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New submissions for Thu, 26 Mar 20

[1]  arXiv:2003.11029 [pdf, other]

Title: Chemical evolution of ultra-faint dwarf galaxies in the self-consistently calculated IGIMF theory

Authors: Zhiqiang Yan, Tereza Jerabkova, Pavel Kroupa

Comments: 17 pages, 16 figures, accepted for publication in A&A

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

The galaxy-wide stellar initial mass function (gwIMF) of a galaxy in dependence of its metallicity and star formation rate (SFR) can be calculated by the integrated galactic IMF (IGIMF) theory. Lacchin et al. (2019) apply the IGIMF theory for the first time to study the chemical evolution of the ultra-faint dwarf (UFD) satellite galaxies and failed to reproduce the data. Here, we find that the IGIMF theory is naturally consistent with the data. We apply the time-evolving gwIMF calculated at each timestep. The number of type Ia supernova explosions per unit stellar mass formed is renormalised according to the gwIMF. The chemical evolution of Bo\"otes I, one of the best observed UFD, is calculated. Our calculation suggests a mildly bottom-light and top-light gwIMF for Bo\"otes I, and that this UFD has the same gas-consumption timescale as other dwarfs but was quenched about 0.1 Gyr after formation, being consistent with independent estimations and similar to Dragonfly 44. The recovered best fitting input parameters in this work are not covered in the work of Lacchin et al. (2019), creating the discrepancy between our conclusions. In addition, a detailed discussion of uncertainties is presented addressing how the results of chemical evolution models depend on applied assumptions. This study demonstrates the power of the IGIMF theory in understanding the star-formation in extreme environments and shows that UDFs are a promising pathway to constrain the variation of the low-mass stellar IMF.

[2]  arXiv:2003.11030 [pdf, ps, other]

Title: The unusual behaviour of the young X-ray pulsar SXP 1062 during the 2019 outburst

Authors: Sergey S. Tsygankov, Victor Doroshenko, Alexander A. Mushtukov, Frank Haberl, Georgios Vasilopoulos, Chandreyee Maitra, Andrea Santangelo, Alexander A. Lutovinov, Juri Poutanen

Comments: 7 pages, 6 figures; accepted for publication in A&A

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

We present results of the first dedicated observation of the young X-ray pulsar SXP 1062 in the broad X-ray energy band obtained during its 2019 outburst with the NuSTAR and XMM-Newton observatories. The analysis of the pulse-phase averaged and phase-resolved spectra in the energy band from 0.5 to 70 keV did not reveal any evidence for the presence of a cyclotron line. The spin period of the pulsar was found to have decreased to 979.48+/-0.06 s implying a ~10% reduction compared to the last measured period during the monitoring campaign conducted about five years ago, and is puzzling considering that the system apparently did not show major outbursts ever since. The switch of the pulsar to the spin-up regime supports the common assumption that torques acting on the accreting neutron star are nearly balanced and thus SXP 1062 likely also spins with a period close to the equilibrium value for this system. The current monitoring of the source revealed also a sharp drop of its soft X-ray flux right after the outburst, which is in drastic contrast to the behaviour during the previous outburst when the pulsar remained observable for years with only a minor flux decrease after the end of the outburst. This unexpected off state of the source lasted for at most 20 days after which SXP 1062 returned to the level observed during previous campaigns. We discuss this and other findings in context of the modern models of accretion onto strongly magnetized neutron stars.

[3]  arXiv:2003.11033 [pdf, other]

Title: Relative Alignment between Dense Molecular Cores and Ambient Magnetic Field: The Synergy of Numerical Models and Observations

Authors: Che-Yu Chen, Erica A. Behrens, Jasmin E. Washington, Laura M. Fissel, Rachel K. Friesen, Zhi-Yun Li, Jaime E. Pineda, Adam Ginsburg, Helen Kirk, Samantha Scibelli, Felipe Alves, Elena Redaelli, Paola Caselli, Anna Punanova, James Di Francesco, Erik Rosolowsky, Stella S. R. Offner, Peter G. Martin, Ana Chacón-Tanarro, Hope H.-H. Chen, Michael C.-Y. Chen, Jared Keown, Youngmin Seo, Yancy Shirley, Hector G. Arce, Alyssa A. Goodman, Christopher D. Matzner, Philip C. Myers, Ayushi Singh

Comments: 18 pages, 11 figures, accepted for publication in MNRAS

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

The role played by magnetic field during star formation is an important topic in astrophysics. We investigate the correlation between the orientation of star-forming cores (as defined by the core major axes) and ambient magnetic field directions in 1) a 3D MHD simulation, 2) synthetic observations generated from the simulation at different viewing angles, and 3) observations of nearby molecular clouds. We find that the results on relative alignment between cores and background magnetic field in synthetic observations slightly disagree with those measured in fully 3D simulation data, which is partly because cores identified in projected 2D maps tend to coexist within filamentary structures, while 3D cores are generally more rounded. In addition, we examine the progression of magnetic field from pc- to core-scale in the simulation, which is consistent with the anisotropic core formation model that gas preferably flow along the magnetic field toward dense cores. When comparing the observed cores identified from the GBT Ammonia Survey (GAS) and Planck polarization-inferred magnetic field orientations, we find that the relative core-field alignment has a regional dependence among different clouds. More specifically, we find that dense cores in the Taurus molecular cloud tend to align perpendicular to the background magnetic field, while those in Perseus and Ophiuchus tend to have random (Perseus) or slightly parallel (Ophiuchus) orientations with respect to the field. We argue that this feature of relative core-field orientation could be used to probe the relative significance of the magnetic field within the cloud.

[4]  arXiv:2003.11035 [pdf, other]

Title: Decadal Variability Survey in MACSJ1149

Authors: John Della Costa III, Vicki L. Sarajedini, Louis-Gregory Strolger

Comments: 17 pages, 9 figures, 3 tables, accepted for publication in ApJ

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

We present a long temporal baseline variability survey in the Frontier Field MACSJ1149. In this study, we identify active galactic nuclei (AGNs) and other transient sources via their variability using over a decade of Hubble Space Telescope (HST) images for thousands of galaxies in the cluster region and detect significant variability in galaxies extending down to an apparent nuclear magnitude of m$_{i}$ $<$ 26.5. Our analysis utilizes HST images obtained in six different wavelengths from 435 nm to 1.6 microns and covers time scales 12 hours to 12 years apart. We find that $\sim$2% of galaxies in these images are variable with 49 AGN candidates and 4 new supernovae candidates detected. Half of the variables are in the cluster and these are primarily elliptical galaxies displaying variability only in the near-infrared bands. About 20% of the AGN candidates have morphologies and colors consistent with quasars, though most of the variables appear to be dominated by the host galaxy light. The structure function for these sources show a greater amplitude of variability at shorter wavelengths with slopes shallower than typical quasars. We also report a previously unknown Einstein cross identified in this field.

[5]  arXiv:2003.11036 [pdf, other]

Title: Detecting Multiple DLAs per Spectrum in SDSS DR12 with Gaussian Processes

Authors: Ming-Feng Ho, Simeon Bird, Roman Garnett

Comments: 24 pages, 22 figures, plus 3 tables of figure values

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA); Data Analysis, Statistics and Probability (physics.data-an)

We present a revised version of our automated technique using Gaussian processes (GPs) to detect Damped Lyman-$\alpha$ absorbers (DLAs) along quasar (QSO) sightlines. The main improvement is to allow our Gaussian process pipeline to detect multiple DLAs along a single sightline. Our DLA detections are regularised by an improved model for the absorption from the Lyman-$\alpha$ forest which improves performance at high redshift. We also introduce a model for unresolved sub-DLAs which reduces mis-classifications of absorbers without detectable damping wings. We compare our results to those of two different large-scale DLA catalogues and provide a catalogue of the processed results of our Gaussian process pipeline using 158 825 Lyman-$\alpha$ spectra from SDSS data release 12. We present updated estimates for the statistical properties of DLAs, including the column density distribution function (CDDF), line density ($dN/dX$), and neutral hydrogen density ($\Omega_{\textrm{DLA}}$).

[6]  arXiv:2003.11039 [pdf, other]

Title: The SkyMapper-Gaia RVS view of the Sausage -- an investigation of the metallicity and mass of the Milky Way's last major merger

Authors: Diane K Feuillet, Sofia Feltzing, Christian Sahlholdt, Luca Casagrande

Comments: 16 pages, 11 figures + 3 appendices, 4 figures, submitted to MNRAS

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

We characterize the Gaia-Sausage kinematic structure recently discovered in the Galactic halo using photometric metallicities from the SkyMapper survey, and kinematics from Gaia radial velocities measurements. By examining the metallicity distribution functions (MDFs) of stars binned in kinematic/action spaces, we find that the $\sqrt{J_R}$ vs $L_z$ space allows for the cleanest selection of Sausage stars with minimal contamination from disc or halo stars formed in situ or in other past mergers. Stars with $30 \leq \sqrt{J_R} \leq 50$ (kpc km s$^{-1})^{1/2}$ and $-500 \leq L_z \leq 500$ kpc km s$^{-1}$ have a narrow MDF centered at [Fe/H] $= -1.17$ dex with a dispersion of 0.34 dex. This [Fe/H] estimate is more metal-rich than literature estimates by $0.1-0.3$ dex. Based on the MDFs, we find that selection of Sausage stars in other kinematic/action spaces without additional population information leads to contaminated samples. The clean Sausage sample selected according to our criteria is {\it slightly} retrograde and lies along the blue sequence of the high $V_T$ halo CMD dual sequence. Using a galaxy mass-metallicity relation derived from cosmological simulations and assuming a mean stellar age of 10 Gyr we estimate the mass of the Sausage progenitor satellite to be $10^{8.85-9.85}$ M$_{\odot}$, which is consistent with literature estimates based on disc dynamic and simulations. Additional information on detailed abundances and ages would be needed for a more sophisticated selection of purely Sausage stars.

[7]  arXiv:2003.11045 [pdf]

Title: Disk-Integrated Thermal Properties of Ceres Measured at Millimeter Wavelengths

Authors: Jian-Yang Li, Arielle Moullet, Timothy N. Titus, Henry H. Hsieh, Mark V. Sykes

Comments: 21 pages, 4 figures, 3 tables

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

We observed Ceres at three epochs in 2015 November and 2017 September and October with ALMA 12-meter array and in 2017 October with the ALMA Compact Array (ACA), all at ~265 GHz continuum (wavelengths of ~1.1 mm) to map the temperatures of Ceres over a full rotation at each epoch. We also used 2017 October ACA observations to search for HCN. The disk-averaged brightness temperature of Ceres is measured to be between 170 K and 180 K during our 2017 observations. The rotational lightcurve of Ceres shows a double peaked shape with an amplitude of about 4%. Our HCN search returns a negative result with an upper limit production rate of ~2$\times$10$^{24}$ molecules s$^{-1}$, assuming globally uniform production and a Haser model. A thermophysical model suggests that Ceres's top layer has higher dielectric absorption than lunar-like materials at a wavelength of 1 mm. However, previous observations showed that the dielectric absorption of Ceres decreases towards longer wavelengths. Such distinct dielectric properties might be related to the hydrated phyllosilicate composition of Ceres and possibly abundant $\mu$m-sized grains on its surface. The thermal inertia of Ceres is constrained by our modeling as likely being between 40 and 160 tiu, much higher than previous measurements at infrared wavelengths. Modeling also suggests that Ceres's lightcurve is likely dominated by spatial variations in its physical or compositional properties that cause changes in Ceres's observed thermal properties and dielectric absorption as it rotates.

[8]  arXiv:2003.11074 [pdf, other]

Title: The Milky Way's bar structural properties from gravitational waves

Authors: Martijn J. C. Wilhelm, Valeriya Korol, Elena M. Rossi, Elena D'Onghia

Comments: Submitted to MNRAS, 12 pages, 9 figures, 1 table

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

The Laser Interferometer Space Antenna (LISA) will enable Galactic gravitational wave (GW) astronomy by individually resolving $ > 10^4$ signals from double white dwarf (DWD) binaries throughout the Milky Way. In this work we assess for the first time the potential of LISA data to map the Galactic stellar bar and spiral arms, since GWs are unaffected by stellar crowding and dust extinction unlike optical observations of the bulge region. To achieve this goal we combine a realistic population of Galactic DWDs with a high-resolution N-Body simulation a galaxy in good agreement with the Milky Way. We then model GW signals from our synthetic DWD population and reconstruct the structure of the simulated Galaxy from mock LISA observations. Our results show that while the low signal contrast between the background disc and the spiral arms hampers our ability to characterise the spiral structure, the stellar bar will instead clearly appear in the GW map of the bulge. The bar length and bar width derived from these synthetic observations are underestimated, respectively within $1\sigma$ and at a level greater than $2\sigma$, but the resulting axis ratio agrees to well within $1\sigma$, while the viewing angle is recovered to within one degree. These are competitive constraints compared to those from electromagnetic tracers, and they are obtained with a completely independent method. We therefore foresee that the synergistic use of GWs and electromagnetic tracers will be a powerful strategy to map the bar and the bulge of the Milky Way.

[9]  arXiv:2003.11084 [pdf, other]

Title: Exocomets: A spectroscopic survey

Authors: I. Rebollido, C. Eiroa, B. Montesinos, J. Maldonado, E. Villaver, O. Absil, A. Bayo, H. Canovas, A. Carmona, Ch. Chen, S. Ertel, Th. Henning, D. P. Iglesias, R. Launhardt, R. Liseau, G. Meeus, A. Moór, A. Mora, J. Olofsson, G. Rauw, P. Riviere-Marichalar

Comments: Accepted in A&A on March 23rd 2020

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

While exoplanets are now routinely detected, the detection of small bodies in extrasolar systems remains challenging. Since the discovery of sporadic events interpreted as exocomets (Falling Evaporating Bodies) around $\beta$ Pic in the early 80s, only $\sim$20 stars have been reported to host exocomet-like events. We aim to expand the sample of known exocomet-host stars, as well as to monitor the hot-gas environment around stars with previously known exocometary activity. We have obtained high-resolution optical spectra of a heterogeneous sample of 117 main-sequence stars in the spectral type range from B8 to G8. The data have been collected in 14 observing campaigns expanding over 2 years from both hemispheres. We have analysed the Ca ii K&H and Na i D lines in order to search for non-photospheric absorptions originated in the circumstellar environment, and for variable events that could be caused by outgassing of exocomet-like bodies. We have detected non-photospheric absorptions towards 50% of the sample, attributing a circumstellar origin to half of the detections (i.e. 26% of the sample). Hot circumstellar gas is detected in the metallic lines inspected via narrow stable absorptions, and/or variable blue-/red-shifted absorption events. Such variable events were found in 18 stars in the Ca ii and/or Na i lines; 6 of them are reported in the context of this work for the first time. In some cases the variations we report in the Ca ii K line are similar to those observed in $\beta$ Pic. While we do not find a significant trend with the age or location of the stars, we do find that the probability of finding CS gas in stars with larger vsin i is higher. We also find a weak trend with the presence of near-infrared excess, and with anomalous ($\lambda$ Boo-like) abundances, but this would require confirmation by expanding the sample.

[10]  arXiv:2003.11085 [pdf, other]

Title: Detailed abundances in the Galactic center: Evidence of a metal-rich alpha-enhanced stellar population

Authors: B. Thorsbro, N. Ryde, R. M. Rich, M. Schultheis, F. Renaud, E. Spitoni, T. K. Fritz, A. Mastrobuono-Battisti, L. Origlia, F. Matteucci, R. Schödel

Comments: 13 pages, 10 figures, accepted for publication in ApJ

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

We present a detailed study of the composition of 20 M giants in the Galactic center with 15 of them confirmed to be in the Nuclear Star Cluster. As a control sample we have also observed 7 M giants in the Milky Way Disk with similar stellar parameters. All 27 stars are observed using the NIRSPEC spectograph on the KECK II telescope in the K-band at a resolving power of R=23,000. We report the first silicon abundance trends versus [Fe/H] for stars in the Galactic center. While finding a disk/bulge like trend at subsolar metallicities, we find that [Si/Fe] is enhanced at supersolar metallicities. We speculate on possible enrichment scenarios to explain such a trend. However, the sample size is modest and the result needs to be confirmed by additional measurements of silicon and other \textalpha-elements. We also derive a new distribution of [Fe/H] and find the most metal rich stars at [Fe/H]=+0.5 dex, confirming our earlier conclusions that the Galactic center hosts no stars with extreme chemical composition.

[11]  arXiv:2003.11096 [pdf, other]

Title: Dark matter haloes in the multicomponent model. III. From dwarfs to galaxy clusters

Authors: Keita Todoroki, Mikhail V. Medvedev

Comments: 17 pages, 11 figures

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

A possibility of DM being multicomponent has a strong implication on resolving decades-long known cosmological problems on small scale. In addition to elastic scattering, the model allows for inelastic interactions, which can be characterized by a 'velocity kick' parameter. The simplest 2cDM model with cross section $0.01\lesssim\sigma/m<1\textrm{ cm}^{2}{ \rm g}^{-1}$ and the kick velocity $V_{k}\simeq 100\textrm{ km s}^{-1}$ has been shown to robustly resolve the missing satellites, core-cusp, and too-big-to-fail problems in $N$-body cosmological simulations tested on MW-like haloes of a virial mass $\sim5 \times 10^{11}$ M$_{\odot}$ (Paper I $\&$ II). With the aim of further constraining the parameter space available for the 2cDM model, we extend our analysis to dwarf and galaxy cluster haloes with their virial mass of $\sim 10^7 - 10^8$ and $\sim 10^{13} - 10^{14}$ M$_{\odot}$, respectively. We find $\sigma_{0} / m \gtrsim 0.1 \textrm{ cm}^{2}{\rm g}^{-1}$ is preferentially disfavored for both dwarfs and galaxy cluster haloes in comparison with observations, while $\sigma_{0} / m = 0.001 \textrm{ cm}^{2}{\rm g}^{-1}$ causes little perceptible difference from that of the CDM counterpart for most of the cross section's velocity dependence studied in this work. Our main result is that within the reasonable set of parameters the 2cDM model can successfully explain the observational trends seen in dwarf galaxy and galaxy cluster haloes and the model leaves us an open window for other possible alternative DM models.

[12]  arXiv:2003.11098 [pdf, other]

Title: An information theoretic framework for classifying exoplanetary system architectures

Authors: Gregory J. Gilbert, Daniel C. Fabrycky

Comments: 18 pages, submitted to AJ. Comments welcome

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

We propose several descriptive measures to characterize the arrangements of planetary masses, periods, and mutual inclinations within exoplanetary systems. These measures are based in complexity theory and capture the global, system-level trends of each architecture. Our approach considers all planets in a system simultaneously, facilitating both intra-system and inter-system analysis. We find that based on these measures, Kepler's high-multiplicity ($N\geq3$) systems can be explained if most systems belong to a single intrinsic population, with a subset of high-multiplicity systems ($\sim20\%$) hosting additional, undetected planets intermediate in period between the known planets. We confirm prior findings that planets within a system tend to be roughly the same size and approximately coplanar. We find that forward modeling has not yet reproduced the high degree of spacing similarity (in log-period) actually seen in the Kepler data. Although our classification scheme was developed using compact Kepler multis as a test sample, our methods can be immediately applied to any other population of exoplanetary systems. We apply this classification scheme to (1) quantify the similarity between systems, (2) resolve observational biases from physical trends, and (3) identify which systems to search for additional planets and where to look for these planets.

[13]  arXiv:2003.11101 [pdf, other]

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

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

Comments: Accepted for publication by ApJ, 14 pages, 10 figures

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

Standing shocks are believed to be responsible for stationary Type II solar radio bursts, whereas drifting Type II bursts are excited by moving shocks often related to coronal mass ejections (CMEs). Observations of either stationary or drifting Type II bursts are common, but a transition between the two states has not yet been reported. Here, we present a Type II burst which shows a clear, continuous transition from a stationary to a drifting state, the first observation of its kind. Moreover, band splitting is observed in the stationary parts of the burst, as well as intriguing negative and positive frequency-drift fine structures within the stationary emissions. The relation of the radio emissions to an observed jet and a narrow CME were investigated across multiple wavelengths, and the mechanisms leading to the transitioning Type II burst were determined. We find that a jet eruption generates a streamer-puff CME and that the interplay between the CME-driven shock and the streamer is likely to be responsible for the observed radio emissions.

[14]  arXiv:2003.11104 [pdf, other]

Title: Thermally Unstable Cooling Stimulated by Uplift: The Spoiler Clusters

Authors: C. G. Martz, B. R. McNamara, P. E. J. Nulsen, A. N. Vantyghem, M-J. Gingras, Iu. V. Babyk, H. R. Russell, A. C. Edge, M. McDonald, P. D. Tamhane, A. C. Fabian, M. T. Hogan

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

We analyzed Chandra X-ray observations of five galaxy clusters whose atmospheric cooling times, entropy parameters, and cooling time to free-fall time ratios within the central galaxies lie below 1 Gyr, below 30 keV cm^2, and between 20 < tcool/tff < 50, respectively. These thermodynamic properties are commonly associated with molecular clouds, bright H-alpha emission, and star formation in central galaxies. However, none of these clusters have detectable H-alpha indicated in the ACCEPT database, nor do they have significant star formation rates or detectable molecular gas. Among these, only RBS0533 has a detectable radio/X-ray bubble which are commonly observed in cooling atmospheres. Signatures of uplifted, high metallicity atmospheric gas are absent. Despite its prominent X-ray bubble, RBS0533 lacks significant levels of molecular gas. Cold gas is absent at appreciable levels in these systems perhaps because their radio sources have failed to lift low entropy atmospheric gas to an altitude where the ratio of the cooling time to the free-fall time falls below unity.

[15]  arXiv:2003.11106 [pdf, other]

Title: Orbital Parameter Determination for Wide Stellar Binary Systems in the Age of \textit{Gaia}

Authors: Logan A. Pearce, Adam L. Kraus, Trent J. Dupuy, Andrew W. Mann, Elisabeth R. Newton, Benjamin N. Tofflemire, Andrew W. Vanderburg

Comments: 18 pages, 10 figures, accepted for publication in ApJ

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

The orbits of binary stars and planets, particularly eccentricities and inclinations, encode the angular momentum within these systems. Within stellar multiple systems, the magnitude and (mis)alignment of angular momentum vectors among stars, disks, and planets probes the complex dynamical processes guiding their formation and evolution. The accuracy of the \textit{Gaia} catalog can be exploited to enable comparison of binary orbits with known planet or disk inclinations without costly long-term astrometric campaigns. We show that \textit{Gaia} astrometry can place meaningful limits on orbital elements in cases with reliable astrometry, and discuss metrics for assessing the reliability of \textit{Gaia} DR2 solutions for orbit fitting. We demonstrate our method by determining orbital elements for three systems (DS Tuc AB, GK/GI Tau, and Kepler-25/KOI-1803) using \textit{Gaia} astrometry alone. We show that DS Tuc AB's orbit is nearly aligned with the orbit of DS Tuc Ab, GK/GI Tau's orbit might be misaligned with their respective protoplanetary disks, and the Kepler-25/KOI-1803 orbit is not aligned with either component's transiting planetary system. We also demonstrate cases where \textit{Gaia} astrometry alone fails to provide useful constraints on orbital elements. To enable broader application of this technique, we introduce the python tool \texttt{lofti\_gaiaDR2} to allow users to easily determine orbital element posteriors.

[16]  arXiv:2003.11109 [pdf, other]

Title: Cloud Identification from All-sky Camera Data with Machine Learning

Authors: Michael Mommert

Comments: accepted by AJ, code available at this https URL

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

Most ground-based observatories are equipped with wide-angle all-sky cameras to monitor the night sky conditions. Such camera systems can be used to provide early warning of incoming clouds that can pose a danger to the telescope equipment through precipitation, as well as for sky quality monitoring. We investigate the use of different machine learning approaches for automating the identification of mostly opaque clouds in all-sky camera data as a cloud warning system. In a deep-learning approach, we train a Residual Neural Network (ResNet) on pre-labeled camera images. Our second approach extracts relevant and localized image features from camera images and uses these data to train a gradient-boosted tree-based model (lightGBM). We train both model approaches on a set of roughly 2,000 images taken by the all-sky camera located at Lowell Observatory's Discovery Channel Telescope, in which the presence of clouds has been labeled manually. The ResNet approach reaches an accuracy of 85% in detecting clouds in a given region of an image, but requires a significant amount of computing resources. Our lightGBM approach achieves an accuracy of 95% with a training sample of ~1,000 images and rather modest computing resources. Based on different performance metrics, we recommend the latter feature-based approach for automated cloud detection. Code that was built for this work is available online.

[17]  arXiv:2003.11121 [pdf, other]

Title: Carnegie Supernova Project-II: A new method to photometrically identify sub-types of extreme Type Ia Supernovae

Authors: C. Ashall, J. Lu, C. Burns, E. Y. Hsiao, M. Stritzinger, N. B. Suntzeff, M. M. Phillips, E. Baron, C. Contreras, S. Davis, L. Galbany, P. Hoeflich, S. Holmbo, N. Morrell, E. Karamehmetoglu, K. Krisciunas, S. Kumar, M. Shahbandeh, S. Uddin

Comments: accepted for publication in ApjL

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

We present a new method to photometrically delineate between various sub-types of type Ia supernovae (SNe Ia). Using the color-stretch parameters, $s_{BV}$ or $s_{gr}$, and the time of i-band primary maximum relative to the B-band or g-band maximum it is demonstrated that 2003fg-like, 1991bg-like, and 2002cx-like SNe Ia can readily be identified. In the cases of these extreme SNe Ia, their primary i-band maximum occurs after the time of the B or g band maxima. We suggest that the timing of the i-band maximum can reveal the physical state of the SN Ia explosion as it traces: i) the speed of the recombination front of iron group elements in the ejecta, ii) the temperature evolution and rate of adiabatic cooling in the ejecta and, iii) the presence of interaction with a stellar envelope. This photometric sub-typing can be used in conjunction with other SNe analysis, such as the Branch diagram, to examine the physics and diversity of SNe Ia. The results here can also be used to screen out non-Ia SNe from cosmological samples that do not have complete spectroscopic typing. Finally, as future surveys like LSST create large databases of light curves of many objects this photometric identification can be used to readily identify and study the rates and bulk properties of peculiar SNe Ia.

[18]  arXiv:2003.11134 [pdf, ps, other]

Title: How Does Magnetic Reconnection Drive the Early Stage Evolution of Coronal Mass Ejections?

Authors: Chunming Zhu, Jiong Qiu, Paulett Liewer, Angelos Vourlidas, Michael Spiegel, Qiang Hu

Comments: 31 pages, 13 figures, 1 table. Accepted for publication by ApJ

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

Theoretically, CME kinematics are related to magnetic reconnection processes in the solar corona. However, the current quantitative understanding of this relationship is based on the analysis of only a handful of events. Here we report a statistical study of 60 CME-flare events from August 2010 to December 2013. We investigate kinematic properties of CMEs and magnetic reconnection in the low corona during the early phase of the eruptions, by combining limb observations from STEREO with simultaneous on-disk views from SDO. For a subset of 42 events with reconnection rate evaluated by the magnetic fluxes swept by the flare ribbons on the solar disk observed from SDO, we find a strong correlation between the peak CME acceleration and the peak reconnection rate. Also, the maximum velocities of relatively fast CMEs (> 600 km/s) are positively correlated with the reconnection flux, but no such correlation is found for slow CMEs. A time-lagged correlation analysis suggests that the distribution of the time lag of CME acceleration relative to reconnection rate exhibits three peaks, approximately 10 minutes apart, and on average, acceleration-lead events have smaller reconnection rates. We further compare the CME total mechanical energy with the estimated energy in the current sheet. The comparison suggests that, for small-flare events, reconnection in the current sheet alone is insufficient to fuel CMEs. Results from this study suggest that flare reconnection may dominate the acceleration of fast CMEs, but for events of slow CMEs and weak reconnection, other mechanisms may be more important.

[19]  arXiv:2003.11138 [pdf, other]

Title: Apparent radio transients mapping the near-Earth plasmaenvironment

Authors: Mark J. Kuiack, Ralph A.M.J. Wijers, Aleksandar Shulevski, Antonia Rowlinson

Comments: 12 pages, 13 figures. Submitted to MNRAS

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

We report the discovery of bright, fast, radio flares lasting tens of seconds with the AARTFAAC high-cadence all-sky survey at 60 MHz. The vast majority of these coincide with known, bright radio sources that brighten by factors of up to 100 during such an event. We attribute them to magnification events induced by plasma near the Earth, most likely in the densest parts of the ionosphere. They can occur both in relative isolation, during otherwise quiescent ionospheric conditions, and in large clusters during more turbulent ionospheric conditions. We also find one event that has many properties in common with these events, but has a very well-determined dispersion delay as a function of frequency consistent with a very distant Galactic or extragalactic origin. If astrophysical, it represents extreme emission with a minimum brightness temperature of $10^{28-34}$ K.

[20]  arXiv:2003.11141 [pdf, other]

Title: An Effective Field Theory Analysis of the First LUX Dark Matter Search

Authors: D.S. Akerib, S. Alsum, H.M. Araújo, X. Bai, J. Balajthy, A. Baxter, E.P. Bernard, A. Bernstein, T.P. Biesiadzinski, E.M. Boulton, B. Boxer, P. Brás, S. Burdin, D. Byram, M.C. Carmona-Benitez, C. Chan, J.E. Cutter, L. de Viveiros, E. Druszkiewicz, A. Fan, S. Fiorucci, R.J. Gaitskell, C. Ghag, M.G.D. Gilchriese, C. Gwilliam, C.R. Hall, S.J. Haselschwardt, S.A. Hertel, D.P. Hogan, M. Horn, D.Q. Huang, C.M. Ignarra, R.G. Jacobsen, O. Jahangir, W. Ji, K. Kamdin, K. Kazkaz, D. Khaitan, E.V. Korolkova, S. Kravitz, V.A. Kudryavtsev, N.A. Larsen, E. Leason, B.G. Lenardo, K.T. Lesko, J. Liao, J. Lin, A. Lindote, M.I. Lopes, A. Manalaysay, R.L. Mannino, N. Marangou, D.N. McKinsey, D.-M. Mei, M. Moongweluwan, J.A. Morad, A.St.J. Murphy, A. Naylor, C. Nehrkorn, H.N. Nelson, F. Neves, A. Nilima, et al. (35 additional authors not shown)

Comments: 11 pages, 6 figures

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

The Large Underground Xenon (LUX) dark matter search was a 250-kg active mass dual-phase time projection chamber that operated by detecting light and ionization signals from particles incident on a xenon target. In December 2015, LUX reported a minimum 90% upper C.L. of 6e-46 cm^2 on the spin-independent WIMP-nucleon elastic scattering cross section based on a 1.4e4 kg*day exposure in its first science run. Tension between experiments and the absence of a definitive positive detection suggest it would be prudent to search for WIMPs outside the standard spin-independent/spin-dependent paradigm. Recent theoretical work has identified a complete basis of 14 independent effective field theory (EFT) operators to describe WIMP-nucleon interactions. In addition to spin-independent and spin-dependent nuclear responses, these operators can produce novel responses such as angular-momentum-dependent and spin-orbit couplings. Here we report on a search for all 14 of these EFT couplings with data from LUX's first science run. Limits are placed on each coupling as a function of WIMP mass.

[21]  arXiv:2003.11175 [pdf, ps, other]

Title: Diversity of gamma-ray and Radio Variabilities of Bright Blazars and Implications for gamma-ray Emission Location

Authors: Hai-Ming Zhang (NJU), Zhen-Jie Wang (GXU), Jin Zhang (NAOC), Ting-Feng Yi (YNNU), Liang Chen (SHAO), Rui-Jing Lu (GXU), En-Wei Liang (GXU)

Comments: 34 pages, 11 figures, 2 tables, accepted for publication in PASJ

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

Violent multi-wavelength variabilities are observed in gamma-ray-selected blazars. We present an analysis of long-term light curves for eight bright blazars to explore the co-variation pattern in the gamma-ray and radio bands. We extract their gamma-ray light curves and spectra with data observed by the Fermi/LAT since 2008. We find diverse co-variation patterns between the gamma-ray and radio (at 43 GHz) fluxes in these sources. The gamma-ray and radio fluxes of 3C 454.3 and PKS 1633+382 are correlated without any time-lag, suggesting that they are from the same radiation region. Similar correlation is also observed in 3C 273 and PKS 1222+216, but the radio flux is lag behind the gamma-ray flux approximately ~160 days and ~290 days, respectively. This likely suggests that their gamma-ray emission regions are located at the upstream of their radio cores at 43 GHz. The gamma-ray and radio fluxes of the other four blazars are not correlated, implying that the gamma-ray and radio emission may be from different regions in their jets. The gamma-ray light curves of the eight blazars can be decomposed into some long timescale variability components and fast spike flares. We propose that they may be attributed to the central engine activity and the magnetic reconnection process or turbulence in the local emission region, respectively.

[22]  arXiv:2003.11182 [pdf]

Title: Exploration Strategy for the Outer Planets 2023-2032: Goals and Priorities

Authors: Jeff Moore (1), Linda Spilker (2), Morgan Cable (2), Scott Edgington (2), Amanda Hendrix (3), Mark Hofstadter (2), Terry Hurford (4), Kathleen Mandt (5), Alfred McEwen (6), Carol Paty (7), Lynnae Quick (4), Abigail Rymer (5), Kunio Sayanagi (8), Britney Schmidt (9), Thomas Spilker (10) ((1) NASA Ames Research Center, (2) Jet Propulsion Laboratory, (3) Planetary Science Institute, (4) NASA Goddard Space Flight Center, (5) Johns Hopkins APL, (6) University of Arizona, (7) University of Oregon, (8) Hampton University, (9) Georgia Institute of Technology, (10) Independent Consultant)

Comments: Whitepaper to be submitted to Planetary Decadal Survey 2020

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

Exploration of the outer solar system is central to NASA's objectives. It addresses NASA's top-level strategic goal as expressed in its 2018 Strategic Plan: to understand the Sun, Earth, solar system, and universe, including searching for habitable conditions and life elsewhere, understanding the origin and evolution of the solar system, and answering fundamental scientific questions about the processes that continue to shape our solar system. The 2018 NASA authorization act from Congress includes "the search for life's origins, evolution, distribution, and future in the universe." The outer solar system provides critical evidence for how our solar system formed and evolved, and is home to extensive liquid water oceans, potentially hosting life.
This White Paper summarizes the Outer Planets Assessment Group's (OPAG's) priorities as they relate to the Decadal Survey. Our top-priority large, directed missions are, in order, completing development and launching the Europa Clipper mission, a new start for a directed Ice Giant System mission with atmospheric probe(s), and a directed Ocean Worlds mission. Continuation of Discovery and New Frontiers programs is essential to OPAG. In addition, we note the necessity of maintaining a healthy Research and Analysis (R&A) program, which includes a strong laboratory measurements component, and a robust Earth-based observing program. International partnerships are key components of these activities. OPAG's top two technology priorities are rapid development of a next-generation radioisotope power source for an Ice Giant System mission and development of key life detection technologies in support of an Ocean Worlds mission.

[23]  arXiv:2003.11252 [pdf, other]

Title: On the origin of the multi-GeV photons from the closest burst with intermediate luminosity: GRB 190829A

Authors: N. Fraija, P. Veres, P. Beniamini, A. Galvan-Gamez, B. D. Metzger, R. Barniol Duran, R. L. Becerra

Comments: 26 pages, 7 figures, Submitted to ApJ

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

Very-high-energy (VHE) emission is usually interpreted in the synchrotron-self Compton (SSC) scenario, and expected from the low-redshift and high-luminosity gamma-ray bursts (GRBs), as GRB 180720B and GRB 190114C. Recently, VHE emission was detected by the H.E.S.S. telescopes from one of the closest burst GRB 190829A which was associated with the supernova (SN) 2019oyw. In this paper, we present a temporal and spectral analysis from optical bands to Fermi-LAT energy range over multiple observational periods beginning just after the BAT trigger time and extending for almost three months. We show that the X-ray and optical observations are consistent with synchrotron forward-shock emission evolving between the characteristic and cooling spectral breaks during the early and late afterglow in a uniform-density medium. Modeling the light curves together with its spectral energy distribution, it is shown that the outflow expands with an initial bulk Lorentz factor of $\Gamma\sim 30$, which is high for a low-luminosity GRBs and low for a high-luminosity GRBs. The values of the initial bulk Lorentz factor and the isotropic equivalent energy suggest that GRB 190829A is classified as an intermediate-luminosity burst and consequently, it becomes the first burst of this class in being detected in the VHE gamma-ray band by an imaging atmospheric Cherenkov telescope, and, in turn, the first event without being simultaneously observed by the Fermi-LAT instrument. Analyzing the intermediate-luminosity bursts with $z\lesssim 0.2$ such as GRB 130702A, we show that bursts with intermediate luminosity are potential candidates to be detected in very-high energies.

[24]  arXiv:2003.11258 [pdf, other]

Title: From rest-frame luminosity functions to observer-frame colourdistributions: tackling the next challenge in cosmological simulations

Authors: Matías Bravo (1), Claudia del P. Lagos (1,2,3), Aaron S. G. Robotham (1,2), Sabine Bellstedt (1), Danail Obreschkow (1,2) ((1) International Centre for Radio Astronomy Research (ICRAR), (2) ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), (3) Cosmic Dawn Center (DAWN))

Comments: 21 pages, 18 figures. Submitted to MNRAS

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

Galaxy spectral energy distributions (SEDs) remain among the most challenging yet informative quantities to reproduce in simulations due to the large and complex mixture of physical processes that shape the radiation output of a galaxy. With the increasing number of surveys utilising broadband colours as part of their target selection criteria, the production of realistic SEDs in simulations is necessary for assisting in survey design and interpretation of observations. The recent success in reproducing the observed luminosity functions (LF) from far-UV to far-IR, using the state-of-the-art semi-analytic model Shark and the SED generator ProSpect, represents a critical step towards better galaxy colour predictions. We show that with Shark and ProSpect we can closely reproduce the optical colour distributions observed in the panchromatic GAMA survey. The treatment of feedback, star formation, central-satellite interactions and radiation re-processing by dust are critical for this achievement. The first three processes are responsible for the colour bimodality, while dust attenuation defines the mean and scatter of the blue and red populations. While a naive comparison between observation and simulations displays the known issue of over-quenching of satellite galaxies, the introduction of empirically-motivated observational errors and classification from the same group finder used in GAMA greatly reduces this tension. The introduction of random re-assignment of $\sim15\%$ of centrals/satellites as satellites/centrals on the simulation classification closely resembles the outcome of the group finder, providing a computationally less intensive method to compare simulations with observations.

[25]  arXiv:2003.11278 [pdf, ps, other]

Title: Magnetar as Central Engine of Gamma-Ray Bursts: Quasi-Universal Jet, Event Rate and X-ray Luminosity Function of Dipole Radiations

Authors: Wen-Jin Xie, Le Zou, Hong-Bang Liu, Shan-Qin Wang, En-Wei Liang (GXU)

Comments: 22 pages, 10 figures, and 1 table. Accepted for publication in ApJ

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

Early shallow-decaying X-ray afterglows of gamma-ray bursts (GRBs) may be attributed to the dipole radiations of newly-born magnetars. Assuming that the GRB jets powered by magnetars are quasi-universal, we find that the jet structure can be parameterized as a uniform jet with a luminosity of $\log L_{\rm j}/{\rm erg\ s^{-1}}=52.68^{+0.76}_{-0.33}$ (1$\sigma$) and an opening angle $\theta_{\rm j}=2.10_{-1.28}^{+1.90}$ (50\% confidence level), surrounding by a power-law decay component with an index of ${-4.00^{+0.27}_{-0.37}}$ (1$\sigma$). The inferred local GRB rate is $\rho=9.6$ Gpc$^{-3}$ yr$^{-1}$ by including both the typical GRBs and LL-GRBs as the same population. The typical viewing angle is $3.3^{o}$, and may be $20^{o}\sim30^{o}$ for LL-GRBs. The X-ray luminosity function of the dipole radiation wind can be empirically described by a broken power-law function with indices $\beta_1=0.78^{+0.16}_{-0.15}$ and $\beta_2>1.6$ broken at $\log L_{b, w}/{\rm erg\ s^{-1}}=48.51^{+0.53}_{-0.65}$. In case of that the wind outflow is collimated and co-axial with the GRB jet, we find that the wind structure is similar to the GRB jet, i.e., $\log L_{\rm c, w}/{\rm erg\ s^{-1}}=48.38^{+0.30}_{-0.48}$, $\theta_{\rm c, w}={2.65^{o}}_{-1.19^{o}}^{+0.1.73^{o}}$, and $k_{\rm w}=4.57^{+1.21}_{-0.75}$. The observed correlation between the prompt gamma-ray luminosity and X-ray luminosity of the wind may be resulted from the viewing angle effect in such a jet-wind system. Discussion on survey with the X-ray instruments on board the {\em Einstein\ Probe} mission in the soft X-ray band for the jet and wind emission is also presented.

[26]  arXiv:2003.11280 [pdf, ps, other]

Title: The gamma-ray and Optical Variability Analysis of the BL Lac Object 3FGL J0449.4-4350

Authors: Xing Yang, Tingfeng Yi, Yan Zhang, Huaizhen Li, Lisheng Mao, Haiming Zhang, Li Ma

Comments: 19 pages, 6 figures, 2 tables, Accepted for publication in PASP

Journal-ref: PASP,132:044101(2020)

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

We have assembled the historical light curves of the BL Lac Object 3FGL J0449.4-4350 at optical and gamma-ray bands, the time spanning about 10 years, analyzed the periodic variability of the light curves by using four different methods (Lomb-Scargle periodogram, REDFIT38, Jurkevich and DACF). We detected a marginally possible quasi-periodic oscillation (QPO) of ~450 days. Assuming it originates from the helical motion jet in a supermassive binary black hole (SMBBH) system undergoing major merger, we estimate the primary black hole mass M~7.7*10^{9} M_sun. To explore the origin of the gamma-ray, we investigated the optical-gamma-ray correlations using discrete correlation function (DCF) method, and found that the correlation between the two bands is very significant. This strong correlation tends to imply lepton self-synchro-Compton (LSSC) model to produce the gamma-ray.

[27]  arXiv:2003.11295 [pdf, ps, other]

Title: Reply to "Rapid $^{14}$C excursion at 3372-3371 BCE not observed at two different locations"

Authors: F. Y. Wang, H. Yu, Y. C. Zou, Z. G. Dai, K. S. Cheng

Comments: 11 pages, 1 figure, 1 table

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Geophysics (physics.geo-ph)

The nuclide $^{14}$C can be produced in the atmosphere by high energy particles and $\gamma$-rays from high-energy phenomena. Through the carbon cycle, some of $^{14}$CO$_2$ produced in the atmosphere can be retained in annual tree rings. Four events of rapid increase of the $^{14}$C content occurred in AD 775, AD 994, BC 660 and BC 3371 were found. Recently, the data of Jull et al. (2020) was inconsistent with our records around BC 3371. We measured our sample again and found the $^{14}$C records are consistent with the value in Wang et al. (2017). Therefore, our $^{14}$C records are robust. The inconsistency may be caused by the difference of calendar ages for the wood samples, or the physical origin of the event. First, crossdating on ring width can be performed only between trees whose growth has the same environmental conditions. Because the master tree-ring for dendrochronology is lack for Chinese trees. The master tree-ring from California has to be used. Therefore, the calendar ages derived from dendrochronology may be not precise. Second, the $^{14}$C even may be not global. One evidence is the variation of $^{14}$C content around AD 1006. The $^{14}$C contents of Californian trees increase 12\textperthousand~ in two years, while Japanese trees show no $^{14}$C increase.

[28]  arXiv:2003.11301 [pdf]

Title: Probabilities of collisions of planetesimals from different regions of the feeding zone of the terrestrial planets with the forming planets and the Moon

Authors: S. I. Ipatov

Comments: 30 pages

Journal-ref: Solar System Research, 2019, v. 53, N 5, p. 332-361

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

Migration of planetesimals from the feeding zone of the terrestrial planets, which was divided into seven regions depending on the distance to the Sun, was simulated. The influence of gravity of all planets was taken into account. In some cases, the embryos of the terrestrial planets rather than the planets themselves were considered; their masses were assumed to be 0.1 or 0.3 of the current masses of the planets. The arrays of orbital elements of migrated planetesimals were used to calculate the probabilities of their collisions with the planets, the Moon, or their embryos. Based on our calculations, we drew conclusions on the process of accumulation of the terrestrial planets. The embryos of the terrestrial planets, the masses of which did not exceed a tenth of the current planetary masses, accumulated planetesimals mainly from the vicinity of their orbits. When planetesimals fell onto the embryos of the terrestrial planets from the feeding zone of Jupiter and Saturn, these embryos had not yet acquired the current masses of the planets, and the material of this zone (including water and volatiles) could be accumulated in the inner layers of the terrestrial planets. The inner layers of each of the terrestrial planets were mainly formed from the material located in the vicinity of the orbit of a certain planet. The outer layers of the Earth and Venus could accumulate the same material for these two planets from different parts of the feeding zone of the terrestrial planets. The Earth and Venus could acquire more than half of their masses in 5 Myr. A relatively rapid growth of the bulk of the Martian mass can be explained by the formation of Mars' embryo (the mass of which is several times less than that of Mars) due to contraction of a rarefied condensation.

[29]  arXiv:2003.11302 [pdf, other]

Title: Physical properties of bright Ca II K fibrils in the solar chromosphere

Authors: Sepideh Kianfar, Jorrit Leenaarts, Sanja Danilovic, Jaime de la Cruz Rodríguez, Carlos José Díaz Baso

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

Broad-band images of the solar chromosphere in the Ca II H&K line cores around active regions are covered with fine bright elongated structures called bright fibrils. The mechanisms that form these structures and cause them to appear bright are still unknown. We aim to investigate the physical properties, such as temperature, line-of-sight velocity, and microturbulence, in the atmosphere that produces bright fibrils and to compare those to the properties of their surrounding atmosphere. We used simultaneous observations of a plage region in Fe I 6301-2 \r{A}, Ca II 8542 \r{A}, Ca II K, and H$\alpha$ acquired by the CRISP and CHROMIS instruments on the Swedish 1-m Solar Telescope. We manually selected a sample of 282 Ca II K bright fibrils. We compared the appearance of the fibrils in our sample to the Ca II 8542 \r{A} and H$\alpha$ data. We performed non-local thermodynamic equilibrium (non-LTE) inversions using the inversion code STiC on the Fe I 6301-2 \r{A}, Ca II 8542 \r{A}, Ca II K lines to infer the physical properties of the atmosphere. The line profiles in bright fibrils have a higher intensity in their K$_2$ peaks compared to profiles formed in the surrounding atmosphere. The inversion results show that the atmosphere in fibrils is on average $100-200$~K hotter at an optical depth log$(\tau) = -4.3$ compared to their surroundings. The line-of-sight velocity at chromospheric heights in the fibrils does not show any preference towards upflows or downflows. The microturbulence in the fibrils is on average 0.5 km s$^{-1}$ higher compared to their surroundings. Our results suggest that the fibrils have a limited extent in height, and they should be viewed as hot threads pervading the chromosphere.

[30]  arXiv:2003.11308 [pdf, other]

Title: Parallax in microlensing toward the Magellanic Clouds: impact on detection efficiency and detectability

Authors: T Blaineau (IJCLab), M. Moniez (IJCLab)

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

Aims. We study the impact of the parallax on the search for very long timescale microlensing events towards the Magellanic Clouds due to dark massive compact objects within the past MACHO and EROS, the ongoing MOA and OGLE, and the future LSST surveys. We quantify the impact of neglecting this effect on the classical event selection process and also quantify the parallax detectability without the help of follow-up observations. Methods. We define a distance between true events affected by parallax and the closest events without parallax. This distance is used to estimate the probability of missing the preselection of events because of parallax, for any survey characterised by its time sampling and photometric performance. We also define another distance to quantify the detectability of the parallax effect, in order to trigger complementary observations. Results. We find that the preselection of years long time scale events is marginally affected by parallax for all surveys, provided the criteria are reasonably tight. We also show that the parallax should be detectable in the majority of the events found by the LSST survey without follow-up observations.

[31]  arXiv:2003.11326 [pdf, ps, other]

Title: Observations of Ray-Like Structures in Large-Scale Coronal Dimmings Produced by Limb CMEs

Authors: F. Goryaev, V. Slemzin, D. Rodkin

Comments: 21 pages, 12 figures

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

Observations of the off-limb corona with the SWAP wide-field telescope in the 174\,\AA\ passband onboard the PROBA2 mission provide an opportunity to study post-eruptive processes in the dimming regions. We investigate morphology, temporal evolution, and plasma properties for four `deep' off-disk coronal dimmings associated with limb coronal mass ejections (CMEs) in 2010\,--\,2017. Using the SWAP fixed-difference images, we revealed ray-like structures that appeared in the dimming recovery phase stretching quasi-radially to distances from 1.1 to 1.6\,$\mathrm{R}_{\odot}$ and existing from tens of minutes to several hours. Similar rays were detected earlier at distances above 1.7\,$\mathrm{R}_{\odot}$ by the UVCS onboard the SOHO. These structures apparently represent the coronal roots of the flux rope trunks observed by the LASCO-C2 onboard SOHO. The EUVI data onboard the STEREO show the origins of these structures on the disc as fan rays much brighter in the 171\,\AA\ band than in 193\,\AA , which suggests their temperature being less than 2\,MK. The differential emission measure (DEM) analysis based on the AIA multi-wavelength images onboard the SDO showed that the emission measure (EM) in these rays compared to the pre-eruption plasma state increased up to 45\,\% at temperatures of 0.6\,--\,0.8\,MK, whereas EM of the ambient coronal plasma with temperatures of 1.3\,--\,3.7\,MK dropped by 19\,--\,43\,\%. For the event on 18 August 2010, the PLASTIC instrument onboard STEREO detected signatures of the cold streams in the CME tail as enriched with the ions Fe$^{8+}$\,--\,Fe$^{10+}$, which may be associated with the post-eruptive rays in the solar corona.

[32]  arXiv:2003.11387 [pdf, other]

Title: Magnetic Braking at work in binaries

Authors: Walter van Rensbergen, Jean Pierre de Greve

Comments: 6 pages, 2 figures, 2 tables

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

Our binary evolutionary code predicted until now the position of both stars in the HRD, the characteristics of the accretion disk around the gainer in the case that there is enough space between both stars for this disk. Our code includes a complete description of the tidal interaction. The code was now extended with the action of magnetic braking. Without this phenomenon the rotational velocity of the gainer can not be predicted.Magnetic braking and tides act together and the evolution of the equatorial velocity can now be followed up from birth to death of the binary. From Figure (1) in the text one sees that the equatorial velocity is kept most of the time far below critical. When the equatorial velocity is large a magnetic field is created. The subsequent magnetic braking is applied on a large number of binaries for which the equatorial velocity is measured. The result is encouraging: a large fraction of observed equatorial velocities is reproduced by our calculations.

[33]  arXiv:2003.11411 [pdf, other]

Title: Asteroid triple system 2001 SN263 : surfaces characteristics and dynamical environment

Authors: O. C. Winter, G. Valvano, T. S. Moura, G. Borderes-Motta, A. Amarante, R. Sfair

Comments: 22 pages, 16 figures

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

The (153591) 2001 SN263 asteroid system, target of the first Brazilian interplanetary space mission, is one of the known three triple systems within the population of NEAs. One of the mission objectives is to collect data about the formation of this system. The analysis of these data will help in the investigation of the physical and dynamical structures of the components (Alpha, Beta and Gamma) of this system, in order to find vestiges related to its origin. In this work, we assume the irregular shape of the 2001 SN263 system components as uniform density polyhedra and computationally investigate the gravitational field generated by these bodies. The goal is to explore the dynamical characteristics of the surface and environment around each component. Then, taking into account the rotational speed, we analyze their topographic features through the quantities geometric altitude, tilt, geopotential, slope, surface accelerations, among others. Additionally, the investigation of the environment around the bodies made it possible to construct zero-velocity curves, which delimit the location of equilibrium points. The Alpha component has a peculiar number of 12 equilibrium points, all of them located very close to its surface. In the cases of Beta and Gamma, we found four equilibrium points not so close to their surfaces. Then, performing numerical experiments around their equilibrium points, we identified the location and size of just one stable region, which is associated with an equilibrium point around Beta. Finally, we integrated a spherical cloud of particles around Alpha and identified the location on the surface of Alpha were the particles have fallen.

[34]  arXiv:2003.11412 [pdf, ps, other]

Title: A parsec-scale radio jet launched by the central intermediate-mass black hole in the dwarf galaxy SDSS J090613.77+561015.2?

Authors: Jun Yang (1), Leonid I. Gurvits (2, 3 and 4), Zsolt Paragi (2), Sandor Frey (5, 6), John E. Conway (1), Xiang Liu (7), Lang Cui (7) ((1) Chalmers University of Technology, Sweden, (2) JIVE, Netherlands, (3) Delft University of Technology, Netherlands, (4) CSIRO Astronomy and Space Science, Australia, (5) Konkoly Observatory, Hungary, (6) ELTE Eötvös Loránd University, Hungary, (7) Xinjiang Astronomical Observatory, China)

Comments: Accepted for publication as a Letter in MNRAS

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

The population of intermediate-mass black holes (IMBHs) in nearby dwarf galaxies plays an important "ground truth" role in exploring black hole formation and growth in the early Universe. In the dwarf elliptical galaxy SDSS J090613.77+561015.2 (z=0.0465), an accreting IMBH has been revealed by optical and X-ray observations. Aiming to search for possible radio core and jet associated with the IMBH, we carried out very long baseline interferometry (VLBI) observations with the European VLBI Network (EVN) at 1.66 GHz. Our imaging results show that there are two 1-mJy components with a separation of about 52 mas (projected distance 47 pc) and the more compact component is located within the 1-sigma error circle of the optical centroid from available Gaia astrometry. Based on their positions, elongated structures and relatively high brightness temperatures, as well as the absence of star-forming activity in the host galaxy, we argue that the radio morphology originates from the jet activity powered by the central IMBH. The existence of the large-scale jet implies that violent jet activity might occur in the early epochs of black hole growth and thus help to regulate the co-evolution of black holes and galaxies.

[35]  arXiv:2003.11427 [pdf, ps, other]

Title: A two-sided but significantly beamed jet in the supercritical accretion quasar IRAS F11119+3257

Authors: Jun Yang (1), Zsolt Paragi (2), Tao An (3), Willem A. Baan (4 and 5), Prashanth Mohan (3), Xiang Liu (5) ((1) Chalmers University of Technology, Sweden, (2) JIVE, Netherlands, (3) Shanghai Astronomical Observatory, China, (4) ASTRON, Netherlands and (5) Xinjiang Astronomical Observatory, China)

Comments: Accepted for publication in MNRAS

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

Highly accreting quasars are quite luminous in the X-ray and optical regimes. While, they tend to become radio quiet and have optically thin radio spectra. Among the known quasars, IRAS F11119+3257 is a supercritical accretion source because it has a bolometric luminosity above the Eddington limit and extremely powerful X-ray outflows. To probe its radio structure, we investigated its radio spectrum between 0.15 and 96.15 GHz and performed very-long-baseline interferometric (VLBI) observations with the European VLBI Network (EVN) at 1.66 and 4.93 GHz. The deep EVN image at 1.66 GHz shows a two-sided jet with a projected separation about two hundred parsec and a very high flux density ratio of about 290. Together with the best-fit value of the integrated spectral index of -1.31+/-0.02 in the optically thin part, we infer that the approaching jet has an intrinsic speed at least 0.57 times of the light speed. This is a new record among the known all kinds of super-Eddington accreting sources and unlikely accelerated by the radiation pressure. We propose a scenario in which IRAS F11119+3257 is an unusual compact symmetric object with a small jet viewing angle and a radio spectrum peaking at 0.53+/-0.06 GHz mainly due to the synchrotron self-absorption.

[36]  arXiv:2003.11431 [pdf]

Title: Perspectives on atmospheric evolution from noble gas and nitrogen isotopes on Earth, Mars & Venus

Authors: Guillaume Avice, Bernard Marty

Journal-ref: Space Science Reviews 216 (2020) 36

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

The composition of an atmosphere has integrated the geological history of the entire planetary body. However, the long-term evolutions of the atmospheres of the terrestrial planets are not well documented. For Earth, there were until recently only few direct records of atmosphere's composition in the distant past, and insights came mainly from geochemical or physical proxies and/or from atmospheric models pushed back in time. Here we review innovative approaches on new terrestrial samples that led to the determination of the elemental and isotopic compositions of key geochemical tracers, namely noble gases and nitrogen. Such approaches allowed one to investigate the atmosphere's evolution through geological period of time, and to set stringent constraints on the past atmospheric pressure and on the salinity of the Archean oceans. For Mars, we review the current state of knowledge obtained from analyses of Martian meteorites, and from the direct measurements of the composition of the present-day atmosphere by rovers and spacecrafts. Based on these measurements, we explore divergent models of the Martian and Terrestrial atmospheric evolutions. For Venus, only little is known, evidencing the critical need for dedicated missions.

[37]  arXiv:2003.11433 [pdf, other]

Title: HII regions and high-mass starless clump candidates I: Catalogs and properties

Authors: S. Zhang (1), A. Zavagno (1 and 2), J. Yuan (3), H. Liu (4 and 5), M. Figueira (6), D. Russeil (1), F. Schuller (7), K. A. Marsh (8), Y. Wu (9) ((1) Aix Marseille Univ, CNRS, CNES, LAM, Marseille, France, (2) Institut Universitaire de France (IUF), (3) National Astronomical Observatories, Chinese Academy of Sciences, Beijing, China, (4) CASSACA, China-Chile Joint Center for Astronomy, Chile, (5) Departamento de Astronomía, Universidad de Concepción, Chile, (6) National Centre for Nuclear Research, Warszawa, (7) Max-Planck-Institut für Radioastronomie, Bonn, (8) Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, California, (9) Department of Astronomy, Peking University, Beijing, China)

Comments: 28 pages, 32 figures, accepted by Astronomy & Astrophysics on 24, Feb, 2020

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

The role of ionization feedback on high-mass (>8 Msun) star formation (HMSF) is still highly debated. Questions remain concerning the presence of nearby HII regions changes the properties of early HMSF and whether HII regions promote or inhibit the formation of high-mass stars. To characterize the role of HII regions on the HMSF, we study the properties of a sample of candidates high-mass starless clumps (HMSCs), of which about 90% have masses larger than 100 Msun. These high-mass objects probably represent the earliest stages of HMSF; we search if (and how) their properties are modified by the presence of an HII region. We took advantage of the recently published catalog of HMSC candidates. By cross matching the HMSCs and HII regions, we classified HMSCs into three categories: 1) The HMSCs associated with HII regions both in the position in the projected plane of the sky and in velocity; 2) HMSCs associated in the plane of the sky, but not in velocity; and 3) HMSCs far away from any HII regions in the projected sky plane. We carried out comparisons between associated and nonassociated HMSCs based on statistical analyses of multiwavelength data from infrared to radio. Statistical analyses suggest that HMSCs associated with HII regions are warmer, more luminous, more centrally-peaked and turbulent. We also clearly show, for the first time, that the ratio of bolometric luminosity to envelope mass of HMSCs (L/M) could not be a reliable evolutionary probe for early HMSF due to the external heating effects of the HII regions. More centrally peaked and turbulent properties of HMSCs associated with HII regions may promote the formation of high-mass stars by limiting fragmentation. High resolution interferometric surveys toward HMSCs are crucial to reveal how HII regions impact the star formation process inside HMSCs.

[38]  arXiv:2003.11440 [pdf, other]

Title: Diffusive photospheres in gamma-ray bursts

Authors: G. V. Vereshchagin, I. A. Siutsou

Comments: accepted for publication in MNRAS

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

Photospheric emission may originate from relativistic outflows in two qualitatively different regimes:\ last scattering of photons inside the outflow at the photospheric radius, or radiative diffusion to the boundary of the outflow. In this work the measurement of temperature and flux of the thermal component in the early afterglows of several gamma-ray bursts (GRBs) along with the total flux in the prompt phase are used to determine initial radii of the outflow as well as its Lorentz factors. Results indicate that in some cases the outflow has relatively low Lorentz factors $\Gamma<10$, favouring cocoon interpretation, while in other cases Lorentz factors are larger $\Gamma>10$, indicating diffusive photospheric origin of the thermal component, associated with an ultrarelativistic outflow.

[39]  arXiv:2003.11447 [pdf, ps, other]

Title: The M dwarf problem: Fe and Ti abundances in a volume-limited sample of M dwarf stars

Authors: Vincent M .Woolf, George Wallerstein

Comments: 10 pages, 3 figures

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

We report iron and titanium abundance measurements from high resolution spectrain a volume-limited sample of 106 M0 and M0.5 dwarf stars. The sample includesstars north of the celestial equator and closer than 29 parsecs. The results imply thatthere is an M dwarf problem similar to the previously known G dwarf problem, in thatthe fraction of low-metallicity M dwarfs is not large enough to fit simple closed-boxmodels of Galactic chemical evolution. This volume-limited sample avoids many of thestatistical uncertainties present in a previous study using a brightness-limited sampleof M dwarf stars

[40]  arXiv:2003.11481 [pdf, ps, other]

Title: TESS first look at evolved compact pulsators: Known ZZ Ceti stars of the southern ecliptic hemisphere as seen by TESS

Authors: Zs. Bognár, S. D. Kawaler, K. J. Bell, C. Schrandt, A. S. Baran, P. A. Bradley, J. J. Hermes, S. Charpinet, G. Handler, S. E. Mullally, S. J. Murphy, R. Raddi, Á. Sódor, P.-E. Tremblay, M. Uzundag, W. Zong

Comments: 21 pages, 19 figures, accepted for publication in Astronomy & Astrophysics

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

Context. We present our findings on 18 formerly known ZZ Ceti stars observed by the TESS space telescope in 120s cadence mode during the survey observation of the southern ecliptic hemisphere.
Aims. We focus on the frequency analysis of the space-based observations, comparing the results with the findings of the previous ground-based measurements. The frequencies detected by the TESS observations can serve as inputs for future asteroseismic analyses.
Methods. We performed standard pre-whitening of the data sets to derive the possible pulsation frequencies of the different targets. In some cases, we fitted Lorentzians to the frequency groups that emerged as the results of short-term amplitude/phase variations that occurred during the TESS observations.
Results. We detected more than 40 pulsation frequencies in seven ZZ Ceti stars observed in the 120s cadence by TESS, with better than 0.1 microHz precision. We found that HE 0532-5605 may be a new outbursting ZZ Ceti. Ten targets do not show any significant pulsation frequencies in their Fourier transforms, due to a combination of their intrinsic faintness and/or crowding on the large TESS pixels. We also detected possible amplitude/phase variations during the TESS observations in some cases. Such behaviour in these targets was not previously identified from ground-based observations.

[41]  arXiv:2003.11499 [pdf, other]

Title: Giants eating giants: Mass loss and giant planets modifying the luminosity of the Tip of the Giant Branch

Authors: Raul Jimenez, Uffe Grae Jorgensen, Licia Verde

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

During the red giant phase, stars loose mass at the highest rate since birth. The mass-loss rate is not fixed, but varies from star-to-star by up to 5%, resulting in variations of the star's luminosity at the tip of the red giant branch (TRGB). Also, most stars, during this phase, engulf part of their planetary system, including their gas giant planets. Gas giant planet masses range between 0.1 to 2% of the host star mass. The engulfing of their gas giants planets can modify their luminosity at the TRGB, i.e. the point at which the He-core degeneracy is removed. We show that the increase in mass of the star by the engulfing of the gas giant planets only modifies the luminosity of a star at the TRGB by less than 0.1%, while metallicity can modify the luminosity of a star at the TRGB by up to 0.5%. However, the increase in turbulence of the convective envelope of the star, i.e., modification of the mixing length, has a more dramatic effect, on the star's luminosity, which we estimate could be as large as 5%. The effect is always in the direction to increase the turbulence and thus the mixing length which turns into a systematic decrease of the luminosity of the star at the TRGB. We find that the star-to-star variation of the mass-loss rate will dominate the variations in the luminosity of the TRGB with a contribution at the 5% level. If the star-to-star variation is driven by environmental effects --as it is reasonable to assume--, the same effects can potentially create an environmentally-driven mean effect on the luminosity of the tip of the red giant branch of a galaxy. Finally, we touch upon how to infer the frequency, and identify the engulfment, of exoplanets in low-metallicity RGB stars through high resolution spectroscopy as well as how to quantify mass loss rate distributions from the morphology of the horizontal branch.

[42]  arXiv:2003.11534 [pdf, other]

Title: High-energy particles and radiation in star-forming regions

Authors: A.M. Bykov, A. Marcowith, E. Amato, M.E. Kalyashova, J.M.D. Kruijssen, E. Waxman

Comments: 41 pages, Space Science Reviews, topical collection Star Formation

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

Non-thermal particles and high-energy radiation can play a role in the dynamical processes in star-forming regions and provide an important piece of the multiwavelength observational picture of their structure and components. Powerful stellar winds and supernovae in compact clusters of massive stars and OB associations are known to be favourable sites of high-energy particle acceleration and sources of non-thermal radiation and neutrinos. Namely, young massive stellar clusters are likely sources of the PeV (petaelectronvolt) regime cosmic rays (CRs). They can also be responsible for the cosmic ray composition, e.g., 22Ne/20Ne anomalous isotopic ratio in CRs. Efficient particle acceleration can be accompanied by super-adiabatic amplification of the fluctuating magnetic fields in the systems converting a part of kinetic power of the winds and supernovae into the magnetic energy through the CR-driven instabilities. The escape and CR propagation in the vicinity of the sources are affected by the non-linear CR feedback. These effects are expected to be important in starburst galaxies, which produce high-energy neutrinos and gamma-rays. We give a brief review of the theoretical models and observational data on high-energy particle acceleration and their radiation in star-forming regions with young stellar population.

Cross-lists for Thu, 26 Mar 20

[43]  arXiv:2003.10682 (cross-list from gr-qc) [pdf, other]

Title: Not quite black holes as dark matter

Authors: Ufuk Aydemir, Bob Holdom, Jing Ren

Comments: 33 pages, 10 figures

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

Primordial black holes that survive until the present have been considered as a dark matter candidate. In this paper we argue that primordial 2-2-hole remnants provide a more promising and testable option. 2-2-holes arise in quadratic gravity as a new family of classical solutions for ultracompact matter distributions and they possess the black hole exterior without an event horizon. They may serve as the endpoint of gravitational collapse, providing a resolution for the information loss problem. Intriguing thermodynamic behavior is found for these objects when sourced by a thermal gas. A large 2-2-hole radiates with a Hawking-like temperature and exhibits an entropy-area law. At a late stage, the evaporation slows down and essentially stops as the mass asymptotically approaches a minimal value. This remnant mass is determined by a fundamental scale in quadratic gravity. We study the cosmological and astrophysical implications of having these remnants as dark matter and derive the corresponding constraints. A distinctive phenomenon associated with remnant mergers occurs, predicting fluxes of high-energy astrophysical particles due to the spectacular evaporation of the merger product. Measurements of high-energy photon and neutrino fluxes could possibly bound the remnant mass to be not far above the Planck mass. Early-universe physics, on the other hand, requires that 2-2-holes quickly evolve into the remnant state after formation, putting an upper bound on the formation mass.

[44]  arXiv:2003.11375 (cross-list from hep-ph) [pdf, other]

Title: Nonperturbative Flavor Breaking in Topological Susceptibility at Hot QCD Criticality

Authors: Mamiya Kawaguchi, Shinya Matsuzaki, Akio Tomiya

Comments: 5 pages, 3 figures

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

We show that the QCD topological susceptibility nonperturbatively gets a significant contribution signaled by flavor-nonuniversal quark condensates at around the pseudo-critical temperature of the chiral crossover. It implies a remarkable flavor breaking in the axial anomaly as well as the QCD theta vacuum in high temperature QCD, which are (almost) flavor universal in the vacuum. The flavor breaking is triggered by nonperturbative thermal loop corrections, which cannot be dictated by the low-energy expansion associated with the chiral symmetry breaking, such as the chiral perturbation theory. This would give an impact on the thermal history and the cosmological evolution of QCD axion including the estimate of the relic abundance as a cold dark matter candidate. Applications to heavy-ion collision-phenomenology would also be possible.

Replacements for Thu, 26 Mar 20

[45]  arXiv:1604.07845 (replaced) [pdf, other]

Title: Black holes and gravitational waves in models of minicharged dark matter

Authors: Vitor Cardoso, Caio F. B. Macedo, Paolo Pani, Valeria Ferrari

Comments: 19+14 pages, 9 figures, 3 appendices. Supplemental Mathematica notebook available at this http URL v4: Corrects some typos and errors in the published version. Results for the inspiral phase are not affected at qualitative level, the other results are unchanged

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

[46]  arXiv:1609.04576 (replaced) [pdf, other]

Title: Anomalous spectral lines and relic quantum nonequilibrium

Authors: Nicolas G. Underwood, Antony Valentini

Comments: 14 pages, 5 figures. Updated to match published version

Journal-ref: Phys. Rev. D 101, 043004 (2020)

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

[47]  arXiv:1809.09251 (replaced) [pdf, other]

Title: Effects of Redshift Uncertainty on Cross-Correlations of CMB Lensing and Galaxy Surveys

Authors: Ross Cawthon

Comments: 22 pages, 22 figures. Updated to match text published by PRD. Main conclusions unchanged, added Section IX and expanded Section VII D. Presented as a thesis to the Department of Astronomy and Astrophysics, The University of Chicago, in partial fulfillment of the requirements for the Ph.D. degree

Journal-ref: Phys. Rev. D 101, 063509 (2020)

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

[48]  arXiv:1904.04840 (replaced) [pdf, other]

Title: Common origin of modified chaotic inflation, non thermal dark matter and Dirac neutrino mass

Authors: Debasish Borah, Dibyendu Nanda, Abhijit Kumar Saha

Comments: 25 pages, 5 figures, matches version accepted for publication in Phys. Rev. D

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

[49]  arXiv:1906.02293 (replaced) [pdf, other]

Title: The [CII]/[NII] ratio in 3 < z < 6 sub-millimetre galaxies from the South Pole Telescope survey

Authors: D. J. M. Cunningham, S. C. Chapman, M. Aravena, C. De Breuck, M. Béthermin, Chian-Chou Chen, Chenxing Dong, A. H. Gonzalez, T. R. Greve, K. C. Litke, J. Ma, M. Malkan, D. P. Marrone, T. Miller, K. A. Phadke, C. Reuter, K. Rotermund, J. S. Spilker, A. A. Stark, M. Strandet, J. D. Vieira, A. Weiß

Comments: 8 pages, 4 figures, accepted to MNRAS

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

[50]  arXiv:1908.02629 (replaced) [pdf, ps, other]

Title: Second law of thermodynamics in nonminimally coupled gravity

Authors: R.P.L. Azevedo, P.P. Avelino

Comments: 7 pages, 6 figures

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

[51]  arXiv:1909.03077 (replaced) [pdf, other]

Title: The Population of Galaxies that Contribute to The HI Mass Function

Authors: Saili Dutta, Nishikanta Khandai, Biprateep Dey

Comments: 17 pages, 10 figures, 3 tables, Accepted in MNRAS

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

[52]  arXiv:1910.10134 (replaced) [pdf, other]

Title: Stellar Density Profiles of Dwarf Spheroidal Galaxies

Authors: A.G. Moskowitz, M.G. Walker

Comments: 25 pages, 17 figures. Published in ApJ

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

[53]  arXiv:1911.05086 (replaced) [pdf, other]

Title: The Cosmological Evolution of Light Dark Photon Dark Matter

Authors: Samuel D. McDermott, Samuel J. Witte

Comments: v2: Published version. Added 3 plots and appendix to justify lack of back reaction and the importance of cooling mechanism. Corrected small bug. v1: 11 pages, 5 figures. Ancillary file containing strongest constraint at each dark photon mass included to ease reproduction of bounds

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

[54]  arXiv:1911.06163 (replaced) [pdf, other]

Title: Contribution of starburst nuclei to the diffuse gamma-ray and neutrino flux

Authors: Enrico Peretti, Pasquale Blasi, Felix Aharonian, Giovanni Morlino, Pierre Cristofari

Comments: Version accepted for publication in MNRAS, 13 pages, 5 figures

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

[55]  arXiv:1911.09706 (replaced) [pdf, other]

Title: Density and temperature of cosmic-web filaments on scales of tens of megaparsecs

Authors: H. Tanimura, N. Aghanim, V. Bonjean, N. Malavasi, M. Douspis

Comments: 11 pages, 9 figures, accepted for publication by A&A

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

[56]  arXiv:1911.10609 (replaced) [pdf, other]

Title: Tension of the $E_G$ statistic and RSD data with Planck/$Λ$CDM and implications for weakening gravity

Authors: F. Skara, L. Perivolaropoulos

Comments: 24 pages, 10 Figures. Published extended version (3 additional figures, additional less correlated dataset analysed). The data and the Mathematica data analysis files may be downloaded from this http URL

Journal-ref: Phys. Rev. D 101, 063521 (2020)

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)

[57]  arXiv:1912.02415 (replaced) [pdf, other]

Title: Modelling Double Neutron Stars: Radio and Gravitational Waves

Authors: Debatri Chattopadhyay, Simon Stevenson, Jarrod R. Hurley, Luca J. Rossi, Chris Flynn

Comments: 26 pages, Accepted for publication by MNRAS

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

[58]  arXiv:1912.09740 (replaced) [pdf, other]

Title: A Walking Dilaton Inflation

Authors: Hiroyuki Ishida, Shinya Matsuzaki

Comments: 10 pages, 1 figure; references and footnotes added; some discussion added,version published in PLB

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

[59]  arXiv:2001.04962 (replaced) [pdf, other]

Title: Temperatures and Metallicities of M dwarfs in the APOGEE Survey

Authors: Jessica Birky, David W. Hogg, Andrew W. Mann, Adam Burgasser

Journal-ref: Astrophysical Journal, 892, 1 (2020)

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

[60]  arXiv:2001.05393 (replaced) [pdf, other]

Title: Forecast for cosmological parameter estimation with gravitational-wave standard siren observation from the Cosmic Explorer

Authors: Shang-Jie Jin, Dong-Ze He, Yidong Xu, Jing-Fei Zhang, Xin Zhang

Comments: 17 pages, 4 figures

Journal-ref: JCAP 03 (2020) 051

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

[61]  arXiv:2001.06494 (replaced) [pdf, other]

Title: Turbulence in stratified atmospheres: implications for the intracluster medium

Authors: Rajsekhar Mohapatra, Christoph Federrath, Prateek Sharma

Comments: MNRAS accepted version. For simulation movies see: this https URL

Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Atmospheric and Oceanic Physics (physics.ao-ph); Fluid Dynamics (physics.flu-dyn)

[62]  arXiv:2002.00983 (replaced) [pdf, other]

Title: The Birth of Binary Direct-Collapse Black Holes

Authors: Muhammad A. Latif, Sadegh Khochfar, Daniel Whalen

Comments: Published in ApJL, this https URL

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

[63]  arXiv:2002.02130 (replaced) [pdf, other]

Title: First SETI Observations with China's Five-hundred-meter Aperture Spherical radio Telescope (FAST)

Authors: Zhi-Song Zhang, Dan Werthimer, Tong-Jie Zhang, Jeff Cobb, Eric Korpela, David Anderson, Vishal Gajjar, Ryan Lee, Shi-Yu Li, Xin Pei, Xin-Xin Zhang, Shi-Jie Huang, Pei Wang, Yan Zhu, Ran Duan, Hai-Yan Zhang, Cheng-jin Jin, Li-Chun Zhu, Di Li

Comments: 21 pages, 19 figures, 3 tables, published in ApJ

Journal-ref: The Astrophysical Journal, Volume 891, Issue 2, id.174(2020)

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

[64]  arXiv:2003.01644 (replaced) [pdf, other]

Title: The Imprint of the Protoplanetary Disk in the Accretion of Super-Earth Envelopes

Authors: Mohamad Ali-Dib, Andrew Cumming, Douglas N. C. Lin

Comments: 10 pages, 6 figures, accepted for publication in MNRAS

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

[65]  arXiv:2003.01882 (replaced) [pdf, ps, other]

Title: Constraining the Neutrino Mass with the Drifting Coefficient of the Field Cluster Mass Function

Authors: Suho Ryu, Jounghun Lee (Seoul National University)

Comments: accepted for publication in ApJ, 7 figures, minor revision

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

[66]  arXiv:2003.02778 (replaced) [pdf, other]

Title: The Evolution of Primordial Black Holes and their Final Observable Spins

Authors: V. De Luca, G. Franciolini, P. Pani, A. Riotto

Comments: 13 figures, 31 pages. v2: Section and appendix added. Results unchanged

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

[67]  arXiv:2003.05472 (replaced) [pdf, other]

Title: Concerns about ground based astronomical observations: quantifying satellites' constellations damages

Authors: Stefano Gallozzi (1), Diego Paris (1), Marco Scardia (2), (3) David Dubois ((1) INAF-Osservatorio Astronomico di Roma, (2) INAF-Osservatorio Astronomici di Brera, (3) NASA-National Aeronautics and Space Administration)

Comments: 23 pages, 27 figures, 4 tables and 1 algorithm. arXiv admin note: text overlap with arXiv:1904.00502 by other authors

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

[68]  arXiv:2003.06874 (replaced) [pdf, other]

Title: A dark matter telescope probing the 6 to 60 GHz band

Authors: Javier De Miguel Hernández

Comments: 25 pages, 7 figures

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

[69]  arXiv:2003.08848 (replaced) [pdf, ps, other]

Title: Subaru medium-resolution spectra of a QSO at z=6.62: Three reionization tests

Authors: Ting-Yi Lu, Tomotsugu Goto, Ji-Jia Tang, Tetsuya Hashimoto, Yi-Hang Valerie Wong, Chia-Ying Chang, Yi-Han Wu, Seong Jin Kim, Chien-Chang Ho, Ting-Wen Wang, Alvina Y. L. On, Daryl Joe D. Santos

Comments: 11 pages, 10 figures, 5 tables, Accepted for Publication in ApJ

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

[70]  arXiv:2003.08924 (replaced) [pdf, ps, other]

Title: Interpreting solar wind turbulent spectra beyond Taylor's Hypothesis

Authors: Sofiane Bourouaine, Jean C Perez

Comments: Accepted for publication in ApJL

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

[71]  arXiv:2003.09341 (replaced) [pdf, ps, other]

Title: High-redshift cosmography: auxiliary variables versus Padé polynomials

Authors: Salvatore Capozziello, Rocco D'Agostino, Orlando Luongo

Comments: 17 pages, 3 figures, to appear in MNRAS

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

[72]  arXiv:2003.10326 (replaced) [pdf, other]

Title: The explanation for the mysterious hot solar corona

Authors: Anil Narayan Raghav

Comments: 5 pages, 1 Figure

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

[73]  arXiv:2003.10583 (replaced) [pdf, other]

Title: On rising magnetic flux tube and formation of sunspots in a deep domain

Authors: H. Hotta, H. Iijima

Comments: 17 pages, 24 figures. Accepted for publication by MNRAS

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

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