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New submissions for Mon, 3 Feb 20

[1]  arXiv:2001.11508 [pdf, other]

Title: Characterizing hydrostatic mass bias with Mock-X

Authors: David J. Barnes (1), Mark Vogelsberger (1), Francesca A. Pearce (2), Ana-Roxana Pop (3), Rahul Kannan (3), Kaili Cao (1), Scott T. Kay (2), Lars Hernquist (3) ((1) MIT, (2) Harvard/CfA, (3) The University of Manchester)

Comments: 20 pages, 9 figures, submitted to MNRAS

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

Surveys in the next decade will deliver large samples of galaxy clusters that transform our understanding of their formation. Cluster astrophysics and cosmology studies will become systematics limited with samples of this magnitude. With known properties, hydrodynamical simulations of clusters provide a vital resource for investigating potential systematics. However, this is only realized if we compare simulations to observations in the correct way. Here we introduce the \textsc{Mock-X} analysis framework, a multiwavelength tool that generates synthetic images from cosmological simulations and derives halo properties via observational methods. We detail our methods for generating optical, Compton-$y$ and X-ray images. Outlining our synthetic X-ray image analysis method, we demonstrate the capabilities of the framework by exploring hydrostatic mass bias for the IllustrisTNG, BAHAMAS and MACSIS simulations. Using simulation derived profiles we find an approximately constant bias $b\approx0.13$ with cluster mass, independent of hydrodynamical method or subgrid physics. However, the hydrostatic bias derived from synthetic observations is mass-dependent, increasing to $b=0.3$ for the most massive clusters. This result is driven by a single temperature fit to a spectrum produced by gas with a wide temperature distribution in quasi-pressure equilibrium. The spectroscopic temperature and mass estimate are biased low by cooler gas dominating the emission, due to its quadratic density dependence. The bias and the scatter in estimated mass remain independent of the numerical method and subgrid physics. Our results are consistent with current observations and future surveys will contain sufficient samples of massive clusters to confirm the mass dependence of the hydrostatic bias.

[2]  arXiv:2001.11511 [pdf, ps, other]

Title: Scaling K2. I. Revised Parameters for 222,088 K2 Stars and a K2 Planet Radius Valley at 1.9 $R_{\oplus}$

Authors: Kevin K. Hardegree-Ullman, Jon K. Zink, Jessie L. Christiansen, Courtney D. Dressing, David R. Ciardi, Joshua E. Schlieder

Comments: 26 pages, 22 figures, 3 tables. Accepted for publication in ApJS on January 30, 2020. Machine readable versions of Tables 1 and 3 are available at this http URL (94 MB) and this http URL (190 KB)

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

Previous measurements of stellar properties for K2 stars in the Ecliptic Plane Input Catalog (EPIC; Huber et al. 2016) largely relied on photometry and proper motion measurements, with some added information from available spectra and parallaxes. Combining Gaia DR2 distances with spectroscopic measurements of effective temperatures, surface gravities, and metallicities from the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) DR5, we computed updated stellar radii and masses for 26,838 K2 stars. For 195,250 targets without a LAMOST spectrum, we derived stellar parameters using random forest regression on photometric colors trained on the LAMOST sample. In total, we measured spectral types, effective temperatures, surface gravities, metallicities, radii, and masses for 222,088 A, F, G, K, and M-type K2 stars. With these new stellar radii, we performed a simple reanalysis of 299 confirmed and 517 candidate K2 planet radii from Campaigns 1--13, elucidating a distinct planet radius valley around 1.9 $R_{\oplus}$, a feature thus far only conclusively identified with Kepler planets, and tentatively identified with K2 planets. These updated stellar parameters are a crucial step in the process toward computing K2 planet occurrence rates.

[3]  arXiv:2001.11512 [pdf, other]

Title: Testing the Reliability of Fast Methods for Weak Lensing Simulations: WL-MOKA on PINOCCHIO

Authors: Carlo Giocoli, Pierluigi Monaco, Lauro Moscardini, Tiago Castro, Massimo Meneghetti, R. Benton Metcalf, Marco Baldi

Comments: 17 pag., 17 fig., submitted to MNRAS - comments welcome

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

The generation of simulated convergence maps is of key importance in fully exploiting weak lensing by Large Scale Structure (LSS) from which cosmological parameters can be derived. In this paper we present an extension of the PINOCCHIO code which produces catalogues of dark matter haloes so that it is capable of simulating weak lensing by LSS. Like WL-MOKA, the method starts with a random realisation of cosmological initial conditions, creates a halo catalogue and projects it onto the past-light-cone, and paints in haloes assuming parametric models for the mass density distribution within them. Large scale modes that are not accounted for by the haloes are constructed using linear theory. We discuss the systematic errors affecting the convergence power spectra when Lagrangian Perturbation Theory at increasing order is used to displace the haloes within PINOCCHIO, and how they depend on the grid resolution. Our approximate method is shown to be very fast when compared to full ray-tracing simulations from an N-Body run and able to recover the weak lensing signal, at different redshifts, with a few percent accuracy. It also allows for quickly constructing weak lensing covariance matrices, complementing PINOCCHIO's ability of generating the cluster mass function and galaxy clustering covariances and thus paving the way for calculating cross covariances between the different probes. This work advances these approximate methods as tools for simulating and analysing surveys data for cosmological purposes.

[4]  arXiv:2001.11513 [pdf, other]

Title: A NICER View of Spectral and Profile Evolution for Three X-ray Emitting Millisecond Pulsars

Authors: Dominick M. Rowan, Zaynab Ghazi, Lauren Lugo, Elizabeth Spano, Andrea Lommen, Alice Harding, Christo Venter, Renee Ludlam, Paul S. Ray, Matthew Kerr, Zaven Arzoumanian, Slavko Bogdanov, Julia Deneva, Sebastien Guillot, Natalia Lewandowska, Craig B. Markwardt, Scott Ransom, Teruaki Enoto, Kent S. Wood, Keith Gendreau

Comments: 16 pages, 13 figures, accepted for publication in ApJ

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

We present two years of Neutron star Interior Composition Explorer (NICER) X-ray observations of three energetic rotation-powered millisecond pulsars (MSPs): PSRs B1937+21, B1821-24, and J0218+4232. We fit Gaussians and Lorentzians to the pulse profiles for different energy sub-bands of the soft X-ray regime to measure the energy dependence of pulse separation and width. We find that the separation between pulse components of PSR J0218+4232 decreases with increasing energy at $\gt 3\sigma$ confidence. The 95% upper limit on pulse separation evolution for PSRs B1937+21 and B1821-24 is less than 2 milliperiods per keV. Our phase-resolved spectral results provide updated constraints on the non-thermal X-ray emission of these three pulsars. The photon indices of the modeled X-ray emission spectra for each pulse component of PSR B1937+21 are inconsistent with each other at the 90% confidence level, suggesting different emission origins for each pulse. We find that the PSR B1821-24 and PSR J0218+4232 emission spectra are invariant with phase at the 90% confidence level. We describe the implications of our profile and spectral results in the context of equatorial current sheet emission models for these three MSPs with non-thermal, magnetospheric X-ray emission.

[5]  arXiv:2001.11515 [pdf, other]

Title: Scaling K2. II. Assembly of a Fully Automated C5 Planet Candidate Catalog Using EDI-Vetter

Authors: Jon K. Zink, Kevin K. Hardegree-Ullman, Jessie L. Christiansen, Courtney D. Dressing, Ian J. M. Crossfield, Erik A. Petigura, Joshua E. Schlieder, David R. Ciardi

Comments: 28 pages, 11 figures, and 3 data files. Accepted for publication in AJ

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

We present a uniform transiting exoplanet candidate list for Campaign 5 of the K2 mission. This catalog contains 75 planets with 7 multi-planet systems (5 double, 1 triple, and 1 quadruple planet system). Within the range of our search, we find 8 previously undetected candidates with the remaining 66 candidates overlapping 51% of the Kruse et al. study that manually vet Campaign 5 candidates. In order to vet our potential transit signals, we introduce the Exoplanet Detection Identification Vetter (EDI-Vetter), which is a fully automated program able to determine if a transit signal should be labeled as a false positive or a planet candidate. This automation allows us to create a statistically uniform catalog, ideal for planet occurrence rate measurements. When tested, the vetting software is able to ensure our sample is 94.2% reliable against systematic false positives. Additionally, we inject artificial transits at the light-curve-level of the raw K2 data and find the maximum completeness of our pipeline is 70% before vetting and 60% after vetting. For convenience of future occurrence rate studies, we include measurements of stellar noise (CDPP) and the three-transit window function for each target. This study is part of a larger survey of the K2 data set and the methodology which will be applied to the entirety of the K2 data set.

[6]  arXiv:2001.11517 [pdf, ps, other]

Title: Detecting Helium Reionization with Fast Radio Bursts

Authors: Eric V. Linder

Comments: 8 pages, 8 figures

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

Fast radio bursts (FRB) probe the electron density of the universe along the path of propagation, making high redshift FRB sensitive to the helium reionization epoch. We analyze the signal to noise with which a detection of the amplitude of reionization can be made, and its redshift, for various cases of future FRB survey samples, assessing survey characteristics including total number, redshift distribution, peak redshift, redshift depth, and number above the reionization redshift, as well as dependence on reionization redshift. We take into account scatter in the dispersion measure due to an inhomogeneous intergalactic medium (IGM) and uncertainty in the FRB host and environment dispersion measure, as well as cosmology. For a future survey with 500 FRB extending out to $z=5$, and a sudden reionization, the signal to noise for helium reionization detection can approach $5\sigma$ and the reionization redshift be determined to $\sigma(z_r)\approx0.24$ in an optimistic scenario, or $2\sigma$ and $\sigma(z_r)\approx0.34$ taking into account further uncertainties on IGM fraction evolution and redshift uncertainties.

[7]  arXiv:2001.11518 [pdf, other]

Title: The Three Hundred Project: Backsplash galaxies in simulations of clusters

Authors: Roan Haggar, Meghan E. Gray, Frazer R. Pearce, Alexander Knebe, Weiguang Cui, Robert Mostoghiu, Gustavo Yepes

Comments: 13 pages, 12 figures, accepted for publication in MNRAS

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

In the outer regions of a galaxy cluster, galaxies may be either falling into the cluster for the first time, or have already passed through the cluster centre at some point in their past. To investigate these two distinct populations, we utilise TheThreeHundred project, a suite of 324 hydrodynamical resimulations of galaxy clusters. In particular, we study the 'backsplash population' of galaxies; those that have passed within $R_{200}$ of the cluster centre at some time in their history, but are now outside of this radius. We find that, on average, over half of all galaxies between $R_{200}$ and $2R_{200}$ from their host at $z=0$ are backsplash galaxies, but that this fraction is dependent on the dynamical state of a cluster, as dynamically relaxed clusters have a greater backsplash fraction. We also find that this population is mostly developed at recent times ($z\leq0.4$), and is dependent on the recent history of a cluster. Finally, we show that the dynamical state of a given cluster, and thus the fraction of backsplash galaxies in its outskirts, can be predicted based on observational properties of the cluster.

[8]  arXiv:2001.11519 [pdf, other]

Title: The OTELO survey. I. Description, data reduction, and multi-wavelength catalogue

Authors: Ángel Bongiovanni, Marina Ramón-Pérez, Ana Mará Pérez García, Jordi Cepa, Miguel Cerviño, Jakub Nadolny, Ricardo Pérez Martínez, Emilio J. Alfaro Navarro, Héctor O. Castañeda, José Antonio de Diego, Alessandro Ederoclite, Mirian Fernández-Lorenzo, Jesús Gallego, J. Jesús González, J. Ignacio González-Serrano, Maritza A. Lara-López, Iván Oteo Gómez, Carmen P. Padilla Torres, I. Pintos-Castro, Mirjana Pović, Miguel Sánchez-Portal, D. Heath Jones, Joss Bland-Hawthorn, Antonio Cabrera-Lavers

Comments: 29 pages, 29 figures. Published in Astronomy \& Astrophysics

Journal-ref: A&A, 631A (2019), 9B

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

The evolution of galaxies through cosmic time is studied observationally by means of extragalactic surveys. The OTELO survey aims to provide the deepest narrow-band survey to date in terms of minimum detectable flux and emission line equivalent width in order to detect the faintest extragalactic emission line systems. In this way, OTELO data will complements other broad-band, narrow-band, and spectroscopic surveys. The red tunable filter of the OSIRIS instrument on the 10.4 m Gran Telescopio Canarias (GTC) is used to scan a spectral window centred at $9175 \AA$, which is free from strong sky emission lines, with a sampling interval of $6 \AA$ and a bandwidth of $12 \AA$ in the most deeply explored Extended Groth Strip region. Careful data reduction using improved techniques for sky ring subtraction, accurate astrometry, photometric calibration, and source extraction enables us to compile the OTELO catalogue. This catalogue is complemented with ancillary data ranging from deep X-ray to far-infrared, including high resolution HST images, which allow us to segregate the different types of targets, derive precise photometric redshifts, and obtain the morphological classification of the extragalactic objects detected. The OTELO multi-wavelength catalogue contains 11237 entries and is 50\% complete at AB magnitude 26.38. Of these sources, 6600 have photometric redshifts with an uncertainty $z_{phot}$ better than $0.2 (1+z_{phot})$. A total of 4336 of these sources correspond to preliminary emission line candidates, which are complemented by 81 candidate stars and 483 sources that qualify as absorption line systems. The OTELO survey products were released to the public on 2019.

[9]  arXiv:2001.11521 [pdf, ps, other]

Title: High Resolution Spectral Line Indices Useful for the Analysis of Stellar Populations

Authors: Lino H. Rodriguez-Merino (1), Y. D. Mayya (1), Paula R. T. Coelho (2), Gustavo Bruzual (3), Stephane Charlot (4), Esperanza Carrasco (1), Armando Gil de Paz (5) ((1) Instituto Nacional de Astrofisica, Optica y Electronica, (2) Universidad de Sao Paulo, Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, (3) Instituto de Radioastronomia y Astrofisica, UNAM, (4) Sorbonne Universite, CNRS, Institut d'Astrophysique de Paris, (5) Universidad Complutense de Madrid, Departamento de Fisica de la Tierra y Astrofisica, Instituto de Fisica de Particulas y del Cosmos)

Comments: To be published in The Astrophysical Journal Letters

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

The well-known age-metallicity-attenuation degeneracy does not permit unique and good estimates of basic parameters of stars and stellar populations. The effects of dust can be avoided using spectral line indices, but current methods have not been able to break the age-metallicity degeneracy. Here we show that using at least two new spectral line indices defined and measured on high-resolution (R= 6000) spectra of a signal-to-noise ratio (S/N) > 10 one gets unambiguous estimates of the age and metallicity of intermediate to old stellar populations. Spectroscopic data retrieved with new astronomical facilities, e.g., X-shooter, MEGARA, and MOSAIC, can be employed to infer the physical parameters of the emitting source by means of spectral line index and index--index diagram analysis.

[10]  arXiv:2001.11525 [pdf, ps, other]

Title: Asteroseismology of evolved stars to constrain the internal transport of angular momentum II. Test of a revised prescription for transport by the Tayler instability

Authors: P. Eggenberger, J.W. den Hartogh, G. Buldgen, G. Meynet, S.J.A.J. Salmon, S. Deheuvels

Comments: 5 pages, 5 figures, published in A&A

Journal-ref: 2019, A&A 631, L6

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

Context: Asteroseismic measurements reveal that an unknown efficient angular momentum (AM) transport mechanism is needed for subgiant and red giant stars. A revised prescription for AM transport by the magnetic Tayler instability has been recently proposed as a possible candidate for such a missing mechanism.
Results: The revised prescription for the transport by the Tayler instability leads to low core rotation rates after the main sequence that are in better global agreement with asteroseismic measurements than those predicted by models with purely hydrodynamic processes or with the original Tayler-Spruit dynamo. A detailed comparison with asteroseismic data shows that the rotational properties of at most two of the six subgiants can be correctly reproduced by models accounting for this revised magnetic transport process. This result is obtained independently of the value adopted for the calibration parameter in this prescription. We also find that this transport by the Tayler instability faces difficulties in simultaneously reproducing asteroseismic measurements available for subgiant and red giant stars. The low values of the calibration parameter needed to correctly reproduce the rotational properties of two of the six subgiants lead to core rotation rates during the red giant phase that are too high. Inversely, the higher values of this parameter needed to reproduce the core rotation rates of red giants lead to a very low degree of radial differential rotation before the red giant phase, which is in contradiction with the internal rotation of subgiant stars.
Conclusions: In its present form, the revised prescription for the transport by the Tayler instability does not provide a complete solution to the missing AM transport revealed by asteroseismology of evolved stars.

[11]  arXiv:2001.11532 [pdf, other]

Title: On the use of the first-order moment approach for measurements of H_eff from LSD profiles

Authors: J.C. Ramírez Vélez

Comments: ACCEPTED for publication in MNRAS

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

The big majority of the reported measurements of the stellar magnetic fields that have analysed spectropolarimetric data have employed the least-square-deconvolution method (LSD) and the first-order moment approach. We present a series of numerical tests in which we review some important aspects of this technique. First, we show that the selection of the profile widths, i.e. integration range in the first-order moment equation, is independent of the accuracy of the magnetic measurements, meaning that for any arbitrary profile width it is always possible to properly determine the longitudinal magnetic field. We also study the interplay between the line depth limit adopted in the line mask and the normalisation values of the LSD profiles. We finally show that the rotation of the stars has to be considered to correctly infer the intensity of the magnetic field, something that has been neglected up to now. We show that the latter consideration is crucial, and our test shows that the magnetic intensities differ by a factor close to 3 for a moderate fast rotator star with vsini of 50 km/s. Therefore, it is expected that in general the stellar magnetic fields reported for fast rotators are stronger than what was believed. All the previous results shows that the first-order moment can be a very robust tool for measurements of magnetic fields, provided that the weak magnetic field approximation is secured. We also show that when the magnetic field regime breaks down, the use of the first-order moment method becomes uncertain.

[12]  arXiv:2001.11540 [pdf, other]

Title: Thermal Convection in Stars and in Their Atmosphere

Authors: Friedrich Kupka

Comments: 42 pages, 2 figures, proceedings of the Evry Schatzman School 2018. Editors: M. Rieutord, I. Baraffe, Y. Lebreton. Preprint of author accepted manuscript as submitted to EDP Sciences Proceedings (see this https URL )

Journal-ref: Multi-Dimensional Processes in Stellar Physics, EDP Sciences Proceedings (2020), pp. 69-110

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

Thermal convection is one of the main mechanisms of heat transport and mixing in stars in general and also in the photospheric layers which emit the radiation that we observe with astronomical instruments. The present lecture notes first introduce the role of convection in astrophysics and explain the basic physics of convection. This is followed by an overview on the modelling of convection. Challenges and pitfalls in numerical simulation based modelling are discussed subsequently. Finally, a particular application for the previously introduced concepts is described in more detail: the study of convective overshooting into stably stratified layers around convection zones in stars.

[13]  arXiv:2001.11556 [pdf, other]

Title: On the Comparison of AGN with GRMHD Simulations: I. Sgr A*

Authors: Richard Anantua, Sean Ressler, Eliot Quataert

Comments: 16 pages, 14 figures

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

We present models of Galactic Center emission in the vicinity of Sagittarius A* that use parametrizations of the electron temperature or energy density. These models include those inspired by two-temperature general relativistic magnetohydrodynamic (GRMHD) simulations as well as jet-motivated prescriptions generalizing equipartition of particle and magnetic energies. From these models, we calculate spectra and images and classify them according to their distinct observational features. Some models produce morphological and spectral features, e.g., image sizes, the sub-mm bump and low frequency spectral slope compatible with observations. Models with spectra consistent with observations produce the most compact images, with the most prominent, asymmetric photon rings. Limb brightened outflows are also visible in many models. Of all the models we consider, that which represents the current data the best is one in which electrons are relativistically hot when magnetic pressure is larger than the thermal pressure, but cold (i.e., negligibly contributing to the emission) otherwise. This work is part of a series also applying the "observing" simulations methodology to near-horizon regions of supermassive black holes in M87 and 3C 279.

[14]  arXiv:2001.11564 [pdf, other]

Title: Snakes on a Plane: do Milky Way stellar streams and globular clusters align in a Vast Polar Structure?

Authors: Alexander H. Riley, Louis E. Strigari

Comments: 10+7 pages, 4 figures, 4+5 tables. Submitted to MNRAS

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

There is increasing evidence that a substantial fraction of Milky Way satellite galaxies align in a rotationally-supported plane of satellites, a rare configuration in cosmological simulations of galaxy formation. It has been suggested that other Milky Way substructures (namely young halo globular clusters and stellar/gaseous streams) similarly tend to align with this plane, accordingly dubbed the Vast Polar Structure (VPOS). Using systemic proper motions inferred from Gaia data, we find that globular cluster orbital poles are not clustered in the VPOS direction, though the population with the highest VPOS membership fraction is the young halo clusters (~30%). We additionally provide a current census of stellar streams, including new streams discovered using the Dark Energy Survey and Gaia datasets, and find that stellar stream normals are also not clustered in the direction of the VPOS normal. We also find that, based on orbit modeling, there is a likely association between NGC 3201 and the Gj\"{o}ll stellar stream and that, based on its orbital pole, NGC 4147 is likely not a Sagittarius globular cluster. That the Milky Way's accreted globular clusters and streams do not align in the same planar configuration as its satellites suggests that the plane of satellites is either a particularly stable orbital configuration or a population of recently accreted satellites. Neither of these explanations is particularly likely in light of other recent studies, leaving the plane of satellites problem as one of the more consequential open problems in galaxy formation and cosmology.

[15]  arXiv:2001.11573 [pdf, other]

Title: Putting binning in the bin: strong evidence for a continuous relationship between galaxy starburstiness and AGN power

Authors: L. P. Grimmett, J. R. Mullaney, E. P. Bernhard, C. M. Harrison, D. M. Alexander, F. Stanley, V. A. Masoura, K. Walters

Comments: 11 pages, 4 figures, submitted to MNRAS, comments welcome

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

Studies investigating the relationship between star formation rate (SFR) and AGN power often rely on averaging techniques -- such as stacking -- to incorporate information from non-detections. However, averages, and especially means, can be strongly affected by outliers and can therefore give a misleading indication of the "typical" case. Recently, a number of studies have taken a step further by binning their sample in terms of AGN power, and investigating how the SFR distribution differs between these bins. These bin thresholds are often weakly motivated, and binning implicitly assumes that sources within the same bin have similar (or even identical) properties. In this paper, we investigate whether the main sequence-normalised SFR (i.e., starburstiness, $R_{\rm MS}$) distribution changes continuously as a function of AGN power, using a hierarchical Bayesian model that completely removes the need to bin. In doing so, we find strong evidence that the $R_{\rm MS}$ distribution changes with AGN power, such that higher X-ray luminosity AGNs have a tighter physical connection to the star forming process than lower luminosity AGNs.

[16]  arXiv:2001.11605 [pdf, other]

Title: Interstellar comet 2I/Borisov as seen by MUSE: C$_2$, NH$_2$ and red CN detections

Authors: Michele T. Bannister, Cyrielle Opitom, Alan Fitzsimmons, Youssef Moulane, Emmanuel Jehin, Darryl Seligman, Philippe Rousselot, Matthew M. Knight, Michael Marsset, Megan E. Schwamb, Aurélie Guilbert-Lepoutre, Laurent Jorda, Pierre Vernazza, Zouhair Benkhaldoun

Comments: 5 figures. Submitted to AAS Journals

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

We report the clear detection of C$_2$ and of abundant NH$_2$ in the first prominently active interstellar comet, 2I/Borisov. We observed 2I on three nights in November 2019 at optical wavelengths 4800--9300 \AA with the Multi-Unit Spectroscopic Explorer (MUSE) integral-field spectrograph on the ESO/Very Large Telescope. These data, together with observations close in time from both 0.6-m TRAPPIST telescopes, provide constraints on the production rates of species of gas in 2I's coma. From the MUSE detection on all epochs of several bands of the optical emission of the C$_2$ Swan system, a rich emission spectrum of NH$_2$ with many highly visible bands, and the red (1-0) bandhead of CN, together with violet CN detections by TRAPPIST, we infer production rates of $Q$(C$_2$) = $1.1\times10^{24}$ mol s$^{-1}$, $Q$(NH$_2$) = $4.8\times10^{24}$ mol s$^{-1}$ and $Q$(CN) = $(1.8\pm0.2)\times 10^{24}$ mol s$^{-1}$. In late November at 2.03~au, 2I had a production ratio of C$_2$/CN$=0.61$, only barely carbon-chain depleted, in contrast to earlier reports measured further from the Sun of strong carbon-chain depletion. Thus, 2I has shown evolution in its C$_2$ production rate: a parent molecule reservoir has started sublimating. At $Q$(NH$_2$)/$Q$(CN) = 2.7, this second interstellar object is enriched in NH$_2$, relative to the known Solar System sample.

[17]  arXiv:2001.11646 [pdf, other]

Title: Thermal simulations of temperature excursions on the Athena X-IFU detector wafer from impacts by cosmic rays

Authors: Samantha Lynn Stever, Philippe Peille, Marcel Bruijn, Abdellah Roussafi, Simone Lotti, Claudio Macculi, Reinier Janssen, Roland den Hartog

Comments: accepted for publication in the Journal of Low Temperature Physics

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

We present the design and implementation of a thermal model, developed in COMSOL, aiming to probe the wafer-scale thermal response arising from realistic rates and energies of cosmic rays at L2 impacting the detector wafer of Athena X-IFU. The wafer thermal model is a four-layer 2D model, where 2 layers represent the constituent materials (Si bulk and Si$_{3}$N$_{4}$ membrane), and 2 layers represent the Au metallization layer's phonon and electron temperatures. We base the simulation geometry on the current specifications for the X-IFU detector wafer, and simulate cosmic ray impacts using a simple power injection into the Si bulk. We measure the temperature at the point of the instrument's most central TES detector. By probing the response of the system and pulse characteristics as a function of the thermal input energy and location, we reconstruct cosmic ray pulses in Python. By utilizing this code, along with the results of the GEANT4 simulations produced for X-IFU, we produce realistic time-ordered data (TOD) of the temperature seen by the central TES, which we use to simulate the degradation of the energy resolution of the instrument in space-like conditions on this wafer. We find a degradation to the energy resolution of 7 keV X-rays of $\approx$0.04 eV. By modifying wafer parameters and comparing the simulated TOD, this study is a valuable tool for probing design changes on the thermal background seen by the detectors.

[18]  arXiv:2001.11675 [pdf, other]

Title: Molecular Oxygen in the nearest QSO Mrk 231

Authors: Junzhi Wang, Di Li, Paul F. Goldsmith, Zhi-Yu Zhang, Yu Gao, Yong Shi, Shanghuo Li, Min Fang, Juan Li, Jiangshui Zhang

Comments: 11 pages, 5 figures, published in ApJ

Journal-ref: ApJ 889 129 (2020)

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

We report the detection of an emission feature at the 12 sigma level with FWHM line width of about 450 km/s toward the nearest quasi-stellar object, QSO Mrk 231. Based on observations with the IRAM 30 m telescope and the NOEMA Interferometer, the 11-10 transition of molecular oxygen is the likely origin of line with rest frequency close to 118.75 GHz. The velocity of the O2 emission in Mrk 231 coincides with the red wing seen in CO emission, suggesting that it is associated with the outflowing molecular gas, located mainly at about ten kpc away from the central AGN. This first detection of extragalactic molecular oxygen provides an ideal tool to study AGN-driven molecular outflows on dynamic time scales of tens of Myr. O2 may be a significant coolant for molecular gas in such regions affected by AGN-driven outflows. New astrochemical models are needed to explain the implied high molecular oxygen abundance in such regions several kpc away from the center of galaxies.

[19]  arXiv:2001.11680 [pdf, other]

Title: A catalog of Galactic multiple systems with a red supergiant and a B star

Authors: M. Pantaleoni González, J. Maíz Apellániz, R. H. Barbá, I. Negueruela

Comments: Table with 108 objects included

Journal-ref: RNAAS 4 (2020) 12

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

Binary systems composed of a red supergiant and a B star are useful probes of stellar evolution. We have searched the literature to create a catalog of 108 Galactic systems of such type, which is presented here.

[20]  arXiv:2001.11681 [pdf, other]

Title: A catalogue of H$α$ emission-line point sources in the vicinity fields of M31 and M33 from the LAMOST survey

Authors: M. Zhang, B.-Q. Chen, Z.-Y. Huo, H.-W. Zhang, M.-S. Xiang, H.-B. Yuan, Y. Huang, C. Wang, X.-W. Liu

Comments: 11 pages, 8 figures, 2 tables, RAA in press

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

We present a catalogue of 3,305 H$\alpha$ emission-line point sources observed with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) in the vicinity fields of M31 and M33 during September 2011 and January 2016. The catalogue contains 1,487 emission-line stars, 532 emission-line nebulae including 377 likely planetary nebulae (PNe), 83 H~{\textsc{ii}} regions candidates and 20 possible supernovae remnants (SNRs) and 1,286 unknown objects. Among them, 24 PN candidates, 19 H~{\sc ii} region candidates, 10 SNR candidates and 1 symbiotic star candidate are new discoveries. Radial velocities and fluxes estimated from the H$\alpha$ line and those quantities of seven other major emission lines including H$\beta$, [O~{\textsc{iii}}]~$\lambda$4959, [O~{\textsc{iii}}]~$\lambda$5007, [N~{\textsc{ii}}]~$\lambda$6548, [N~{\textsc{ii}}]~$\lambda$6583, [S~{\textsc{ii}}]~$\lambda$6717 and [S~{\textsc{ii}}]~$\lambda$6731 lines of all the catalogued sources yielded from the LAMOST spectra are also presented in our catalogue. Our catalogue is an ideal starting point to study the chemistry properties and kinematics of M31 and M33.

[21]  arXiv:2001.11682 [pdf, other]

Title: A large catalogue of molecular clouds with accurate distances within 4 kpc of the Galactic disk

Authors: B.-Q. Chen, G.-X. Li, H.-B. Yuan, Y. Huang, Z.-J. Tian, H.-F. Wang, H.-W. Zhang, C. Wang, X.-W. Liu

Comments: 11 pages, 7 figures, 2 tables, MNRAS in press

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

We present a large, homogeneous catalogue of molecular clouds within 4 kpc from the Sun at low Galactic latitudes ($|b|$ $<$ 10\degr) with unprecedented accurate distance determinations. Based on the three-dimensional dust reddening map and estimates of colour excesses and distances of over 32 million stars presented in Chen et al, we have identified 567 dust/molecular clouds with a hierarchical structure identification method and obtained their distance estimates by a dust model fitting algorithm. The typical distance uncertainty is less than 5 per cent. As far as we know, this is the first large catalogue of molecular clouds in the Galactic plane with distances derived in a direct manner. The clouds are seen to lie along the Sagittarius, Local and Perseus Arms. In addition to the known structures, we propose the existence of a possible {\it spur}, with a pitch angle of about 34\degr, connecting the Local and the Sagittarius Arms in the fourth quadrant. We have also derived the physical properties of those molecular clouds. The distribution of cloud properties in different parameter spaces agrees grossly with the previous results. Our cloud sample is an ideal starting point to study the concentration of dust and gas in the solar vicinity and their star formation activities.

[22]  arXiv:2001.11689 [pdf, other]

Title: Alleviating the tension in CMB using Planck-scale Physics

Authors: Abhay Ashtekar, Brajesh Gupt, Donghui Jeong, V. Sreenath

Comments: 6 pages, 5 figures, 1 table

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

Certain anomalies in the CMB bring out a tension between the six-parameter flat $\Lambda$CDM model and the CMB data. We revisit the PLANCK analysis with loop quantum cosmology (LQC) predictions and show that LQC alleviates both the large-scale power anomaly and the tension in the lensing amplitude. These differences arise because, in LQC, the primordial power spectrum is scale dependent for small $k$, with a specific power suppression. We conclude with a prediction of larger optical depth and power suppression in the B-mode polarization power spectrum on large scales.

[23]  arXiv:2001.11702 [pdf, ps, other]

Title: CME Productive and Non-productive Recurring Jets Near an Active Region AR11176

Authors: Ritika Solanki, Abhishek K. Srivastava, Bhola N. Dwivedi

Comments: 25 Pages, 15 figures, 1 table, Accepted for publication in Solar Physics

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

We study the recurring jets near AR11176 during the period 2011 March 31 17:00 UT to April 1 05:00 UT using observations from the Atmospheric Imaging Assembly (AIA) on board Solar Dynamics Observatory (SDO). Mini-filaments (mini-filament1 & 2) are found at the base of these recurring jets where mini-filament1 shows the partial signature of eruption in case of Jet1-3. However, the mini-filament2 shows a complete eruption driving a full blow-out jet (Jet4). The eruption of mini-filament2 triggers C-class flare and Jet4 eruption. The eruption of Jet4 triggers a coronal mass ejection (CME). The plane-of-sky velocity of recurring jets (Jet1-4) results in 160 km/s, 106 km/s, 151 km/s and 369 km/s. The estimated velocity of CME is 636 km/s. The continuous magnetic flux cancellation is observed at the base of the jet productive region which could be the cause of the eruption of mini-filaments and recurring jets. In the former case, the mini-filament1 shows partial eruption and first three jets (Jet1-3) are produced, but the rate of cancellation was rather low. However, in the latter case, mini-filament2 fully erupts (perhaps because of a higher cancellation rate), and this triggers a C-class flare and a CME-productive jet. At the base of first three jets (Jet1-3), the mini-filament1 causes to push the overlying dynamic complex thin loops resulting in the reconnection and drives the jet (Jet1-3) eruptions. The formation of the plasma blobs are observed during the eruption of the first jet (Jet1).

[24]  arXiv:2001.11716 [pdf, other]

Title: Point Spread Function Modelling for Wide Field Small Aperture Telescopes with a Denoising Autoencoder

Authors: Peng Jia, Xiyu Li, Zhengyang Li, Weinan Wang, Dongmei Cai

Comments: 10 pages, 10 figures, Accpeted after minor revision by MNRAS

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Machine Learning (cs.LG); Image and Video Processing (eess.IV)

The point spread function reflects the state of an optical telescope and it is important for data post-processing methods design. For wide field small aperture telescopes, the point spread function is hard to model, because it is affected by many different effects and has strong temporal and spatial variations. In this paper, we propose to use the denoising autoencoder, a type of deep neural network, to model the point spread function of wide field small aperture telescopes. The denoising autoencoder is a pure data based point spread function modelling method, which uses calibration data from real observations or numerical simulated results as point spread function templates. According to real observation conditions, different levels of random noise or aberrations are added to point spread function templates, making them as realizations of the point spread function, i.e., simulated star images. Then we train the denoising autoencoder with realizations and templates of the point spread function. After training, the denoising autoencoder learns the manifold space of the point spread function and can map any star images obtained by wide field small aperture telescopes directly to its point spread function, which could be used to design data post-processing or optical system alignment methods.

[25]  arXiv:2001.11733 [pdf, other]

Title: AGN jets versus accretion as reionization sources

Authors: N. Torres-Albà, V. Bosch-Ramon, K. Iwasawa

Comments: 7 pages, 3 figures, accepted for publication in A&A

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

Cosmic reionization put an end to the dark ages that came after the recombination era. Observations seem to favor the scenario where massive stars generating photons in low-mass galaxies were responsible for the bulk of reionization. Even though a possible contribution from accretion disks of active galactic nuclei (AGN) has been widely considered, they are currently thought to have had a minor role in reionization. Our aim is to study the possibility that AGN contributed to reionization not only through their accretion disks, but also through ionizing photons coming from the AGN jets interacting with the IGM. We adopt an empirically derived AGN luminosity function at $z\simeq6$, use X-ray observations to correct it for the presence of obscured sources, and estimate the density of jetted AGN. We then use analytical calculations to derive the fraction of jet energy that goes into ionizing photons. Finally, we compute the contribution of AGN jets to the H II volume filling factor at redshifts $z\simeq15-5$. We show that the contribution of the AGN jet lobes to the reionization of the Universe at $z\sim6$ might have been as high as $\gtrsim 10$\% of that of star-forming galaxies, under the most favorable conditions of jetted and obscuration fraction. The contribution of AGN to the reionization, while most likely not dominant, could have been higher than previously assumed, thanks to the radiation originated in the jet lobes.

[26]  arXiv:2001.11747 [pdf, ps, other]

Title: The ambiguous transient ASASSN-17hx. A possible nova-impostor

Authors: Elena Mason, Steven N. Shore, Paul Kuin, Terry Bohlsen

Comments: accepted for publication on A&A

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

Some transients, although classified as novae based on their maximum and early decline optical spectra, cast doubts on their true nature and whether nova impostors might exist. We monitored a candidate nova which displayed a distinctly unusual light curve at maximum and early decline through optical spectroscopy (3000-10000 \AA, 500<R<100000) complemented with Swift UV and AAVSO optical photometry. We use the spectral line series to characterize the ejecta dynamics, structure, and mass. We found that the ejecta are in free ballistic expansion and structured as typical of classical novae. However, their derived mass is at least an order of magnitude larger than the typical ejecta masses obtained for classical novae. Specifically, we found M$_{ej}\simeq$9$\times$10$^{-3}$ M$_\odot$ independent of the distance for a filling factor $\varepsilon$=1. By constraining the distance we derived $\varepsilon$ in the range 0.08-0.10, giving a mass 7$\times$10$^{-4}\lesssim$ M$_{ej}\lesssim$9$\times$10$^{-4}$ M$_\odot$. The nebular spectrum, characterized by unusually strong coronal emission lines, confines the ionizing source energy to the range 20-250 eV, possibly peaking in the range 75-100 or 75-150 eV. We link this source to other slow novae which showed similar behavior and suggest that they might form a distinct physical sub-group. They may result from a classical nova explosion occurring on a very low mass white dwarf or be impostors for an entirely different type of transient.

[27]  arXiv:2001.11749 [pdf, other]

Title: Measuring stellar magnetic helicity density

Authors: K. Lund, M. Jardine, L. T. Lehmann, D. H. Mackay, V. See, A. A. Vidotto, J.-F. Donati, R. Fares, C. P. Folsom, S. V. Jeffers, S. C. Marsden, J. Morin, P. Petit

Comments: 11 pages, 7 figures

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

Helicity is a fundamental property of a magnetic field but to date it has only been possible to observe its evolution in one star - the Sun. In this paper we provide a simple technique for mapping the large-scale helicity density across the surface of any star using only observable quantities: the poloidal and toroidal magnetic field components (which can be determined from Zeeman-Doppler imaging) and the stellar radius. We use a sample of 51 stars across a mass range of 0.1-1.34 M$_\odot$ to show how the helicity density relates to stellar mass, Rossby number, magnetic energy and age. We find that the large-scale helicity density increases with decreasing Rossby number $R_o$, peaking at $R_o \simeq 0.1$, with a saturation or decrease below that. For both fully- and partially-convective stars we find that the mean absolute helicity density scales with the mean squared toroidal magnetic flux density according to the power law: $|\langle{h\,}\rangle|$ $\propto$ $\langle{\rm{B_{tor}}^2_{}\,\rangle}^{0.86\,\pm\,0.04}$. The scatter in this relation is consistent with the variation across a solar cycle, which we compute using simulations and observations across solar cycles 23 and 24 respectively. We find a significant decrease in helicity density with age.

[28]  arXiv:2001.11772 [pdf, other]

Title: Multi-wavelength observations of the BL Lac object Fermi J1544-0649: one year after its awakening

Authors: P. H. T. Tam, P. S. Pal, Y. D. Cui, N. Jiang, Y. Sotnikova, C. W. Yang, L. Z. Wang, B. T. Tang, Y. B. Li, J. Mao, A. K. H. Kong, Z. H. Zhong, J. Ding, T. Mufakharov, J. F. Fan, L. M. Dou, R. F. Shen, Y. L. Ai

Comments: Submitted in Journal of High Energy Astrophysics

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

We report observations of a transient source \fermi\ from radio to \grs. \fermi\ was discovered by the {\it Fermi-LAT} in May 2017. Follow-up {\it Swift-XRT} observations revealed three flaring episodes through March 2018, and the peak X-ray flux is about $10^3$ higher than the {\it ROSAT all-sky survey (RASS)} flux upper limit. Optical spectral measurements taken by the {\it Magellan 6.5-m telescope} and the {\it Lick-Shane telescope} both show a largely featureless spectrum, strengthening the BL Lac interpretation first proposed by \citet{Bruni18}. The optical and mid-infrared (MIR) emission goes to a higher state in 2018, when the flux in high energies goes down to a lower level. Our {\it RATAN-600m} measurements at 4.8~GHz and 8.2~GHz do not indicate any significant radio flux variation over the monitoring seasons in 2017 and 2018, nor deviate from the archival {\it NVSS} flux level. During GeV flaring times, the spectrum is very hard ($\Gamma_\gamma\sim$1.7) in the GeV band and at times also very hard (($\Gamma_{\rm X}\lesssim2$) in the X-rays, similar to a high-synchrotron-peak (or even an extreme) BL Lac object, making \fermi\ a good target for ground-based {\it Cherenkov telescopes}.

[29]  arXiv:2001.11787 [pdf, other]

Title: Statistical mass function of prestellar cores from the density distribution of their natal clouds

Authors: S. Donkov, T. V. Veltchev, Ph. Girichidis, R. S. Klessen

Comments: 12 pages, 5 figures; to appear in A&A

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

The mass function of clumps observed in molecular clouds raises interesting theoretical issues, especially in its relation to the stellar initial mass function. We propose a statistical model of the mass function of prestellar cores (CMF), formed in self-gravitating isothermal clouds at a given stage of their evolution. The latter is characterized by the mass-density probability distribution function ($\rho$-PDF), which is a power-law with slope $q$. The variety of MCs is divided in ensembles according to the PDF slope and each ensemble is represented by a single spherical cloud. The cores are considered as elements of self-similar structure typical for fractal clouds and are modeled by spherical objects populating each cloud shell. Our model assumes relations between size, mass and density of the statistical cores. Out of them a core mass-density relationship $\rho\propto m^x$ is derived where $x=1/(1+q)$. We found that $q$ determines the existence or non-existence of a threshold density for core collapse. The derived general CMF is a power law of slope $-1$ while the CMF of gravitationally unstable cores has a slope $(-1 + x/2)$, comparable with the slopes of the high-mass part of the stellar initial mass function and of observational CMFs.

[30]  arXiv:2001.11798 [pdf, other]

Title: Investigation of surface effects of simple flux tubes using numerical simulations

Authors: M. Waidele, M. Roth

Journal-ref: ApJ, 889, 83 (2020)

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

We use the SPARC code for MHD simulations with monolithic flux tubes of varying subsurface topology. Our studies involve the interactions of waves caused by a single source with subsurface magnetic fields. Mode conversion causing acoustic power to trickle downwards along the flux tube has been described before and can be visualized in our simulations. We show that this downward propagation causes the flux tube to act as an isolated source, creating a characteristic surface wavefield. Measuring this wavefield at the surface reveals subsurface properties of the magnetic field topology. Using time distance helioseismology, we demonstrate how to detect such a flux tube signal based on a group travel-time delay of $\varDelta t = 282.6$ sec due to the wave packet spending time subsurface as a slow mode wave. Although the amplitude is small and generally superimposed by the full wave field, it can be detected if assumptions about $\varDelta t$ are made. We demonstrate this for a simulation with solar like sources. This kind of study has the potential to reveal subsurface information of sunspots based on the analysis of a surface signal.

[31]  arXiv:2001.11827 [pdf, ps, other]

Title: Galactic Centre Threads as Nuclear MHD Waves

Authors: Yoshiaki Sofue

Comments: 6 pages, 8 figures, PASJ Letters in press

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

Propagation of fast-mode magnetohydrodynamic (MHD) compression waves is traced in the Galactic Center with a poloidal magnetic cylinder. MHD waves ejected from the nucleus are reflected and guided along the magnetic field, exhibiting vertically stretched fronts. The radio threads and non-thermal filaments are explained as due to tangential views of the waves driven by sporadic activity in Sgr A$^*$, or by multiple supernovae. In the latter case, the threads could be extremely deformed relics of old SNRs exploded in the nucleus.

[32]  arXiv:2001.11873 [pdf, ps, other]

Title: Simultaneous binary and asteroseismic modelling of the Kepler system KIC 10661783 with the $δ$ Scuti component

Authors: Amadeusz Miszuda, Wojciech Szewczuk, Jadwiga Daszyńska-Daszkiewicz

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

We present the results of analysis and modelling of the eclipsing binary system, KIC 10661783. The Fourier analysis of the Kepler light curve, corrected for the binary effects, reveals 750 frequency peaks in both p and g-mode regions. Those with the highest amplitudes concentrate in the range of 20-30 d$^{-1}$. To reproduce observed spectrum of frequencies we construct seismic models accounting for the mode instability. In order to obtain instabilities in the g-mode regime we modify the opacity tables data near the Z-bump. In order to reproduce system parameters, we construct evolutionary models including binary evolution.

[33]  arXiv:2001.11881 [pdf, other]

Title: LHAASO sensitivity for diffuse gamma-ray signals from the Galaxy

Authors: A.Neronov, D.Semikoz

Comments: 7 pages 5 figures

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

We estimate the sensitivity of LHAASO telescope for the large angular scale diffuse gamma-ray flux in multi-TeV - multi-PeV energy range. We discuss possible sources of the signal in this energy range including the guaranteed flux from cosmic ray interactions in the interstellar medium and possible flux from decaying dark matter. We show that LHAASO will be able to detect the diffuse cosmic ray induced gamma-ray flux up to high Galactic latitude regions thus providing firm identification of the Galactic cosmic ray component of the astrophysical neutrino signal detected by IceCube and clarification of the nature of the knee feature of the cosmic ray spectrum. Comparing the diffuse flux sensitivity with the diffuse gamma-ray flux expected from the dark matter decays, we show LHAASO will be able to detect the gamma-ray signal from dark matter particles of PeV-EeV mass decaying on the time scale up to 3e29 s.

[34]  arXiv:2001.11887 [pdf, other]

Title: Identifying Multiple Populations in M71 Using CN

Authors: Jeffrey M. Gerber, Eileen D. Friel, Enrico Vesperini

Comments: 18 pages, 10 figures

Journal-ref: AJ, 159, 50 (2020)

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

We have observed the CN features at $\sim$3800 ~\AA~ and 4120~ \AA~ as well as the CH band at $\sim$4300~\AA~ for 145 evolved stars in the Galactic globular cluster M71 using the multi-object spectrograph, Hydra, on the WIYN-3.5m telescope. We use these measurements to create two $\delta$CN indices finding that both distributions are best fit by two populations, a CN-enhanced and CN-normal. We find that 42 $\pm$ 4\% of the RGB stars in our sample are CN-enhanced. The percentage of CN-enhanced is 40 $\pm$ 13\% for the AGB and 33 $\pm$ 9\% for the HB stars, which suggests there are no missing second generation stars at these stages of stellar evolution. The two generations also separate in magnitude and color on the HB, which allows us to find the difference in He abundance between the two populations by fitting appropriate ZAHBs. The broad range of distances from the cluster's center covered by our sample allows us to study the dependence of the ratio of the number of first to second population stars on the distance from the cluster's center, and we find that this ratio does not vary radially and that the two populations are spatially mixed. Finally, we compare our identification of multiple populations with the classification based on the Na-O anti-correlation and the HST UV photometry, and we find good agreement with both methods.

[35]  arXiv:2001.11892 [pdf, other]

Title: Analysis of quasar magnitudes

Authors: David F. Crawford

Comments: 4 pages, 2 figures

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

Since their discovery the analysis of quasar magnitudes has generally required some form of evolution. Assuming that quasars do not have evolution this paper shows that they have a well-defined intrinsic magnitude distribution that is independent of cosmological models. However the average apparent magnitudes are essentially constant which means that the only cosmological information they contain is that the absolute flux density has a power law distribution. Thus quasar magnitudes, by themselves, are essentially useless for cosmological investigations.

[36]  arXiv:2001.11907 [pdf, ps, other]

Title: Rotational spectroscopy of singly $^{13}$C substituted isotopomers of propyne and determination of a semi-empirical equilibrium structure

Authors: Holger S. P. Müller, Sven Thorwirth, Frank Lewen

Comments: 10 pages; J. Mol. Struct., in press

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Astrophysics of Galaxies (astro-ph.GA); Atomic and Molecular Clusters (physics.atm-clus)

Submillimeter spectra of three isotopomers of propyne containing one $^{13}$C atom were recorded in natural isotopic composition in the region of 426 GHz to 785 GHz. Additional measurements were carried out near 110 GHz. Combining these with earlier data resulted in greatly improved spectroscopic parameters which permit reliable extrapolations up to about 1.5 THz. Coupled cluster quantum-chemical calculations were carried out in order to assess the differences between equilibrium and ground state rotational parameters of these and many other isotopic species to evaluate semi-empirical equilibrium structural parameters. In addition, we estimated the main spectroscopic parameters of the isotopomers of propyne with two $^{13}$C atoms, which have not yet been studied in the laboratory, but which may be detectable in astronomical sources with a large amount of $^{13}$C compared to the dominant $^{12}$C.

[37]  arXiv:2001.11975 [pdf, other]

Title: Timing the earliest quenching events with a robust sample of massive quiescent galaxies at 2 < z < 5

Authors: A. C. Carnall, S. Walker, R. J. McLure, J. S. Dunlop, D. J. McLeod, F. Cullen, V. Wild, R. Amorin, M. Bolzonella, M. Castellano, A. Cimatti, O. Cucciati, A. Fontana, A. Gargiulo, B. Garilli, M. J. Jarvis, L. Pentericci, L. Pozzetti, G. Zamorani, A. Calabro, N. P. Hathi, A. M. Koekemoer

Comments: 14 pages, 8 figures, MNRAS submitted

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

We present a sample of 151 massive ($M_* > 10^{10}\mathrm{M_\odot}$) quiescent galaxies at $2 < z < 5$, based on a sophisticated Bayesian spectral energy distribution fitting analysis of the CANDELS UDS and GOODS-South fields. Our sample includes a robust sub-sample of 61 objects for which we confidently exclude low-redshift and star-forming solutions. We identify 10 robust objects at $z>3$, of which 2 are at $z>4$. We report formation redshifts, demonstrating that the oldest objects formed at $z > 6$, however individual ages from our photometric data have significant uncertainties, typically $\sim0.5$ Gyr. We demonstrate that the UVJ colours of the quiescent population evolve with redshift at $z>3$, becoming bluer and more similar to post-starburst galaxies at lower redshift. Based upon this we construct a model for the time-evolution of quiescent galaxy UVJ colours, concluding that the oldest objects are consistent with forming the bulk of their stellar mass at $z\sim6-7$ and quenching at $z\sim5$. We report spectroscopic redshifts for two of our objects at $z=3.440$ and $3.396$, which exhibit extremely weak Ly$\alpha$ emission in ultra-deep VANDELS spectra. We calculate star-formation rates based on these line fluxes, finding that these galaxies are consistent with our quiescent selection criteria, provided their Ly$\alpha$ escape fractions are $>3$ and $>10$ per cent respectively. We finally report that our highest-redshift robust object exhibits a continuum break at $\lambda\sim7000$A in a spectrum from VUDS, consistent with our photometric redshift of $z_\mathrm{phot}=4.72^{+0.06}_{-0.04}$. If confirmed this object would be the highest-redshift known quiescent galaxy. In order to obtain stronger constraints on the times of the earliest quenching events, high-SNR spectroscopy must be extended to $z\gtrsim3$ quiescent objects.

[38]  arXiv:2001.12007 [pdf, other]

Title: Tracing the anemic stellar halo of M101

Authors: In Sung Jang, Roelof S. de Jong, Benne W. Holwerda, Antonela Monachesi, Eric F. Bell, Jeremy Bailin

Comments: 20 pages, 17 figures, accepted for publication in A&A

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

Models of galaxy formation in a cosmological context predict that massive disk galaxies should have structured extended stellar halos. Recent studies in integrated light, however, report a few galaxies, including the nearby disk galaxy M101, that have no measurable stellar halos to the detection limit. We aim to quantify the stellar content and structure of M101's outskirts by resolving its stars. We present the photometry of its stars based on deep F606W and F814W images taken with Hubble Space Telescope as part of the GHOSTS survey. The constructed CMDs of stars reach down to two magnitudes below the tip of the red giant branch. We derived radial number density profiles of the bright red giant branch (RGB) stars. The mean color of the RGB stars at $R \sim$ 40 -- 60 kpc is similar to those of metal-poor globular clusters in the Milky Way. We also derived radial surface brightness profiles using the public image data provided by the Dragonfly team. Both the radial number density and surface brightness profiles were converted to radial mass density profiles and combined. We find that the mass density profiles show a weak upturn at the very outer region, where surface brightness is as faint as $\mu_g\approx 34$ mag arcsec$^{-1}$. An exponential disk + power-law halo model on the mass density profiles finds the total stellar halo mass of $M_{halo}=8.2_{-2.2}^{+3.5}\times 10^7M_\odot$. The total stellar halo mass does not exceed $M_{halo} = 3.2 \times 10^8$ $M_{\odot}$ when strongly truncated disk models are considered. Combining the halo mass with the total stellar mass of M101, we obtain the stellar halo mass fraction of $M_{halo}/M_{gal} = 0.20_{-0.08}^{+0.10}\%$ with an upper limit of 0.78\%. We compare the halo properties of M101 with those of six GHOSTS survey galaxies as well as the Milky Way and M31 and find that M101 has an anemic stellar halo.

[39]  arXiv:2001.12009 [pdf, other]

Title: Distance mapping applied to four well-known planetary nebulae and a nova shell

Authors: Sebastian Gómez-Gordillo, Stavros Akras, Denise R. Gonçalves, Wolfgang Steffen

Comments: 16 pages, 9 figures, 5 tables. Accepted for publication in MNRAS

Journal-ref: 2020MNRAS.tmp...66G

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

Accurate distance estimates of astrophysical objects such as planetary nebulae (PNe), and nova and supernova remnants, among others, allow us to constrain their physical characteristics, such as size, mass, luminosity, and age. An innovative technique based on the expansion parallax method, the so-called distance mapping technique (DMT), provides distance maps of expanding nebulae as well as an estimation of their distances. The DMT combines the tangential velocity vectors obtained from 3D morpho-kinematic models and the observed proper motion vectors to estimate the distance. We applied the DMT to four PNe (NGC 6702, NGC 6543, NGC 6302, and BD+30 3639) and one nova remnant (GK Persei) and derived new distances in good agreement with previous studies. New simple morpho-kinematic shape models were generated for NGC 6543, NGC 6302, and NGC 6702, whereas for BD+30 3639 and GK Persei published models were used. We demonstrate that the DMT is a useful tool to obtain distance values of PNe, in addition to revealing kinematically peculiar regions within the nebulae. Distances are also derived from the trigonometric Gaia parallaxes. The effect of the non-negligible parallax offset in the second Gaia data release is also discussed.

Cross-lists for Mon, 3 Feb 20

[40]  arXiv:2001.11559 (cross-list from hep-ph) [pdf, other]

Title: DES16C3cje: A low-luminosity, long-lived supernova

Authors: C. P. Gutiérrez, M. Sullivan, L. Martinez, M. C. Bersten, C. Inserra, M. Smith, J. P. Anderson, Y.-C. Pan, A. Pastorello, L. Galbany, P. Nugent, C. R. Angus, C. Barbarino, T.-W. Chen, T. M. Davis, M. Della Valle, R. J. Foley, M. Fraser, C. Frohmaier, S. González-Gaitán, G. F. Lewis, M. Gromadzki, E. Kankare, R. Kokotanekova, J. Kollmeier, M. R. Magee, K. Maguire, A. Möller, N. Morrell, M. Nicholl, M. Pursiainen, J. Sollerman, N. E. Sommer, E. Swann, B. E. Tucker, P. Wiseman, M. Aguena, S. Allam, S. Avila, E. Bertin, D. Brooks, E. Buckley-Geer, D. L. Burke, A. Carnero Rosell, M. Carrasco Kind, J. Carretero, M. Costanzi, L. N. da Costa, J. De Vicente, S. Desai, H. T. Diehl, P. Doel, T. F. Eifler, B. Flaugher, P. Fosalba, J. Frieman, J. García-Bellido, D. W. Gerdes, et al. (34 additional authors not shown)

Comments: Submitted to MNRAS. 17 pages, 6 figures

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

We present DES16C3cje, a low-luminosity, long-lived type II supernova (SN II) at redshift 0.0618, detected by the Dark Energy Survey (DES). DES16C3cje is a unique SN. The spectra are characterized by extremely narrow photospheric lines corresponding to very low expansion velocities of $\lesssim1500$ km s$^{-1}$, and the light curve shows an initial peak that fades after 50 days before slowly rebrightening over a further 100 days to reach an absolute brightness of M$_r\sim -15.5$ mag. The decline rate of the late-time light curve is then slower than that expected from the powering by radioactive decay of $^{56}$Co but is comparable to that expected from accretion power. Comparing the bolometric light curve with hydrodynamical models, we find that DES16C3cje can be explained by either i) a low explosion energy (0.11 foe) and relatively large $^{56}$Ni production of 0.075 M$_{\odot}$ from a $\sim15$ M$_{\odot}$ red supergiant progenitor typical of other SNe II, or ii) a relatively compact $\sim40$ M$_{\odot}$ star, explosion energy of 1 foe, and 0.08 M$_{\odot}$ of $^{56}$Ni. Both scenarios require additional energy input to explain the late-time light curve, which is consistent with fallback accretion at a rate of $\sim0.5\times{10^{-8}}$ M$_{\odot}$ s$^{-1}$.

[41]  arXiv:2001.11642 (cross-list from gr-qc) [pdf, other]

Title: Quantum Black Hole Seismology I: Echoes, Ergospheres, and Spectra

Authors: Naritaka Oshita, Daichi Tsuna, Niayesh Afshordi

Comments: 21 pages, 18 figures

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

Searches for gravitational wave echoes in the aftermath of mergers and/or formation of astrophysical black holes have recently opened a novel and surprising window into the quantum nature of their horizons. Similar to Astro- and Helioseismology, study of the spectrum of quantum black holes provides a promising method to understand their inner structure, what we call $\textit{quantum black hole seismology}$. We provide a detailed numerical and analytic description of this spectrum in terms of the properties of the Kerr spacetime and quantum black hole horizons, showing that it drastically differs from their classical counterparts. Our most significant findings are: (1) If the temperature of quantum black hole is $\lesssim 2 \times$ Hawking temperature, then it will not suffer from ergoregion instability (although the bound is looser at smaller spins), (2) We find how quantum black hole spectra pinpoint the microscopic properties of quantum structure. For example, the detailed spacing of spectral lines can distinguish whether quantum effects appear through compactness (i.e. exotic compact objects) or frequency (i.e. modified dispersion relation), (3) We find out that the overtone quasinormal modes may strongly enhance the amplitude of echo in low-frequency region, and (4) We show the invariance of the spectrum under generalized Darboux transformation of linear perturbations, showing that it is a genuine covariant observable.

[42]  arXiv:2001.11651 (cross-list from eess.IV) [pdf, other]

Title: CosmoVAE: Variational Autoencoder for CMB Image Inpainting

Authors: Kai Yi, Yi Guo, Yanan Fan, Jan Hamann, Yu Guang Wang

Comments: 7 pages, 6 figures

Subjects: Image and Video Processing (eess.IV); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Machine Learning (cs.LG); Machine Learning (stat.ML)

Cosmic microwave background radiation (CMB) is critical to the understanding of the early universe and precise estimation of cosmological constants. Due to the contamination of thermal dust noise in the galaxy, the CMB map that is an image on the two-dimensional sphere has missing observations, mainly concentrated on the equatorial region. The noise of the CMB map has a significant impact on the estimation precision for cosmological parameters. Inpainting the CMB map can effectively reduce the uncertainty of parametric estimation. In this paper, we propose a deep learning-based variational autoencoder --- CosmoVAE, to restoring the missing observations of the CMB map. The input and output of CosmoVAE are square images. To generate training, validation, and test data sets, we segment the full-sky CMB map into many small images by Cartesian projection. CosmoVAE assigns physical quantities to the parameters of the VAE network by using the angular power spectrum of the Gaussian random field as latent variables. CosmoVAE adopts a new loss function to improve the learning performance of the model, which consists of $\ell_1$ reconstruction loss, Kullback-Leibler divergence between the posterior distribution of encoder network and the prior distribution of latent variables, perceptual loss, and total-variation regularizer. The proposed model achieves state of the art performance for Planck \texttt{Commander} 2018 CMB map inpainting.

[43]  arXiv:2001.11799 (cross-list from hep-th) [pdf, other]

Title: Planckian hypersurfaces, inflation and bounces

Authors: Massimo Giovannini

Comments: 11 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)

When the different wavelengths of the scalar and tensor modes of the geometry are all assigned on the same space-like hypersurface the maximally amplified frequencies of the spectrum remain smaller than the Planck mass only if the duration of a stage of accelerated expansion and the corresponding tensor to scalar ratio are severely constrained. All the different wavelengths can be initialized on the same space-like hypersurface at the onset of inflation but this strategy and the related conclusions are plausible only for classical inhomogeneities. We argue that a whole class of potential constraints is easily evaded provided the different wavelengths of the quantum fields are assigned as soon as they cross the corresponding Planckian hypersurfaces. In this case the Cauchy data for the mode functions depend on the wavenumber so that larger wavelengths start evolving earlier while shorter wavelengths are assigned later. Within this strategy the duration of a conventional inflationary phase and the corresponding tensor to scalar ratio are not constrained but the large-scale power spectra inherit specific large-scale corrections that remain however unobservable.

[44]  arXiv:2001.11893 (cross-list from math-ph) [pdf, ps, other]

Title: Expression of the Holtsmark function in terms of hypergeometric $_2F_2$ and Airy $\mathrm{Bi}$ functions

Authors: Jean-Christophe Pain

Subjects: Mathematical Physics (math-ph); Astrophysics of Galaxies (astro-ph.GA); Atomic Physics (physics.atom-ph)

The Holtsmark distribution has applications in plasma physics, for the electric-microfield distribution involved in spectral line shapes for instance, as well as in astrophysics for the distribution of gravitating bodies. It is one of the few examples of a stable distribution for which a closed-form expression of the probability density function is known. However, the latter is not expressible in terms of elementary functions. In the present work, we mention that the Holtsmark probability density function can be expressed in terms of hypergeometric function $_2F_2$ and of Airy function of the second kind $\mathrm{Bi}$ and its derivative. The new formula is simpler than the one proposed by Lee involving $_2F_3$ and $_3F_4$ hypergeometric functions.

[45]  arXiv:2001.11915 (cross-list from physics.atom-ph) [pdf, other]

Title: Plasma-environment effects on K lines of astrophysical interest III. IPs, K thresholds, radiative rates, and Auger widths in Fe ix - Fe xvi

Authors: J. Deprince, M. A. Bautista, S. Fritzsche, J. A. Garcia, T. R. Kallman, C. Mendoza, P. Palmeri, P. Quinet

Comments: 6 pages, 5 figures, to be published in A&A

Subjects: Atomic Physics (physics.atom-ph); High Energy Astrophysical Phenomena (astro-ph.HE)

Aims. In the context of black-hole accretion disks, we aim to compute the plasma-environment effects on the atomic parameters used to model the decay of K-vacancy states in moderately charged iron ions, namely Fe ix - Fe xvi. Methods. We used the fully relativistic multiconfiguration Dirac-Fock (MCDF) method approximating the plasma electron-nucleus and electron-electron screenings with a time-averaged Debye-Huckel potential. Results. We report modified ionization potentials, K-threshold energies, wavelengths, radiative emission rates, and Auger widths for plasmas characterized by electron temperatures and densities in the ranges $10^5$ - $10^7$ K and $10^{18}$ - $10^{22}$ cm$^{-3}$. Conclusions. This study confirms that the high-resolution X-ray spectrometers onboard the future XRISM and ATHENA space missions will be capable of detecting the lowering of the K edges of these ions due to the extreme plasma conditions occurring in accretion disks around compact objects.

[46]  arXiv:2001.11964 (cross-list from gr-qc) [pdf, ps, other]

Title: Cosmographic analysis of redshift drift

Authors: Francisco S. N. Lobo (Universidade de Lisboa), Jose Pedro Mimoso (Universidade de Lisboa), Matt Visser (Victoria University of Wellington)

Comments: 24 pages

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

Redshift drift is the phenomenon whereby the observed redshift between an emitter and observer comoving with the Hubble flow in an expanding FLRW universe will slowly evolve --- on a timescale comparable to the Hubble time. There are nevertheless serious astrometric proposals for actually observing this effect. We shall however pursue a more abstract theoretical goal, and perform a general cosmographic analysis of this effect, eschewing (for now) dynamical considerations in favour of purely kinematic symmetry considerations based on FLRW spacetimes. We shall develop various exact results and series expansions for the redshift drift in terms of the present day Hubble, deceleration, jerk, snap, crackle, and pop parameters, as well as the present day redshift of the source. In particular, potential observation of this redshift drift effect is intimately related to the universe exhibiting a nonzero deceleration parameter.

Replacements for Mon, 3 Feb 20

[47]  arXiv:1803.10741 (replaced) [pdf, other]

Title: First Constraint on the Neutrino-Induced Phase Shift in the BAO Spectrum

Authors: Daniel Baumann, Florian Beutler, Raphael Flauger, Daniel Green, Anže Slosar, Mariana Vargas-Magaña, Benjamin Wallisch, Christophe Yèche

Comments: 22 pages, 8 figures, 1 table; v2: extended version of published Nat. Phys. article

Journal-ref: Nat. Phys. 15, 465 (2019)

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

[48]  arXiv:1906.00927 (replaced) [pdf, other]

Title: Redshift Evolution of the Fundamental Plane Relation in the IllustrisTNG Simulation

Authors: Shengdong Lu, Dandan Xu, Yunchong Wang, Shude Mao, Junqiang Ge, Volker Springel, Yuan Wang, Mark Vogelsberger, Naiman Jill, Lars Hernquist

Comments: 10 pages, 7 figures, 1 table. Accepted for publication in MNRAS

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

[49]  arXiv:1906.07143 (replaced) [pdf, other]

Title: Cosmology Inference from Biased Tracers using the EFT-based Likelihood

Authors: Franz Elsner, Fabian Schmidt, Jens Jasche, Guilhem Lavaux, Nhat-Minh Nguyen

Comments: 23 pages, 5 figures; v2: some numerical results updated and clarifications added, matches published version

Journal-ref: JCAP 01,029 (2020)

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

[50]  arXiv:1907.02074 (replaced) [pdf, other]

Title: On the patterns observed in Kepler multi-planet systems

Authors: Wei Zhu (CITA)

Comments: 13 pages, 10 figures. Last revised on November 6th of 2019. Figure 3 illustrates the main point of this work

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

[51]  arXiv:1908.05019 (replaced) [pdf, other]

Title: Numerical convergence of hydrodynamical simulations of galaxy formation: the abundance and internal structure of galaxies and their cold dark matter haloes

Authors: Aaron D. Ludlow (ICRAR/UWA), Joop Schaye, Matthieu Schaller (Leiden), Richard Bower (ICC/Durham)

Comments: 28 pages, 15 figures; Accepted 2020 January 29

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

[52]  arXiv:1908.09010 (replaced) [pdf]

Title: Micro-X Sounding Rocket: Transitioning from First Flight to a Dark Matter Configuration

Authors: J.S. Adams, A.J. Anderson, R. Baker, S.R. Bandler, N. Bastidon, D. Castro, M.E. Danowski, W.B. Doriese, M.E. Eckart, E. Figueroa-Feliciano, D.C. Goldfinger, S.N.T. Heine, G.C. Hilton, A.J.F. Hubbard, R.L. Kelley, C.A. Kilbourne, R.E. Manzagol-Harwood, D. McCammon, T. Okajima, F.S. Porter, C.D. Reintsema, P. Serlemitsos, S.J. Smith, P. Wikus

Comments: Proceedings of the 18th International Workshop on Low Temperature Detectors (LTD18)

Journal-ref: J Low Temp Phys (2020)

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Experiment (hep-ex); Instrumentation and Detectors (physics.ins-det)

[53]  arXiv:1909.09519 (replaced) [pdf, ps, other]

Title: Sudden Singularities in Brans-Dicke Cosmology and its Generalisations

Authors: John D. Barrow

Comments: 7 pages, no figures

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

[54]  arXiv:1910.04068 (replaced) [pdf, ps, other]

Title: Schwarzschild black hole as accelerator of accelerated particles

Authors: O. B. Zaslavskii

Comments: 9 pages. Presentation expanded. To appear in JETP Letters

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

[55]  arXiv:1910.04124 (replaced) [pdf, other]

Title: The SUrvey for Pulsars and Extragalactic Radio Bursts IV: Discovery and polarimetry of a 12.1-second radio pulsar

Authors: V. Morello, E.F. Keane, T. Enoto, S. Guillot, W.C.G. Ho, A. Jameson, M. Kramer, B.W. Stappers, M. Bailes, E.D. Barr, S. Bhandari, M. Caleb, C.M.L. Flynn, F. Jankowski, S. Johnston, W. van Straten, Z. Arzoumanian, S. Bogdanov, K.C. Gendreau, C. Malacaria, P.S. Ray, R.A. Remillard

Comments: Accepted for publication in MNRAS, 13 pages, 8 figures

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

[56]  arXiv:1910.11167 (replaced) [pdf, other]

Title: Spiral structure generated by major planets in proto-planetary disks: the role of periodic orbits near resonance

Authors: R.H. Sanders

Comments: 12 pages, 10 figures, detailed comparison with observed system added

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

[57]  arXiv:1911.00556 (replaced) [pdf, other]

Title: Viability of bouncing cosmology in energy-momentum-squared gravity

Authors: Ahmed H. Barbar, Adel M. Awad, Mohammad T. AlFiky

Comments: 28 pages, 4 figures, v2: minor title change, typos corrected, some discussions added and others improved, references added, accepted in Phys. Rev. D

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

[58]  arXiv:1911.00634 (replaced) [pdf, other]

Title: Statistics of VHE gamma-Rays in Temporal Association with Radio Giant Pulses from the Crab Pulsar

Authors: MAGIC Collaboration: M. L. Ahnen (1), S. Ansoldi (2,3), L. A. Antonelli (4), C. Arcaro (5), A. Babić (6), B. Banerjee (7), P. Bangale (8), U. Barres de Almeida (8,9), J. A. Barrio (10), J. Becerra González (11), W. Bednarek (12), E. Bernardini (13,14), A. Berti (2,15), W. Bhattacharyya (13), B. Biasuzzi (2), A. Biland (1), O. Blanch (16), G. Bonnoli (17), R. Carosi (17), A. Carosi (4), A. Chatterjee (7), S. M. Colak (16), P. Colin (8), E. Colombo (11), J. L. Contreras (10), J. Cortina (16), S. Covino (4), P. Cumani (16), P. Da Vela (17), F. Dazzi (4), A. De Angelis (5), B. De Lotto (2), F. Di Pierro (5), M. Doert (18), A. Domínguez (10), D. Dominis Prester (6), D. Dorner (19), M. Doro (5), S. Einecke (18), D. Eisenacher Glawion (19), D. Elsaesser (18), M. Engelkemeier (18), et al. (105 additional authors not shown)

Comments: 15 pages, 7 figures, accepted for publication by Astronomy and Astrophysics

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

[59]  arXiv:1911.01016 (replaced) [pdf, other]

Title: Two-year Cosmology Large Angular Scale Surveyor (CLASS) Observations: A First Detection of Atmospheric Circular Polarization at Q Band

Authors: Matthew A. Petroff, Joseph R. Eimer, Kathleen Harrington, Aamir Ali, John W. Appel, Charles L. Bennett, Michael K. Brewer, Ricardo Bustos, Manwei Chan, David T. Chuss, Joseph Cleary, Jullianna Denes Couto, Sumit Dahal, Rolando Dünner, Thomas Essinger-Hileman, Pedro Fluxá Rojas, Dominik Gothe, Jeffrey Iuliano, Tobias A. Marriage, Nathan J. Miller, Carolina Núñez, Ivan L. Padilla, Lucas Parker, Rodrigo Reeves, Karwan Rostem, Deniz Augusto Nunes Valle, Duncan J. Watts, Janet L. Weiland, Edward J. Wollack, Zhilei Xu

Comments: 13 pages, 7 figures, published in ApJ

Journal-ref: The Astrophysical Journal 889:120 (2020)

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

[60]  arXiv:1911.06301 (replaced) [pdf, other]

Title: Neutrino Oscillation in Dense Matter

Authors: Shu Luo

Comments: 34 pages, 13 figures; more discussions and references added, some figures updated, typos and inconsistencies fixed, while results and conclusions unchanged; accepted for publication in Phy. Rev. D

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

[61]  arXiv:1912.05701 (replaced) [pdf, other]

Title: Constraining Black Hole Populations in Globular Clusters using Microlensing: Application to Omega Centauri

Authors: John Zaris, Doğa Veske, Johan Samsing, Zsuzsa Márka, Imre Bartos, Szabolcs Márka

Comments: 6 pages, 2 figures

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

[62]  arXiv:1912.11285 (replaced) [pdf, other]

Title: The origin and effect of hemispheric helicity imbalance in solar dynamo

Authors: S. Yang, V.V. Pipin, D.D. Sokoloff, K.M. Kuzanyan, H. Zhang

Comments: 15 pages 5 Figures, submitted to JPP

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

[63]  arXiv:2001.01209 (replaced) [pdf, other]

Title: Dark Matter in CCDs at Modane (DAMIC-M): a silicon detector apparatus searching for low-energy physics processes

Authors: Steven Juhyung Lee, Ben Kilminster, Anna Macchiolo

Comments: Proceeding for the IPRD19 conference

Subjects: Instrumentation and Detectors (physics.ins-det); Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex)

[64]  arXiv:2001.04494 (replaced) [pdf, other]

Title: Scalar correlation functions for a double-well potential in de Sitter space

Authors: Tommi Markkanen, Arttu Rajantie

Comments: 21 pages, 12 figures. v2: fixed typos, updated references

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

[65]  arXiv:2001.06225 (replaced) [pdf, other]

Title: Massive discs around low-mass stars

Authors: Thomas J. Haworth, James Cadman, Farzana Meru, Cassandra Hall, Emma Albertini, Duncan Forgan, Ken Rice, James E. Owen

Comments: 21 pages, submitted to MNRAS

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

[66]  arXiv:2001.08524 (replaced) [pdf, other]

Title: IceCube Search for Galactic Neutrino Sources based on Very High Energy Gamma-ray Observations

Authors: Ali Kheirandish

Comments: Presented at the TAUP 2019 conference (Toyama, September 9-13, 2019). arXiv admin note: substantial text overlap with arXiv:1908.08546

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

[67]  arXiv:2001.08753 (replaced) [pdf, other]

Title: The MASSIVE Survey -- XV. A Stellar Dynamical Mass Measurement of the Supermassive Black Hole in Massive Elliptical Galaxy NGC 1453

Authors: Christopher M. Liepold, Matthew E. Quenneville, Chung-Pei Ma, Jonelle L. Walsh, Nicholas J. McConnell, Jenny E. Greene, John P. Blakeslee

Comments: Accepted for publication in The Astrophysical Journal. 22 pages, 12 figures; References updated

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

[68]  arXiv:2001.10012 (replaced) [pdf, other]

Title: An all-sky proper motion map of the Sagittarius stream using Gaia DR2

Authors: T. Antoja, P. Ramos, C. Mateu, A. Helmi, F. Anders, C. Jordi, J. A. Carballo-Bello

Comments: Accepted for publication in A&A Letters. See additional material at this https URL, v2 with minor editing

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

[69]  arXiv:2001.10949 (replaced) [pdf, ps, other]

Title: Solar cycle variation of $ν_{\rm max}$ in helioseismic data and its implications for asteroseismology

Authors: Rachel Howe, William J. Chaplin, Sarbani Basu, Warrick H. Ball, Guy R. Davies, Yvonne Elsworth, Steven J. Hale, Andrea Miglio, Martin Bo Nielsen, Lucas S. Viani

Comments: 6 pages, 4 figures, published in MNRAS Letters, 2020, vol 493, pages L49 - 53 Corrected error in metadata list of authors

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

[70]  arXiv:2001.11048 (replaced) [pdf, other]

Title: MOVES III. Simultaneous X-ray and ultraviolet observations unveiling the variable environment of the hot Jupiter HD 189733b

Authors: V. Bourrier, P. J. Wheatley, A. Lecavelier des Etangs, G. King, T. Louden, D. Ehrenreich, R. Fares, Ch. Helling, J. Llama, M. M. Jardine, A. A. Vidotto

Comments: 22 pages, 21 figures, accepted for publication in MNRAS on 23 January 2020

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

[71]  arXiv:2001.11418 (replaced) [pdf, ps, other]

Title: The Nature of the Double Nuclei in the Barred S0 Galaxy IC676

Authors: Zhimin Zhou, Jun Ma, Xu Zhou, Hong Wu

Comments: 15 pages, 7 figures, accepted by ApJ. Comments welcome

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

• New submissions
• Cross-lists
• Replacements