keV in the NuSTAR spectrum. We searched the NuSTAR and ASTROSAT data for coherent or quasi-periodic oscillation signals but found no evidence in the frequency range 0.1 mHz to 10$^3$ Hz.

[31]  arXiv:2002.04947 [pdf, other]

Title: Monitoring daytime and nighttime optical turbulence profiles with the PML instrument

Authors: Eric Aristidi, Aziz Ziad, Yan Fantéï-Caujolle, Julien Chabé, Christophe Giordano, Catherine Renaud, Henri Lantéri

Comments: AO4ELT6, Qu\'ebec, June 2019

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

The Profiler of Moon Limb is a recent instrument dedicated to the monitoring of optical turbulence profile of the atmosphere. Fluctuations of the Moon or the Sun limb allow to evaluate the index refraction structure constant C_n^2(h) and the wavefront coherence outer scale L_0(h) as a function of the altitude $h$. The atmosphere is split into 33 layers with an altitude resolution varying from 100m (at the ground) to 2km (in the upper atmosphere). Profiles are obtained every 3mn during daytime and nighttime. We report last advances on the instrument and present some results obtained at the Plateau de Calern (France).

[32]  arXiv:2002.04950 [pdf, other]

Title: Binary-binary scattering in the secular limit

Authors: Adrian S. Hamers, Johan Samsing

Comments: Submitted to MNRAS. 18 pages, 9 figures. Code can be found at this https URL

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

Binary-binary interactions are important in a number of astrophysical contexts including dense stellar systems such as globular clusters. Although less frequent than binary-single encounters, binary-binary interactions lead to a much richer range of possibilities such as the formation of stable triple systems. Here, we focus on the regime of distant binary-binary encounters, i.e., two binaries approaching each other on an unbound orbit with a periapsis distance Q much larger than the internal binary separations. This `secular' regime gives rise to changes in the orbital eccentricities and orientations, which we study using analytic considerations and numerical integrations. We show that `direct' interactions between the three orbits only occur starting at a high expansion order of the Hamiltonian (hexadecupole order), and that the backreaction of the outer orbit on the inner two orbits at lower expansion orders is weak. Therefore, to good approximation, one can obtain the changes of each orbit by using previously-known analytic results for binary-single interactions, and replacing the mass of the third body with the total mass of the companion binary. Nevertheless, we find some dependence of the `binarity' of the companion binary, and derive explicit analytic expressions for the secular changes that are consistent with numerical integrations. In particular, the eccentricity and inclination changes of orbit 1 due to orbit 2 scale as \eps_{SA1} (a_2/Q)^2 [m_3 m_4/(m_3+m_4)^2], where \eps_{SA1} is the approximate quadrupole-order change, and a_2 and (m_3,m_4) are the companion binary orbital semimajor axis and component masses, respectively. Our results are implemented in several Python scripts that are freely available.

[33]  arXiv:2002.04956 [pdf, other]

Title: Quantiles as Robust Probes of Non-Gaussianity in 21-cm Images

Authors: Alon Banet (1), Rennan Barkana (1), Anastasia Fialkov (2), Or Guttman (1) ((1) Tel Aviv University, (2) University of Cambridge)

Comments: 12 pages, 9 figures, submitted to MNRAS

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

The early epoch in which the first stars and galaxies formed is among the most exciting unexplored eras of the Universe. A major research effort focuses on probing this era with the 21-cm spectral line of hydrogen. While most research focused on statistics like the 21-cm power spectrum or the sky-averaged global signal, there are other ways to analyze tomographic 21-cm maps, which may lead to novel insights. We suggest statistics based on quantiles as a method to probe non-Gaussianities of the 21-cm signal. We show that they can be used in particular to probe the variance, skewness, and kurtosis of the temperature distribution, but are more flexible and robust than these standard statistics. We test these statistics on a range of possible astrophysical models, including different galactic halo masses, star-formation efficiencies, and spectra of the X-ray heating sources, plus an exotic model with an excess early radio background. Simulating data with angular resolution and thermal noise as expected for the Square Kilometre Array (SKA), we conclude that these statistics can be measured out to redshifts above 20 and offer a promising statistical method for probing early cosmic history.

[34]  arXiv:2002.04959 [pdf, other]

Title: The cosmic abundance of cold gas in the local Universe

Authors: Thomas J. Fletcher, Amelie Saintonge, Paula S. Soares, Andrew Pontzen

Comments: 8 pages, 6 figures, submitted to MNRAS

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

We determine the cosmic abundance of molecular hydrogen (H2) in the local universe from the xCOLD GASS survey. To constrain the H2 mass function at low masses and correct for the effect of the lower stellar mass limit of 10^9 Msun in the xCOLD GASS survey, we use an empirical approach based on an observed scaling relation between star formation rate and gas mass. We also constrain the HI and HI+H2 mass functions using the xGASS survey, and compare it to the HI mass function from the ALFALFA survey. We find the cosmic abundance of molecular gas in the local Universe to be Omega_H2=(5.34+/-0.47)x10^-5 h^-1. Molecular gas accounts for 19.6 +/- 3.9% of the total abundance of cold gas, Omega_HI+H2=(4.66+/-0.70)x10^-4 h^-1. Galaxies with stellar masses in excess of 10^9 Msun account for 89% of the molecular gas in the local Universe, while in comparison such galaxies only contain 73% of the cold atomic gas as traced by the HI 21cm line. The xCOLD GASS CO, molecular gas and cold gas mass functions and Omega_H2 measurements provide constraints for models of galaxy evolution and help to anchor blind ALMA and NOEMA surveys attempting to determine the abundance of molecular gas at high redshifts.

[35]  arXiv:2002.04965 [pdf, ps, other]

Title: Understanding the giant gamma-ray outburst on June 16, 2015 from the blazar 3C 279

Authors: K. K. Singh, P. J. Meintjes, F. A. Ramamonjisoa

Comments: 4 Figures, 2 Tables, Accepted for Publication in Astrophysics and Space Science (Ap&SS) Journal

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

A very bright and fast varying gamma-ray flare has been detected from the blazar 3C 279 on June 16, 2015. We have studied the broadband spectral energy distribution of the source during the flaring episode and in the low activity state using a simple one zone leptonic model. We find that an electron energy distribution described by a broken power law can be used to reproduce the broadband emissions during the high and low activity states. The flux measurements at radio, infrared and optical frequencies are reproduced by the synchrotron emission resulting from the relativistic electrons in a jet magnetic field strength of 0.37 G. The gamma-ray emission from the blazar 3C 279 is attributed to the Comptonization of the IR seed photons from the dusty torus with a temperature of 870 K. The outburst from the source observed on June 16, 2015 can be ascribed to an efficient acceleration process associated with a sudden enhancement in the electron energy density in the emitting region with respect to the low activity state. The fast gamma-ray variability at a minute timescale implies that the emission during the flare originates from a more compact region and the size of the emission zone in the low activity state is found to be four times larger than that during the flare. We have also used the model parameters derived from the broadband spectral energy distribution modelling to investigate a few physical properties of the jet during the outburst.

[36]  arXiv:2002.04966 [pdf, other]

Title: A Markov Chain Monte Carlo approach for measurement of jet precession in radio-loud active galactic nuclei

Authors: Maya A. Horton, Martin J. Hardcastle, Shaun C. Read, Martin G. H. Krause

Comments: 9 pages, 8 figures, accepted for Monthly Notices

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

Jet precession can reveal the presence of binary systems of supermassive black holes. The ability to accurately measure the parameters of jet precession from radio-loud AGN is important for constraining the binary supermassive black hole population, which are expected as a result of hierarchical galaxy evolution. The age, morphology, and orientation along the line of sight of a given source often result in uncertainties regarding jet path. This paper presents a new approach for efficient determination of precession parameters using a 2D MCMC curve-fitting algorithm which provides us a full posterior probability distribution on the fitted parameters. Applying the method to Cygnus A, we find evidence for previous suggestions that the source is precessing. Interpreted in the context of binary black holes leads to a constraint of parsec scale and likely sub-parsec orbital separation for the putative supermassive binary.

[37]  arXiv:2002.04978 [pdf]

Title: Experimental Study of Ethylene Evaporites under Titan Conditions

Authors: E. C. Czaplinski, Woodrow A. Gilbertson, Kendra K. Farnsworth, Vincent F. Chevrier

Comments: 33 pages, 12 figures, 2 tables, published in ACS Earth and Space Chemistry

Journal-ref: ACS Earth and Space Chemistry 3 (2019) 2353-2362

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

Titan has an abundance of lakes and seas, as confirmed by Cassini. Major components of these liquid bodies include methane ($CH_4$) and ethane ($C_2H_6$); however, evidence indicates that minor components such as ethylene ($C_2H_4$) may also exist in the lakes. As the lake levels drop, 5 $\mu m$-bright deposits, resembling evaporite deposits on earth, are left behind. Here, we provide saturation values, evaporation rates, and constraints on ethylene evaporite formation by using a Titan simulation chamber capable of reproducing Titan surface conditions (89-94 K, 1.5 bar $N_2$). Experimental samples were analyzed using Fourier transform infrared spectroscopy, mass, and temperature readings. Ethylene evaporites form more quickly in a methane solvent than in an ethane solvent or in a mixture of methane/ethane. We measured an average evaporation rate of $(2.8 \pm 0.3) \times 10^{-4} kg \; m^{-2} \; s^{-1}$ for methane and an average upper limit evaporation rate of less than $5.5 \times 10^{-6} kg \; m^{-2} \; s^{-1}$ for ethane. Additionally, we observed red shifts in ethylene absorption bands at 1.630 and 2.121 $\mu m$ and the persistence of a methane band at 1.666 $\mu m$.

[38]  arXiv:2002.04984 [pdf, ps, other]

Title: Chemical modelling of FU Ori protoplanetary disks

Authors: Tamara Molyarova, Vitaly Akimkin, Dmitry Semenov, Péter Ábrahám, Thomas Henning, Ágnes Kóspál, Eduard Vorobyov, Dmitri Wiebe

Comments: 2 pages, 2 figures

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

Luminosity outbursts of the FUOri type stars, which have a magnitude of $\sim100 L_{\odot}$ and last for decades, may affect chemical composition of the surrounding protoplanetary disk. Using astrochemical modeling we analyze the changes induced by the outburst and search for species sensitive to the luminosity rise. Some changes in the disk molecular composition appear not only during the outburst itself but can also retain for decades after the end of the outburst. We analyze main chemical processes responsible for these effects and assess timescales at which chemically inert species return to the pre-outburst abundances.

[39]  arXiv:2002.05006 [pdf, other]

Title: Order-disorder phase transition in black-hole star clusters -- III. A mono-energetic cluster

Authors: Scott Tremaine

Comments: MNRAS, in press

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

Supermassive black holes at the centres of galaxies are often surrounded by dense star clusters. For a wide range of cluster properties and orbital radii the resonant relaxation times in these clusters are much shorter than the Hubble time. Since resonant relaxation conserves semimajor axes, these clusters should be in the maximum-entropy state consistent with the given semimajor axis distribution. We determine these maximum-entropy equilibria in a simplified model in which all of the stars have the same semimajor axes. We find that the cluster exhibits a phase transition from a disordered, spherical, high-temperature equilibrium to an ordered low-temperature equilibrium in which the stellar orbits have a preferred orientation or line of apsides. Here `temperature' is a measure of the non-Keplerian or self-gravitational energy of the cluster; in the spherical state, temperature is a function of the rms eccentricity of the stars. We explore a simple two-parameter model of black-hole star clusters -- the two parameters are semimajor axis and black-hole mass --- and find that clusters are susceptible to the lopsided phase transition over a range of ~100 in semimajor axis, mostly for black-hole masses less than $10^{7.5}$ solar masses.

[40]  arXiv:2002.05007 [pdf, ps, other]

Title: The Relationship between Chirality, Sense of Rotation, and Hemispheric Preference of Solar Eruptive Filaments

Authors: Zhenjun Zhou, Rui Liu, Xing Cheng, Chaowei Jiang, Yuming Wang, Lijuan Liu, Jun Cui

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

The orientation, chirality, and dynamics of solar eruptive filaments is a key to understanding the magnetic field of coronal mass ejections (CMEs) and therefore to predicting the geoeffectiveness of CMEs arriving at Earth. However, confusion and contention remain over the relationship between the filament chirality, magnetic helicity, and sense of rotation during eruption. To resolve the ambiguity in observations, in this paper, we used stereoscopic observations to determine the rotation direction of filament apex and the method proposed by Chen et al. (2014) to determine the filament chirality. Our sample of 12 eruptive active-region filaments establishes a strong one-to-one relationship, i.e., during the eruption, sinistral/dextral filaments (located in the southern/northern hemisphere) rotate clockwise/counterclockwise when viewed from above, and corroborates a weak hemispheric preference, i.e., a filament and related sigmoid both exhibit a forward (reverse) S shape in the southern (northern) hemisphere, which suggests that the sigmoidal filament is associated with a low-lying magnetic flux rope with its axis dipped in the middle. As a result of rotation, the projected S shape of a filament is anticipated to be reversed during eruption.

[41]  arXiv:2002.05044 [pdf, ps, other]

Title: Internal motions in OB-associations with Gaia DR2

Authors: A. M. Melnik, A. K. Dambis

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

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

We study the motions inside 28 OB-associations with the use of Gaia DR2 proper motions. The average velocity dispersion calculated for 28 OB-associations including more than 20 stars with Gaia DR2 proper motion is sigma_v =4.5 km s-1. The median virial and stellar masses of OB-associations are M_vir=8.9 x 10^5 and M_st=8.1 x 10^3 Ms, respectively. The median star-formation efficiency in parent giant molecular clouds appears to be epsilon=1.2 per cent. Gaia DR2 proper motions confirm the expansion in the Per OB1, Car OB1 and Sgr OB1 associations found earlier with Gaia DR1 data. We also detect the expansion in Gem OB1, Ori OB1 and Sco OB1 associations which became possible for the first time now when analyzed with Gaia DR2 proper motions. The analysis of the distribution of OB-stars in the Per OB1 association shows the presence of a shell-like structure with the radius of 40 pc. Probably, the expansion of the Per OB1 association started with the velocity greater than the present-day expansion velocity equal to 5.0 +\- 1.7 km s-1.

[42]  arXiv:2002.05052 [pdf, other]

Title: Probing the absorption of gamma-rays by IR radiation from the dusty torus in FSRQs with the Cherenkov Telescope Array

Authors: Giorgio Galanti, Marco Landoni, Fabrizio Tavecchio, Stefano Covino

Comments: 13 pages, 13 figures

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

Within the classical emission model, where the emission region is placed within the broad line region (BLR), flat spectrum radio quasars (FSRQs) were believed not to emit photons with energies above few tens of GeV because of the absorption with the optical-UV photons from the BLR. However, photons with observed energies up to about $300 \, \rm GeV$ have been detected for few FSRQs, whose most iconic example is PKS 1441+25 at redshift $z = 0.94$. The most conservative explanation for these observations is that the emission occurs at distances comparable to the size of the dusty torus. In this case, absorption of high-energy gamma-ray photons for energies above $200-300 \, {\rm GeV}$ is dominated by the interaction with infrared radiation emitted by the torus. We investigate if current observational data about FSRQs in flaring state can give us information about: (i) the importance of the torus absorption and (ii) the properties of the torus i.e. its temperature and its geometry. We find that present data do not arrive at energies where the torus influence is prominent and as a result it is currently hardly possible to infer torus properties from observations. However, with dedicated simulations, we demonstrate that observations with the forthcoming Cherenkov Telescope Array (CTA) will be able to constrain the torus parameters (temperature and geometry).

[43]  arXiv:2002.05072 [pdf, other]

Title: Packed Ultra-wideband Mapping Array (PUMA): Astro2020 RFI Response

Authors: Emanuele Castorina, Simon Foreman, Dionysios Karagiannis, Adrian Liu, Kiyoshi W. Masui, Pieter D. Meerburg, Laura B. Newburgh, Paul O'Connor, Andrej Obuljen, Hamsa Padmanabhan, J. Richard Shaw, Anže Slosar, Paul Stankus, Peter T. Timbie, Benjamin Wallisch, Martin White

Comments: 46 pages, 16 figures, 7 tables; response to the request for information (RFI) by the Panel on Radio, Millimeter, and Submillimeter Observations from the Ground (RMS) of the Astro2020 Decadal Survey regarding PUMA APC submission (arXiv:1907.12559)

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

The Packed Ultra-wideband Mapping Array (PUMA) is a proposed low-resolution transit interferometric radio telescope operating over the frequency range 200 - 1100MHz. Its rich science portfolio will include measuring structure in the universe from redshift z = 0.3 to 6 using 21cm intensity mapping, detecting one million fast radio bursts, and monitoring thousands of pulsars. It will allow PUMA to advance science in three different areas of physics (the physics of dark energy, the physics of cosmic inflation and time-domain astrophysics). This document is a response to a request for information (RFI) by the Panel on Radio, Millimeter, and Submillimeter Observations from the Ground (RMS) of the Decadal Survey on Astronomy and Astrophysics 2020. We present the science case of PUMA, the development path and major risks to the project.

[44]  arXiv:2002.05073 [pdf, other]

Title: Jet-shaped geometrically modified light curves of core collapse supernovae

Authors: Noa Kaplan, Noam Soker (Technion, Israel)

Comments: Will be submitted in 2 days to allow comments by readers

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

We build three simple bipolar ejecta models for core collapse supernovae (CCSN), as expected when the explosion is driven by strong jets, and show that for an observer located in the equatorial plane of the ejecta, the light curve has a rapid luminosity decline, and even an abrupt drop. In calculating the geometrically modified photosphere we assume that the ejecta has an axisymmetrical structure composed of an equatorial ejecta and faster polar ejecta, and has a uniform effective temperature. At early times the photosphere in the polar ejecta grows faster than the equatorial one, leading to higher luminosity relative to a spherical explosion. The origin of the extra radiated energy is the jets. At later times the optical depth decreases faster in the polar ejecta, and the polar photosphere becomes hidden behind the equatorial ejecta for an observer in the equatorial plane, leading to a rapid luminosity decline. For a model where the jets inflate two low-density polar bubbles, the luminosity decline might be abrupt. This model enables us to fit the abrupt decline in the light curve of SN2018don.

[45]  arXiv:2002.05077 [pdf, other]

Title: Predictions for the hydrogen-free ejecta of pulsational pair-instability supernovae

Authors: M. Renzo, R. Farmer, S. Justham, Y. Götberg, S. E. de Mink, E. Zapartas, P. Marchant, N. Smith

Comments: 17 pages + 3 appendixes, submitted to A&A, simulation input and output will be available at acceptance

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

Present time-domain astronomy efforts will unveil a variety of rare transients. We focus here on pulsational pair-instability evolution, which can result in signatures observable with electromagnetic and gravitational waves. We simulate grids of bare helium stars to characterize the resulting black hole (BH) masses and ejecta composition, velocity, and thermal state. The stars do not react "elastically" to the thermonuclear explosion: there is not a one-to-one correspondence between pair-instability driven ignition and mass ejections, causing ambiguity in what is an observable pulse. In agreement with previous studies, we find that for carbon-oxygen core masses 28Msun< M_CO<30.5Msun the explosions are not strong enough to affect the surface. With increasing mass, they first cause large radial expansion (30.5Msun<M_CO<31.4Msun), and finally, also mass ejection episodes (M_CO>31.4Msun). The lowest mass to be fully disrupted in a pair-instability supernova is M_CO=57Msun. Models with M_CO>121Msun reach the photodisintegration regime, resulting in BHs with M_BH>125Msun. If the pulsating models produce BHs via (weak) explosions, the previously-ejected material might be hit by the blast wave. We characterize the H-free circumstellar material from the pulsational pair-instability of helium cores assuming simply that the ejecta maintain a constant velocity after ejection. Our models produce He-rich ejecta with mass 10^{-3}Msun<M_CSM<40Msun. These ejecta are typically launched at a few thousand \kms and reach distances of ~10^{12}-10^{15} cm before core-collapse. The delays between mass ejection events and the final collapse span a wide and mass-dependent range (from sub-hour to 10^4 years), and the shells ejected can also collide with each other. The range of properties we find suggests a possible connection with (some) type Ibn supernovae.

[46]  arXiv:2002.05116 [pdf, other]

Title: Aliphatic hydrocarbon content of the interstellar dust

Authors: B. Günay, T. W. Schmidt, M. G. Burton, M. Afşar, O. Krechkivska, K. Nauta, S. H. Kable, A. Rawal

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

In the interstellar medium, carbon is distributed between the gas and solid phases. However, while about half of the expected carbon abundance can be accounted for in the gas phase, there is considerable uncertainty as to the amount incorporated in interstellar dust.
The aliphatic component of the carbonaceous dust is of particular interest because it produces a significant 3.4 $\mu$m absorption feature when viewed against a background radiation source. The optical depth of the 3.4 $\mu$m absorption feature is related to the number of aliphatic carbon C-H bonds along the line of sight. It is possible to estimate the column density of carbon locked up in the aliphatic hydrocarbon component of interstellar dust from quantitative analysis of the 3.4 $\mu$m interstellar absorption feature providing that the absorption coefficient of aliphatic hydrocarbons incorporated in the interstellar dust is known.
We generated laboratory analogues of interstellar dust by experimentally mimicking interstellar/circumstellar conditions. The resultant spectra of these dust analogues closely match those from astronomical observations. The measurements of the absorption coefficient of aliphatic hydrocarbons incorporated in the analogues were carried out by a procedure which combined FTIR and $^{13}$C NMR spectroscopies. The absorption coefficients obtained for both interstellar analogues were found to be in close agreement (4.76(8) $\times$ 10$^{-18}$ cm group$^{-1}$ and 4.69(14) $\times$ 10$^{-18}$ cm group$^{-1}$), less than half those obtained in studies using small aliphatic molecules. The results thus obtained permit direct calibration of the astronomical observations, providing rigorous estimates of the amount of aliphatic carbon in the interstellar medium.

[47]  arXiv:2002.05154 [pdf, other]

Title: Probing the Seesaw Mechanism with Cosmological data

Authors: J. G. Rodrigues, Micol Benetti, Marcela Campista, Jailson Alcaniz

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

We investigate cosmological consequences of an inflationary model which incorporates a generic seesaw extension (types I and II) of the Standard Model of Particle Physics. A non-minimal coupling between the inflaton field and the Ricci scalar is considered as well as radiative corrections at one loop order. This connection between the inflationary dynamics with neutrino physics results in a predictive model whose observational viability is investigated in light of the current cosmic microwave background data, baryon acoustic oscillation observations and type Ia supernovae measurements. Our results show that the non-minimal coupled seesaw potential provides a good description of the observational data when radiative corrections are positive. Such result favours the type II seesaw mechanism over type I and may be an indication for physics beyond the Standard Model.

[48]  arXiv:2002.05157 [pdf, other]

Title: IGAPS: the merged IPHAS and UVEX optical surveys of theNorthern Galactic Plane

Authors: M. Monguió, R. Greimel, J. E. Drew, G. Barentsen, P. J. Groot, M. J. Irwin, J. Casares, B. T.Gänsicke, P. J. Carter, J. M. Corral-Santana, N. P. Gentile-Fusillo, S. Greiss, L. M. van Haaften, M. Hollands, D. Jones, T. Kupfer, C. J. Manser, D. N. A. Murphy, A. F. McLeod, T. Oosting, Q. A. Parker, S. Pyrzas, P. Rodríguez-Gil, J. van Roestel, S. Scaringi, P. Schellart, O. Toloza, O. Vaduvescu, L. van Spaandonk, K. Verbeek, N. J. Wright, J. Eislöffel, J. Fabregat, A. Harris, R. A. H. Morris, S. Phillipps, R. Raddi, L. Sabin, Y. Unruh, J. S Vink, R. Wesson, A. Cardwell, R. K.Cochrane, S. Doostmohammadi, T. Mocnik, H. Stoev, L. Suárez-Andrés, V. Tudor, T. G. Wilson, T. J. Zegmott

Comments: 28 pages, 22 figures

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

The INT Galactic Plane Survey (IGAPS) is the merger of the optical photometric surveys, IPHAS and UVEX, based on data from the Isaac Newton Telescope (INT) obtained between 2003 and 2018. Here, we present the IGAPS point source catalogue. It contains 295.4 million rows providing photometry in the filters, i, r, narrow-band Halpha, g and U_RGO. The IGAPS footprint fills the Galactic coordinate range, |b| < 5deg and 30deg < l < 215deg. A uniform calibration, referred to the Pan-STARRS system, is applied to g, r and i, while the Halpha calibration is linked to r and then is reconciled via field overlaps. The astrometry in all 5 bands has been recalculated on the Gaia DR2 frame. Down to i ~ 20 mag (Vega system), most stars are also detected in g, r and Halpha. As exposures in the r band were obtained within the IPHAS and UVEX surveys a few years apart, typically, the catalogue includes two distinct r measures, r_I and r_U. The r 10sigma limiting magnitude is ~21, with median seeing 1.1 arcsec. Between ~13th and ~19th magnitudes in all bands, the photometry is internally reproducible to within 0.02 magnitudes. Stars brighter than r=19.5 have been tested for narrow-band Halpha excess signalling line emission, and for variation exceeding |r_I-r_U| = 0.2 mag. We find and flag 8292 candidate emission line stars and over 53000 variables (both at >5sigma confidence). The 174-column catalogue will be available via CDS Strasbourg.

Cross-lists for Thu, 13 Feb 20

[49]  arXiv:2002.04615 (cross-list from hep-ph) [pdf, other]

Title: New Sensitivity Curves for Gravitational-Wave Experiments

Authors: Kai Schmitz

Comments: 28+14+11 pages main text / appendix / references, 11 figures, 4 tables. Companion paper: 1909.11356

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

Gravitational waves (GWs) from strong first-order phase transitions (SFOPTs) in the early Universe are a prime target for upcoming GW experiments. In this paper, I construct novel peak-integrated sensitivity curves (PISCs) for these experiments, which faithfully represent their projected sensitivities to the GW signal from a cosmological SFOPT by explicitly taking into account the expected shape of the signal. Designed to be a handy tool for phenomenologists and model builders, PISCs allow for a quick and systematic comparison of theoretical predictions with experimental sensitivities, as I illustrate by a large range of examples. PISCs also offer several advantages over the conventional power-law-integrated sensitivity curves (PLISCs); in particular, they directly encode information on the expected signal-to-noise ratio for the GW signal from a SFOPT. I provide semianalytical fit functions for the exact numerical PISCs of LISA, DECIGO, and BBO. In an appendix, I moreover present a detailed review of the noise power spectra of a large number of GW experiments. In a companion paper [1909.11356], the concept of PISCs is used to perform an in-depth study of the GW signal from the SFOPT in the real-scalar-singlet extension of the standard model.

[50]  arXiv:2002.04856 (cross-list from gr-qc) [pdf, other]

Title: Vacuum decay in the presence of a cosmic string

Authors: Hassan Firouzjahi, Asieh Karami, Tahereh Rostami

Comments: 21 pages, 5 figures

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

We study the false vacuum decay and bubble nucleation in the presence of a cosmic string in dS spacetime. A cosmic string induces a deficit angle in spacetime around itself so the nucleated bubble has the shape of a rugby ball. Working in thin wall approximation and using the junction conditions we study the dynamics of the bubble wall and calculate the Euclidean action. An interesting feature in our analysis is that the tension of the string is screened by the bubble such that an observer inside the bubble measures a different value of the tension than an outside observer. We show that the string can act as a catalyzer in which the nucleation rate is enhanced compared to the Coleman-de Luccia instanton. However, in general, the nucleation rate is not a monotonic function of the difference between the two tensions so in some regions of the parameters space the nucleation rate may be smaller than the Coleman-de Luccia bubble.

[51]  arXiv:2002.04864 (cross-list from physics.ins-det) [pdf, other]

Title: High-Dynamic-Range Mode-Decomposition for Interferometric Gravitational Wave Detectors and Associated Alignment Considerations

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

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

Accurate readout of low-power optical higher-order spatial modes is of increasing importance to the precision metrology community. Such devices may prevent mode mismatches from degrading quantum and thermal noise mitigation strategies. Direct mode analysis sensors are a promising technology for real time monitoring of arbitrary higher-order modes. We demonstrate this technology with photo-diode readout to mitigate the typically low dynamic range of CCDs. We experimentally demonstrate the effect of a relative misalignment between the phase-plate and the photo-diode on the readout of higher-order modes, then derive this response. We then compute the residual the effects of the finite photo-diode aperture on the dynamic range and discuss implementation considerations for future sensors.

[52]  arXiv:2002.04875 (cross-list from gr-qc) [pdf, ps, other]

Title: Black holes and naked singularities from Anton-Schmidt's fluids

Authors: Salvatore Capozziello, Rocco D'Agostino, Daniele Gregoris

Comments: 6 pages, no figures

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

Adopting the Tolman-Oppenheimer-Volkoff formalism, we propose a new analytical solution for a static and spherically symmetric black hole where the cosmological constant is generalized to a non-isotropic Anton-Schmidt fluid acting as a unified dark energy - dark matter source. Our novel result can describe a black hole in energetic equilibrium with the surrounding universe. We thus investigate the interplay between the mass of the black hole and the parameters of the Anton-Schmidt equation of state, and physically interpret the solution as a family of space-time metrics that may describe both Schwarzschild-de Sitter black holes and naked singularities. The result opens a new window for further constraining the physical properties of the cosmic fluid using the Event Horizon Telescope results, which complement the analysis relying on classical cosmological observations.

[53]  arXiv:2002.04925 (cross-list from hep-th) [pdf, other]

Title: Strengthening the de Sitter swampland conjecture in warm inflation

Authors: Robert Brandenberger, Vahid Kamali, Rudnei O. Ramos

Comments: 7 pages

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)

The "de Sitter constraint" on the space of effective scalar field theories consistent with superstring theory provides a lower bound on the slope of the potential of a scalar field which dominates the evolution of the Universe, e.g., a hypothetical inflaton field. Whereas models of single scalar field inflation with a canonically normalized field do not obey this constraint, it has been claimed recently in the literature that models of warm inflation can be made compatible with it in the case of large dissipation. The de Sitter constraint is known to be derived from entropy considerations. Since warm inflation necessary involves entropy production, it becomes necessary to determine how this entropy production will affect the constraints imposed by the swampland conditions. Here, we generalize these entropy considerations to the case of warm inflation and show that the condition on the slope of the potential remains essentially unchanged and is, hence, robust even in the warm inflation dynamics. We are then able to conclude that models of warm inflation indeed can be made consistent with the "swampland" criteria.

[54]  arXiv:2002.04983 (cross-list from physics.ins-det) [pdf, other]

Title: In-Flight Performance of the Advanced Radiation Detector for UAV Operations (ARDUO)

Authors: Carolyn M. Chen, Laurel E. Sinclair, Richard Fortin, Maurice Coyle, Claire Samson

Comments: 24 pages, 8 figures, presented at SORMA XVII 2018 and published in NIMA

Journal-ref: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol: 954, Article 161609, 2020

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

Natural Resources Canada (NRCan) is responsible for the provision of aerial radiometric surveys in the event of a radiological or nuclear emergency in Canada. Manned aerial surveys are an essential element of the planned consequence management operation, as demonstrated by the recovery work following the 2011 Tohoku earthquake and tsunami, and their effects in Fukushima, Japan. Flying lower and slower than manned aircraft, an unmanned aerial vehicle (UAV) can provide improved spatial resolution. In particular, hot spot activity can be underestimated in manned survey results as the higher flight altitude and wider line spacing effectively average the hot spot over a larger area. Moreover, a UAV can enter an area which is hazardous for humans. NRCan has been investigating the inclusion of UAV-borne radiation survey spectrometers into its aerial survey response procedures. The Advanced Radiation Detector for UAV Operations (ARDUO) was developed to exploit the flight and lift capabilities available in the under 25kg class of UAVs. The detector features eight 2.8cm x 2.8cm x 5.6cm CsI(Tl) crystals in a self-shielding configuration, read out with silicon photomultipliers and digitized using miniaturized custom electronics. The ARDUO is flown on a main- and tail-rotor UAV called Responder which has a 6kg lift capacity and up to 40min. endurance. The performance of the ARDUO-Responder UAV system was characterized in both lab and outdoor trials. Outdoor trials consisted of aerial surveys over sealed point sources and over a distributed source. Results show how the directional response of the ARDUO can provide an indication in real time of source location for in-flight guidance. As well, the results show how use of the directional information in post-acquisition processing can result in improved spatial resolution of radiation features for both point and distributed sources.

Replacements for Thu, 13 Feb 20

[55]  arXiv:1710.11072 (replaced) [pdf, other]

Title: Thermodynamic potential for quark-gluon plasma with finite quark masses and chemical potential

Authors: Mayukh R. Gangopadhyay, Grant J. Mathews, J. Pocahontas Olson

Comments: 16 pages, 6 figures, Matches published version

Journal-ref: J. Phys. Commun. 4 (2020) 025004

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

[56]  arXiv:1812.06986 (replaced) [pdf, other]

Title: A Global Analysis of Dark Matter Signals from 27 Dwarf Spheroidal Galaxies using 11 Years of Fermi-LAT Observations

Authors: Sebastian Hoof, Alex Geringer-Sameth, Roberto Trotta

Comments: 27+5 pages, 10 figures. Version 2 corresponds to the Accepted Manuscript version of the JCAP article; the analysis has been updated to Pass 8 R3 data plus 4FGL catalogue, with one more year of data and more annihilation channels. Supplementary Material (tabulated limits, likelihoods, and posteriors) is available on Zenodo at this https URL

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

[57]  arXiv:1905.03738 (replaced) [pdf, other]

Title: Search for Ultra-High-Energy Neutrinos with the Telescope Array Surface Detector

Authors: R.U. Abbasi, M. Abe, T. Abu-Zayyad, M. Allen, R. Azuma, E. Barcikowski, J.W. Belz, D.R. Bergman, S.A. Blake, R. Cady, B.G. Cheon, J. Chiba, M. Chikawa, A. di Matteo, T. Fujii, K. Fujita, R. Fujiwara, M. Fukushima, G. Furlich, W. Hanlon, M. Hayashi, Y. Hayashi, N. Hayashida, K. Hibino, K. Honda, D. Ikeda, N. Inoue, T. Ishii, R. Ishimori, H. Ito, D. Ivanov, H.M. Jeong, S. Jeong, C.C.H. Jui, K. Kadota, F. Kakimoto, O. Kalashev, K. Kasahara, H. Kawai, S. Kawakami, S. Kawana, K. Kawata, E. Kido, H.B. Kim, J.H. Kim, J.H. Kim, S. Kishigami, S. Kitamura, Y. Kitamura, V. Kuzmin, M. Kuznetsov, Y.J. Kwon, K.H. Lee, B. Lubsandorzhiev, J.P. Lundquist, K. Machida, K. Martens, T. Matsuyama, J.N. Matthews, R. Mayta, M. Minamino, K. Mukai, I. Myers, K. Nagasawa, S. Nagataki, K. Nakai, R. Nakamura, T. Nakamura, et al. (74 additional authors not shown)

Comments: 10 pages, 4 figures, accepted to JETP

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

[58]  arXiv:1905.13233 (replaced) [pdf, other]

Title: Horizon-AGN virtual observatory -- 2: Template-free estimates of galaxy properties from colours

Authors: Iary Davidzon, Clotilde Laigle, Peter L. Capak, Olivier Ilbert, Daniel C. Masters, Shoubaneh Hemmati, Nikolaos Apostolakos, Jean Coupon, Sylvain de la Torre, Julien Devriendt, Yohan Dubois, Daichi Kashino, Stephane Paltani, Christophe Pichon

Comments: Published on MNRAS in November 2019. Horizon-AGN photometric catalogues are available at this https URL

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

[59]  arXiv:1907.07601 (replaced) [pdf, ps, other]

Title: Entanglement entropy of Primordial Black Holes after inflation

Authors: Llorenç Espinosa-Portalés, Juan García-Bellido

Comments: 13 pages. Typos corrected; references, extra section and comments added. Matches version published in PRD

Journal-ref: Phys. Rev. D 101, 043514 (2020)

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

[60]  arXiv:1907.11638 (replaced) [pdf, other]

Title: Beyond the Runge-Kutta-Wentzel-Kramers-Brillouin method

Authors: Jamie Bamber, Will Handley

Comments: 13 pages, 9 figures, accepted by PRD. This version includes stylistic corrections from PRD

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

[61]  arXiv:1908.04830 (replaced) [pdf, ps, other]

Title: Gravity theory with an extra dimension of zero length

Authors: Sandipan Sengupta

Comments: 19 pages, Expanded version

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

[62]  arXiv:1909.00029 (replaced) [pdf, other]

Title: Physical modelling of galaxy clusters and Bayesian inference in astrophysics

Authors: Kamran Javid

Comments: PhD thesis, Univ Cambridge, May 2018

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

[63]  arXiv:1909.01478 (replaced) [pdf, other]

Title: Trans-Neptunian objects found in the first four years of the Dark Energy Survey

Authors: Pedro H. Bernardinelli, Gary M. Bernstein, Masao Sako, Tongtian Liu, William R. Saunders, Tali Khain, Hsing Wen Lin, David W. Gerdes, Dillon Brout, Fred C. Adams, Matthew Belyakov, Aditya Inada Somasundaram, Lakshay Sharma, Jennifer Locke, Kyle Franson, Juliette C. Becker, Kevin Napier, Larissa Markwardt, James Annis, T. M. C. Abbott, S. Avila, D. Brooks, D. L. Burke, A. Carnero Rosell, M. Carrasco Kind, F. J. Castander, L. N. da Costa, J. De Vicente, S. Desai, H. T. Diehl, P. Doel, S. Everett, B. Flaugher, J. García-Bellido, D. Gruen, R. A. Gruendl, J. Gschwend, G. Gutierrez, D. L. Hollowood, D. J. James, M. W. G. Johnson, M. D. Johnson, E. Krause, N. Kuropatkin, M. A. G. Maia, M. March, R. Miquel, F. Paz-Chinchón, A. A. Plazas, A. K. Romer, E. S. Rykoff, C. Sánchez, E. Sanchez, et al. (11 additional authors not shown)

Comments: 33 pages, accepted to ApJS, table of objects found in the ancillary files

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

[64]  arXiv:1909.01828 (replaced) [pdf, other]

Title: hi_class: Background Evolution, Initial Conditions and Approximation Schemes

Authors: Emilio Bellini, Ignacy Sawicki, Miguel Zumalacárregui

Comments: 35 pages + appendices, 11 figures. Updated discussions. Code available on this https URL

Journal-ref: JCAP02(2020)008

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)

[65]  arXiv:1909.01934 (replaced) [pdf, other]

Title: Constraining the Gravitational-Wave Afterglow From a Binary Neutron Star Coalescence

Authors: Sharan Banagiri, Michael W. Coughlin, James Clark, Paul D. Lasky, M. A. Bizouard, Colm Talbot, Eric Thrane, Vuk Mandic

Comments: 6 pages, 4 figured

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

[66]  arXiv:1909.03053 (replaced) [pdf, ps, other]

Title: Improved Bethe-Heitler formula

Authors: Wei Zhu

Comments: 35 pages, 8 figures. A reviwed version and the title is changed. Accepted for publication on NPB

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

[67]  arXiv:1910.04315 (replaced) [pdf, other]

Title: Footprints of Doppler and Aberration Effects in CMB Experiments: Statistical and Cosmological Implications

Authors: Siavash Yasini, Elena Pierpaoli

Comments: 17 pages, 16 figures, 3 appendices, 1 python package: this https URL

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

[68]  arXiv:1912.02201 (replaced) [pdf, other]

Title: The impact of star formation sampling effects on the spectra of lensed $z>6$ galaxies detectable with $\textit{JWST}$

Authors: Anton Vikaeus, Erik Zackrisson, Christian Binggeli

Comments: 8 pages, 5 figures. Accepted by MNRAS 10 December 2019

Journal-ref: Monthly Notices of the Royal Astronomical Society, Volume 492, Issue 2, February 2020, Pages 1706 to 1712

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

[69]  arXiv:1912.04156 (replaced) [pdf, ps, other]

Title: Multifrequency Study on the Mode Switching of PSR J0614+2229

Authors: Yanrong Zhang, Hongguang Wang, Xiujian Huang, Jianling Chen

Comments: 13 pages, 7 figures, 3 tables

Journal-ref: 2020, ApJ, 890, 31

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

[70]  arXiv:1912.09858 (replaced) [pdf, other]

Title: Understanding the suppression of structure formation from dark matter$\unicode{x2013}$dark energy momentum coupling

Authors: Finlay Noble Chamings, Anastasios Avgoustidis, Edmund J. Copeland, Anne M. Green, Alkistis Pourtsidou

Comments: 10 pages, 10 figures, v2: version to appear in Phys. Rev. D with minor changes to discussion

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

[71]  arXiv:1912.10716 (replaced) [pdf, other]

Title: Molecular gas in distant brightest cluster galaxies

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

Comments: 18 pages, 4 figures, accepted for publication in A&A

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

[72]  arXiv:2001.00421 (replaced) [pdf, other]

Title: Interpretation of ALMA velocity map for the obscuring torus in NGC1068

Authors: E.Yu. Bannikova, N.A. Akerman, A.V. Sergeyev

Comments: 10 pages, 3 figures

Journal-ref: Astronomical and Astrophysical Transactions, vol.31, issue 4, 2020

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

[73]  arXiv:2001.07730 (replaced) [pdf, other]

Title: The Clustering of X-ray Luminous Quasars

Authors: M. C. Powell, C. M. Urry, N. Cappelluti, J. T. Johnson, S. M. LaMassa, T. T. Ananna, K. E. Kollmann

Comments: Accepted for publication in ApJ

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

[74]  arXiv:2001.09562 (replaced) [pdf, ps, other]

Title: The effect of CO-H2O collisions in the rotational excitation of cometary CO

Authors: A. Faure, F. Lique, J. Loreau

Comments: 8 pages, 7 figures, accepted for publication in MNRAS (January 20 2020)

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Chemical Physics (physics.chem-ph)

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• Replacements