We gratefully acknowledge support from
the Simons Foundation and Leiden University.

Astrophysics

New submissions

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New submissions for Tue, 26 Nov 19

[1]  arXiv:1911.10204 [pdf, other]
Title: Astronomy and the new SI
Authors: Prasenjit Saha
Comments: To appear as a Topical Review in PASP
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

In 2019 the International System of units (SI) conceptually re-invented itself. This was necessary because quantum-electronic devices had become so precise that the old SI could no longer calibrate them. The new system defines values of fundamental constants (including $c,h,k,e$ but not $G$) and allows units to be realized from the defined constants through any applicable equation of physics. In this new and more abstract SI, units can take on new guises --- for example, the kilogram is at present best implemented as a derived electrical unit. Relevant to astronomy, however, is that several formerly non-SI units, such as electron-volts, light-seconds, and what we may call "gravity seconds" $GM/c^3$, can now be interpreted not as themselves units, but as shorthand for volts and seconds being used with particular equations of physics. Moreover, the classical astronomical units have exact and rather convenient equivalents in the new SI: zero AB magnitude amounts to $\simeq5\times10^{10}$ photons $\rm m^{-2}\,s^{-1}$ per logarithmic frequency or wavelength interval, $\rm 1\,au\simeq 500$ light-seconds, $\rm 1\,pc\simeq 10^8$ light-seconds, while a solar mass $\simeq5$ gravity-seconds. As a result, the unit conversions ubiquitous in astrophysics can now be eliminated, without introducing other problems, as the old-style SI would have done. We review a variety of astrophysical processes illustrating the simplifications possible with the new-style SI, with special attention to gravitational dynamics, where care is needed to avoid propagating the uncertainty in $G$. Well-known systems (GPS satellites, GW170817, and the M87 black hole) are used as examples wherever possible.

[2]  arXiv:1911.10211 [pdf, other]
Title: The effect of diffuse background on the spatially-resolved Schmidt relation in nearby spiral galaxies
Comments: 33 pages, 25 figures, 6 tables, accepted for publication in A&A
Subjects: Astrophysics of Galaxies (astro-ph.GA)

The global Schmidt law of star formation provides a power-law relation between the surface densities of star-formation rate (SFR) and gas, and successfully explains plausible scenarios of galaxy formation and evolution. However, star formation being a multi-scale process, requires spatially-resolved analysis for a better understanding of the physics of star formation. It has been shown that the removal of a diffuse background from SFR tracers, such as H$\alpha$, far-ultraviolet (FUV), infrared, leads to an increase in the slope of the sub-galactic Schmidt relation. We reinvestigate the local Schmidt relations in nine nearby spiral galaxies taking into account the effect of inclusion and removal of diffuse background in SFR tracers as well as in the atomic gas.We used multiwavelength data obtained as part of the surveys such as SINGS, KINGFISH, THINGS, and HERACLES. Making use of a novel split of the overall light distribution as a function of spatial scale, we subtracted the diffuse background in the SFR tracers as well as the atomic gas. Using aperture photometry, we study the Schmidt relations on background subtracted and unsubtracted data at physical scales varying between 0.5--2 kpc. The fraction of diffuse background varies from galaxy to galaxy and accounts to $\sim$34 % in H$\alpha$, $\sim$43 % in FUV, $\sim$37 % in 24 $\mu$m, and $\sim$75\% in H I on average. We find that the inclusion of diffuse background in SFR tracers leads to a linear molecular gas Schmidt relation and a bimodal total gas Schmidt relation. However, the removal of diffuse background in SFR tracers leads to a super-linear molecular gas Schmidt relation. A further removal of the diffuse background from atomic gas results in a slope $\sim$1.4 $\pm$ 0.1, which agrees with dynamical models of star formation accounting for flaring effects in the outer regions of galaxies.

[3]  arXiv:1911.10212 [pdf, other]
Title: Ionised gas outflow signatures in SDSS-IV MaNGA active galactic nuclei
Comments: 16 pages, submitted to MNRAS and reviewer's comments addressed
Subjects: Astrophysics of Galaxies (astro-ph.GA)

The prevalence of outflow and feedback signatures in active galactic nuclei (AGN) is a major unresolved question which large integral field unit (IFU) surveys now allow to address. In this paper, we present a kinematic analysis of the ionised gas in 2778 galaxies at z $\sim$ 0.05 observed by SDSS-IV MaNGA. Specifically, we measure the kinematics of the [OIII] {\lambda}5007{\AA} emission line in each spatial element and fit multiple Gaussian components to account for possible non-gravitational motions of gas. Comparing the kinematics of the ionised gas between 308 MaNGA-selected AGN that have been previously identified through emission line diagnostics and sources not classified as AGN, we find that while 25% of MaNGA-selected AGN show [OIII] components with emission line widths of $>$ 500 km/s in more than 10% of their spaxels, only 7% of MaNGA non-AGN show a similar signature. Even the AGN that do not show nuclear AGN photoionisation signatures and that were only identified as AGN based on their larger scale photoionisation signatures show similar kinematic characteristics. In addition to obscuration, another possibility is that outflow and mechanical feedback signatures are longer lived than the AGN itself. Our measurements demonstrate that high velocity gas is more prevalent in AGN compared to non-AGN and that outflow and feedback signatures in low-luminosity, low-redshift AGN may so far have been underestimated. We show that higher luminosity MaNGA-selected AGN are able to drive larger scale outflows than lower luminosity AGN. But estimates of the kinetic coupling efficiencies are $<$ 1% and suggest that the feedback signatures probed in this paper are unlikely to have a significant impact on the AGN host galaxies. However, continuous energy injection may still heat a fraction of the cool gas and delay or suppress star formation in individual galaxies even when the AGN is weak.

[4]  arXiv:1911.10216 [pdf, other]
Title: First Season MWA Phase II EoR Power Spectrum Results at Redshift 7
Comments: 26 pages, 15 figures, 3 tables. Matches version accepted to ApJ
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

The compact configuration of Phase II of the Murchison Widefield Array (MWA) consists of both a redundant subarray and pseudo-random baselines, offering unique opportunities to perform sky-model and redundant interferometric calibration. The highly redundant hexagonal cores give improved power spectrum sensitivity. In this paper, we present the analysis of nearly 40 hours of data targeting one of the MWA's EoR fields observed in 2016. We use both improved analysis techniques presented in Barry et al. (2019) as well as several additional techniques developed for this work, including data quality control methods and interferometric calibration approaches. We show the EoR power spectrum limits at redshift 6.5, 6.8 and 7.1 based on our deep analysis on this 40-hour data set. These limits span a range in $k$ space of $0.18$ $h$ $\mathrm{Mpc^{-1}}$ $<k<1.6$ $h$ $\mathrm{Mpc^{-1}}$, with a lowest measurement of $\Delta^2\leqslant2.39\times 10^3$ $\mathrm{mK}^2$ at $k=0.59$ $h$ $\mathrm{Mpc^{-1}}$ and $z=6.5$.

[5]  arXiv:1911.10253 [pdf, ps, other]
Title: Variable warm dust around the Herbig Ae star HD~169142: Birth of a ring?
Comments: 7 pages, 3 figures. Accepted to ApJ Letters
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

The Herbig Ae star HD 169142 is known to have a gaseous disk with a large inner hole, and also a photometrically variable inner dust component in the sub-au region. Following up our previous analysis, we further studied the temporal evolution of inner dust around HD 169142, which may provide information on the evolution from late-stage protoplanetary disks to debris disks. We used near-infrared interferometric observations obtained with VLTI/PIONIER to constrain the dust distribution at three epochs spanning six years. We also studied the photometric variability of HD 169142 using our optical-infrared observations and archival data. Our results indicate that a dust ring at ~0.3 au formed at some time between 2013 and 2018, and then faded (but did not completely disappear) by 2019. The short-term variability resembles that observed in extreme debris disks, and is likely related to short-lived dust of secondary origin, though variable shadowing from the inner ring could be an alternative interpretation. If confirmed, this is the first direct detection of secondary dust production inside a protoplanetary disk.

[6]  arXiv:1911.10265 [pdf, other]
Title: Science Opportunities from Observations of the Interstellar Neutral Gas with Adjustable Boresight Direction
Comments: 15 figures, 3 tables, 26 pages; Accepted for publication in The Astrophysical Journal Supplement Series
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

The interstellar neutral (ISN) gas enters the heliosphere and is detected at few au from the Sun, as demonstrated by Ulysses and the Interstellar Boundary Explorer (IBEX) missions. Ulysses observed ISN gas from different vantage points in a polar orbit from 1994 to 2007, while IBEX has been observing in an Earth's orbit in a fixed direction relative to the Sun from 2009. McComas et al. 2018 reported about an IMAP-Lo detector onboard the Interstellar Mapping and Acceleration Probe (IMAP), with an ability to track the ISN flux in the sky. We present observation geometries for ISN gas for a detector with the capability to adjust the boresight direction along the Earth orbit over a year within a multi-choice ISN observation scheme. We study science opportunities from the observations as a function of time during a year and the phase of solar activity. We identify observation geometries and determine the observation seasons separately for various ISN species and populations. We find that using an adjustable viewing direction allows for ISN gas observations in the upwind hemisphere, where the signal is not distorted by gravitational focusing, in addition to the viewing of ISN species throughout the entire year. Moreover, we demonstrate that with appropriately adjusted observation geometries, primary and secondary populations can be fully separated. Additionally, we show that atoms of ISN gas on indirect trajectories are accessible for detection and we present their impact on the study of the ionization rates for ISN species.

[7]  arXiv:1911.10271 [pdf, other]
Title: The evolution of Astronomical Observatory design
Comments: 10 pages, 3 figures
Journal-ref: Journal of the Korean Astronomical Society, 52, 99-108 (2019)
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

This work addresses the development of the astronomical observatory all through history, from an architectural point of view, as a building in relation to the observing instruments and their functioning as a heterogeneous work center. We focused on 32 observatories (in the period 1259-2007) and carefully analyzed the architectures. Considering the impact of the construction itself or its facilities on the results of the research (thermal or structural stability, poor weather protection, turbulence, etc.), there is little attention paid to theories or studies of the architectural or construction aspects of the observatories. Therefore, this work aims to present a theoretical-critical contribution that, at least, invites the reflection of those involved in the development of astronomical observatories in the future.

[8]  arXiv:1911.10277 [pdf, other]
Title: Formation of compact systems of super-Earths via dynamical instabilities and giant impacts
Comments: 29 pages, 32 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

NASA's Kepler mission discovered $\sim700$ planets in multi-planet systems containing 3 or more transiting bodies, many of which are super-Earths and mini-Neptunes in compact configurations. Using $N$-body simulations, we examine the in situ, final stage assembly of multi-planet systems via the collisional accretion of protoplanets. Our initial conditions are constructed using a subset of the Kepler 5-planet systems as templates. Two different prescriptions for treating planetary collisions are adopted. The simulations address numerous questions: do the results depend on the accretion prescription?; do the resulting systems resemble the Kepler systems, and do they reproduce the observed distribution of planetary multiplicities when synthetically observed?; do collisions lead to significant modification of protoplanet compositions, or to stripping of gaseous envelopes?; do the eccentricity distributions agree with those inferred for the Kepler planets? We find the accretion prescription is unimportant in determining the outcomes. The final planetary systems look broadly similar to the Kepler templates adopted, but the observed distributions of planetary multiplicities or eccentricities are not reproduced, because scattering does not excite the systems sufficiently. In addition, we find that $\sim 1$% of our final systems contain a co-orbital planet pair in horseshoe or tadpole orbits. Post-processing the collision outcomes suggests they would not significantly change the ice fractions of initially ice-rich protoplanets, but significant stripping of gaseous envelopes appears likely. Hence, it may be difficult to reconcile the observation that many low mass Kepler planets have H/He envelopes with an in situ formation scenario that involves giant impacts after dispersal of the gas disc.

[9]  arXiv:1911.10281 [pdf, other]
Title: Extracting galaxy merger timescales I: Tracking haloes with WhereWolf and spinning orbits with OrbWeaver
Comments: 22 pages, 24 figures, accepted for publication in MNRAS
Subjects: Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)

Hierarchical models of structure formation predict that dark matter halo assembly histories are characterised by episodic mergers and interactions with other haloes. An accurate description of this process will provide insights into the dynamical evolution of haloes and the galaxies that reside in them. Using large cosmological N-body simulations, we characterise halo orbits to study the interactions between substructure haloes and their hosts, and how different evolutionary histories map to different classes of orbits. We use two new software tools - WhereWolf, which uses halo group catalogues and merger trees to ensure that haloes are tracked accurately in dense environments, and OrbWeaver, which quantifies each halo's orbital parameters. We demonstrate how WhereWolf improves the accuracy of halo merger trees, and we use OrbWeaver to quantify orbits of haloes. We assess how well analytical prescriptions for the merger timescale from the literature compare to measured merger timescales from our simulations and find that existing prescriptions perform well, provided the ratio of substructure-to-host mass is not too small. In the limit of small substructure-to-host mass ratio, we find that the prescriptions can overestimate the merger timescales substantially, such that haloes are predicted to survive well beyond the end of the simulation. This work highlights the need for a revised analytical prescription for the merger timescale that more accurately accounts for processes such as catastrophic tidal disruption.

[10]  arXiv:1911.10318 [pdf, ps, other]
Title: The circumstellar environment around the embedded protostar EC 53
Comments: 28 pages, 15 figures, 2 tables, accepted for publication in ApJ
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

EC53 is an embedded protostar with quasi-periodic emission in the near-IR and sub-mm. We use ALMA high-resolution observations of continuum and molecular line emission to describe the circumstellar environment of EC 53. The continuum image reveals a disk with a flux that suggests a mass of 0.075 Msun, much less than the estimated mass in the envelope, and an in-band spectral index that indicates grain growth to centimeter sizes. Molecular lines trace the outflow cavity walls, infalling and rotating envelope, and/or the Keplerian disk. The rotation profile of the C17O 3-2 line emission cannot isolate the Keplerian motion clearly although the lower limit of the protostellar mass can be calculated as 0.3 +- 0.1 Msun if the Keplerian motion is adopted. The weak CH3OH emission, which is anti-correlated with the HCO+ 4-3 line emission, indicates that the water snow line is more extended than what expected from the current luminosity, attesting to bygone outburst events. The extended snow line may persist for longer at the disk surface because the lower density increases the freeze-out timescale of methanol and water.

[11]  arXiv:1911.10320 [pdf, other]
Title: Opportunities and Outcomes for Postdocs in Canada
Comments: State of the profession white paper submitted to the Canadian Long Range Plan 2020 decadal survey with appendices
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Physics and Society (physics.soc-ph)

Currently, postdoctoral fellow (PDF) researchers in Canada face challenges due to the precarious nature of their employment and their overall low compensation and benefits coverage. This report presents three themes, written as statements of need, to support an inclusive and thriving PDF community. These themes are the need for better terms of employment and conditions, the need for access to grants by non-permanent research staff, and the need for a sustainable PDF hiring model that considers the outcomes for the PDFs.
We make six recommendations:
R1. PDFs should be hired and compensated as skilled experts in their areas, not as trainees.
R2. Standard PDF hiring practices should be revised to be more inclusive of different life circumstances.
- R2.1 Allow PDFs the option of part-time employment.
- R2.2 Remove years-since-PhD time limits from PDF jobs.
- R2.3 Financially support PDF hires for relocation and visa expenses.
R3. CASCA should form a committee to advocate for and provide support to astronomy PDFs in Canada.
R4. CASCA should encourage universities to create offices dedicated to their PDFs.
R5. PDFs and other PhD-holding term researchers with a host institution should be able to compete for and win grants to self-fund their own research.
R6. Astronomy in Canada should hire general-purpose continuing support scientist positions instead of term PDFs to fill project or mission-specific requirements.
In short, we ask for prioritization of people over production of papers.

[12]  arXiv:1911.10348 [pdf, other]
Title: Distribution and spectrophotometric classification of basaltic asteroids
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

We aim to determine the distribution of basaltic asteroids (classified as V-types) based on the spectrophotometric data reported in the MOVIS-C catalogue. A total of 782 asteroids were identified. The observations with all four filters (Y, J, H, Ks), available for 297 of these candidates, allow a reliable comparison with the laboratory data of howardite, eucrite, and diogenite meteorites.
We found that the majority of the basaltic candidates ($\approx$ 95$\%$) are located in the inner main belt, while only 29 ($\approx$ 4$\%$) and 8 ($\approx$ 1$\%$) are located in the middle and outer main belt, respectively. A fraction of $\approx$ 33$\%$ from the V-type candidates is associated with the Vesta family (with respect to AstDyS). We also identified four middle main belt V-type candidates belonging to (15) Eunomia family, and another four low inclination ones corresponding to (135) Hertha.
We report differences between the color indices and albedo distributions of the V-type candidates located in the inner main belt compared to those from the middle and outer main belt. These results support the hypothesis of a different origin for the basaltic asteroids with a semi-major axis beyond 2.5 A.U. Furthermore, lithological differences are present between the vestoids and the inner low inclination basaltic asteroids.
The data allow us to estimate the unbiased distribution of basaltic asteroids across the main asteroid belt. We highlight that at least 80$\%$ of the ejected basaltic material from (4) Vesta is missing or is not yet detected because it is fragmented in sizes smaller than 1 km.

[13]  arXiv:1911.10369 [pdf, other]
Title: ExoMol molecular line lists XXXV: a rotation-vibration line list for hot ammonia
Journal-ref: Monthly Notices of the Royal Astronomical Society, 490, 4638-4647 (2019)
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)

A new hot line list for $^{14}$NH$_3$ is presented. The line list CoYuTe was constructed using an accurate, empirically refined potential energy surface and a CCSD(T)/aug-cc-pVQZ ab initio dipole moment surface of ammonia, previously reported. The line list is an improvement of the ammonia line list BYTe [Yurchenko et al., Mon. Not. R. Astron. Soc., 413, 1828 (2011)]. The CoYuTe line list covers wavenumbers up to 20000 cm$^{-1}$, i.e. wavelengths beyond 0.5 $\mu$m for temperatures up to 1500 K. Comparisons with the high temperature experimental data from the literature show excellent agrement for wavenumbers below 6000 cm$^{-1}$. The CoYuTe line list contains 16.9 billion transitions and is available from the ExoMol website (www.exomol.com) and the CDS database.

[14]  arXiv:1911.10377 [pdf, other]
Title: Modeling spectral lags in active galactic nucleus flares in the context of Lorentz invariance violation searches
Comments: 14 pages, 13 figures, 1 appendix. Accepted by A&A
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

High-energy photons emitted by flaring active galactic nuclei (AGNs) have been used for many years to constrain modified dispersion relations in vacuum encountered in the context of quantum gravity phenomenology. In such studies, done in the GeV-TeV range, energy-dependent delays (spectral lags) are searched for, usually neglecting any source-intrinsic time delay. With the aim being to distinguish lorentz invariance violation (LIV) effects from lags generated at the sources themselves, a detailed investigation into intrinsic spectral lags in flaring AGNs above 100 GeV is presented in the frame of synchrotron-self-Compton (SSC) scenarios for their very-high-energy (VHE) emission. A simple model of VHE flares in blazars is proposed, allowing to explore the influence of the main physical parameters describing the emitting zones on intrinsic delays. For typical conditions expected in TeV blazars, significant intrinsic lags are obtained, which can dominate over LIV effects, especially at low redshifts, and should therefore be carefully disentangled from any extrinsic lags. Moreover, two main regimes are identified with characteristic spectral lags, corresponding to long-lasting and fast particle acceleration. Such intrinsic spectral lags should be detected with new-generation instruments at VHE such as the Cherenkov Telescope Array which begins operation in a few years. This will provide original constraints on AGN flare models and open a new era for LIV searches in the photon sector.

[15]  arXiv:1911.10413 [pdf, ps, other]
Title: New version of the Baade--Becker--Wesselink method based on multiphase effective temperature measurements of Cepheids
Comments: 7 pages, 2 figures
Subjects: Astrophysics of Galaxies (astro-ph.GA)

A new version of the Baade--Becker--Wesselink (hereafter BBW) method is proposed, based on direct spectroscopic measurements of effective temperatures of 45 northern Cepheids, made in different pulsating phases. By comparing the temperature estimates obtained from the calibration of effective temperature by normal color with real temperature measurements we were able not only to determine the color excess with an accuracy of 0.01 mag, but also to derive new color calibration of the effective temperature immediately for all available measurements with taking into account the differences in [Fe/H] and log g values: log Teff = 3.88 - 0.20 (B-V)o + 0.026 (B-V)o^2 + 0.009 log g - 0.010 (B-V)o log g - 0.051 [Fe/H] + 0.051 (B-V)o [Fe/H], which is accurate to about 1.1%. We also showed the complete identity of the two main versions of the BBW technique: surface brightness method proposed by Barnes and Evans (1976) and maximum likelyhood method of Balona (1977), refined later by Rastorguev and Dambis (2010).

[16]  arXiv:1911.10424 [pdf, other]
Title: Inflationary magnetogenesis with helical coupling
Comments: 5 pages, 1 figure. This work is based on the results presented at the XI Bolyai-Gauss-Lobachevskii (BGL-2019) Conference: Non-Euclidean, Noncommutative Geometry and Quantum Physics, Kiev, May 19-24. Compared to arXiv:1902.05894, a smooth analytic interpolating coupling function is used with an exact solution
Journal-ref: Ukr. J. Phys. 64, No. 11, pp. 1009-1013 (2019)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)

We describe a simple scenario of inflationary magnetogenesis based on a helical coupling to electromagnetism. It allows to generate helical magnetic fields of strength of order up to $10^{- 7}\,\text{G}$, when extrapolated to the current epoch, in a narrow spectral band centered at any physical wavenumber by adjusting the model parameters. Additional constraints on magnetic fields arise from the considerations of baryogenesis and, possibly, from the Schwinger effect of creation of charged particle-antiparticle pairs.

[17]  arXiv:1911.10451 [pdf]
Title: Interaction Mechanism and Response of Tidal Effect on the Shallow Geology of Europa
Authors: Yifei Wang
Comments: 9 pages,5 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

Europa has been conf irmed to have a multilayered structure and complex geological condition in last two decades whose detail and cause of formation remains unclear.In this work,we start from analyzing the mechanism of tidal ef fect on satellite's surface and discuss if interaction like tidal locking and orbital resonance play an important role in tidal ef fect including heating,underground convection and eruption.During discussion we propose the main factors affecting Europa's tidal heat and the formation mechanism of typical shallow geological features,and provide theoretical support for further exploration.

[18]  arXiv:1911.10467 [pdf, other]
Title: Aggregate Growth and Internal structures of Chondrite Parent Bodies Forming from Dense Clumps
Comments: 24 pages, 17 figures, accepted for publication in ApJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

Major components of chondrites are chondrules and matrix. Measurements of the volatile abundance in Semarkona chondrules suggest that chondrules formed in a dense clump that had a higher solid density than the gas density in the solar nebula. We investigate collisions between chondrules and matrix in the surface region of dense clumps using fluffy aggregate growth models. Our simulations show that the collisional growth of aggregates composed of chondrules and matrix takes place in the clumps well before they experience gravitational collapse. The internal structure of chondrite parent bodies (CPBs) can be thereby determined by aggregate growth. We find that the aggregate growth generates two scales within CPBs. The first scale is involved with the small scale distribution of chondrules and determined by the early growth stage, where chondrules accrete aggregates composed of matrix grains. This accretion can reproduce the thickness of the matrix layer around chondrules found in chondrites. The other scale is related to the large scale distribution of chondrules. Its properties (e.g., the abundance of chondrules and the overall size) depend on the gas motion within the clump, which is parameterized in this work. Our work thus suggests that the internal structure of CPBs may provide important clues about their formation conditions and mechanisms.

[19]  arXiv:1911.10542 [pdf, other]
Title: The unity of dark matter and dark energy in a curvaton scenario
Comments: 25 pages, 3 figures
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

According to the whole evolution of curvaton, we systematically investigate a broad new class of curvaton scenarios supplying a unified framework for dark matter and dark energy, in which the effective mass of curvaton is running (its potential consists of coupling part and exponential part). In this scenario, the coupling is between the curvaton and inflaton. Consequently, we adopt the narrow and broad resonance to study the production of curvation in terms of preheating, whose criteria comes via the spectral index of curvaton. While the inflaton decay, the effective mass varies which plays a role of a free parameter as showing in Ref.~\cite{Tenkanen:2019aij}, moreover one always finds the satisfied combinations of the Hubble parameter and the mass of curvaton. Therefore, it naturally explains the abundance of dark matter. At the very late time of Universe, the inflaton and the curvaton almost decay, the exponential potential of curvaton will be approaching a constant of order of dark energy. As a consequence, it naturally explains the dark energy. In order to elaborate this scenario, we implement the $\delta N$ formalism to calculate the local Non-Gaussianity parameter $f_{NL}$ and the power spectrum $P_\zeta$ of curvaton. Remarkably, our calculation shows that these two observables are independent of potential of inflaton. Once the constraints are given, these two observable are consistent with the observations.

[20]  arXiv:1911.10569 [pdf, other]
Title: Population-Level Eccentricity Distributions of Imaged Exoplanets and Brown Dwarf Companions: Dynamical Evidence for Distinct Formation Channels
Comments: Accepted to AJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

The orbital eccentricities of directly imaged exoplanets and brown dwarf companions provide clues about their formation and dynamical histories. We combine new high-contrast imaging observations of substellar companions obtained primarily with Keck/NIRC2 together with astrometry from the literature to test for differences in the population-level eccentricity distributions of 27 long-period giant planets and brown dwarf companions between 5-100 AU using hierarchical Bayesian modeling. Orbit fits are performed in a uniform manner for companions with short orbital arcs; this typically results in broad constraints for individual eccentricity distributions, but together as an ensemble these systems provide valuable insight into their collective underlying orbital patterns. The shape of the eccentricity distribution function for our full sample of substellar companions is approximately flat from e=0-1. When subdivided by companion mass and mass ratio, the underlying distributions for giant planets and brown dwarfs show significant differences. Low mass ratio companions preferentially have low eccentricities, similar to the orbital properties of warm Jupiters found with radial velocities and transits. We interpret this as evidence for in situ formation on largely undisturbed orbits within massive, extended disks. Brown dwarf companions exhibit a broad peak at e $\approx$ 0.6-0.9 with evidence for a dependence on orbital period. This closely resembles the orbital properties and period-eccentricity trends of wide (1-200 AU) stellar binaries, suggesting that brown dwarfs in this separation range predominantly form in a similar fashion. We also report evidence that the "eccentricity dichotomy" observed at small separations extends to planets on wide orbits: the mean eccentricity for the multi-planet system HR 8799 is lower than for systems with single planets. (Abridged)

[21]  arXiv:1911.10585 [pdf, other]
Title: Prospects for Directly Imaging Young Giant Planets at Optical Wavelengths
Comments: 25 pages, 14 figures, 3 tables, submitted to ApJ review pending
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

In this work, we investigate the properties of young giant planet spectra in the optical and suggest that future space-based direct imaging missions should be considering young planets as a valuable and informative science case. While young planets are dimmer in the optical than in the infrared, they can still be brighter in the optical than a mature planet of similar mass. Therefore, an instrument designed to characterize mature planets should also be suitable for high-precision photometric imaging and spectroscopy of young self-luminous planets in a wavelength range and at a contrast ratio not attainable from the ground. We identify known young self-luminous companions which are feasible targets for WFIRST-CGI and compute spectra for them, including a treatment of scattering and reflected light at optical wavelengths. Using these results, we highlight potentially diagnostic spectral features that will be present in the WFIRST-CGI wavelengths. Expanding to direct imaging missions beyond WFIRST-CGI, we also use evolutionary models across a grid of masses and planet-star separations as inputs to compute spectra of hypothetical objects, exploring when reflected light may contribute to a degree comparable to that of thermal emission from the residual heat of formation.

[22]  arXiv:1911.10609 [pdf, other]
Title: Tension of the $E_G$ statistic and RSD data with Planck/$Λ$CDM and implications for weakening gravity
Comments: 20 pages, 7 Figures. The data and the Mathematica data analysis files may be downloaded from this http URL
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)

The $E_G$ statistic is a powerful probe for detecting deviations from GR by combining weak lensing (WL), real-space clustering and redshift space distortion (RSD) measurements thus probing both the lensing and the growth effective Newton constants ($G_L$ and $G_{eff}$). We construct an up to date compilation of $E_G$ statistic data including both redshift and scale dependence ($E_G(R,z)$). We combine this $E_G$ data compilation with an up to date compilation of $f\sigma_8$ data from RSD observations to identify the current level of tension between the Planck/$\Lambda$CDM standard model based on general relativity and a general model independent redshift evolution parametrization of $G_L$ and $G_{eff}$. Each $f\sigma_8$ datapoint considered has been published separately in the context of independent analyses of distinct galaxy samples. However, there are correlations among the datapoints considered due to overlap of the analyzed galaxy samples. Due to these correlations the derived levels of tension of the best fit parameters with Planck/$\Lambda$CDM are somewhat overestimated but this is the price to pay for maximizing the information encoded in the compilation considered. We find that the level of tension increases from about $3.5\sigma$ for the $f\sigma_8$ data compilation alone to about $6\sigma$ when the $E_G$ data are also included in the analysis. The direction of the tension is the same as implied by the $f\sigma_8$ RSD growth data alone (lower $\Omega_m$ and/or weaker effective Newton constant at low redshifts for both the lensing and the growth effective Newton constants ($G_L$ and $G_{eff}$)). These results further amplify the hints for weakening modified gravity discussed in other recent analyses.

[23]  arXiv:1911.10612 [pdf, ps, other]
Title: Binary star detection in the Open Cluster King 1 field
Authors: Parvej Reja Saleh (1), Debasish Hazarika (1), Ajaz Ahmad Dar (2), Padmakar Singh Parihar (3), Eeshankur Saikia (1) ((1) Department of Applied Sciences - Gauhati University - Guwahati - India, (2) Department of Physics - University of Kashmir - Srinagar - India, (3) Indian Institute of Astrophysics - Bangalore - India)
Comments: 12 pages, 7 figures
Subjects: Astrophysics of Galaxies (astro-ph.GA)

A rarely studied open cluster, King 1 is observed using the 1.3m telescope equipped with 2k x 4k CCD at the Vainu Bappu Observatory, India. We analyse the photometric data obtained from the CCD observations in both B and V bands. Out of 132 detected stars in the open cluster King 1 field, we have identified 4 stellar variables and 2 among them are reported as newly detected binary systems, in this paper. The parallax values from GAIA DR2 suggest that the open cluster King 1 is at the background of these two detected binary systems, falling along the same line of sight, giving rise to different parallax values. The periodogram analysis was carried out using Phase Dispersion Minimization (PDM) and Lomb Scargle (LS) method for all the detected variables. PHOEBE (PHysics Of Eclipsing BinariEs) is extensively used to model various stellar parameters of both the detected binary systems. Based on the modeling results obtained from this work, one of the binary systems is reported for the first time as an Eclipsing Detached (ED) and the other as an Eclipsing Contact (EC) binary of W-type W UMa.

[24]  arXiv:1911.10638 [pdf, other]
Title: The Luminosity Function of Red Supergiants in M31
Comments: ApJ, accepted
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

The mass-loss rates of red supergiant stars (RSGs) are poorly constrained by direct measurements, and yet the subsequent evolution of these stars depends critically on how much mass is lost during the RSG phase. In 2012 the Geneva evolutionary group updated their mass-loss prescription for RSGs with the result that a 20 solar mass star now loses 10x more mass during the RSG phase than in the older models. Thus, higher mass RSGs evolve back through a second yellow supergiant phase rather than exploding as Type II-P supernovae, in accord with recent observations (the so-called "RSG Problem"). Still, even much larger mass-loss rates during the RSG phase cannot be ruled out by direct measurements of their current dust-production rates, as such mass-loss is episodic. Here we test the models by deriving a luminosity function for RSGs in the nearby spiral galaxy M31 which is sensitive to the total mass loss during the RSG phase. We carefully separate RSGs from asymptotic giant branch stars in the color-magnitude diagram following the recent method exploited by Yang and collaborators in their Small Magellanic Cloud studies. Comparing our resulting luminosity function to that predicted by the evolutionary models shows that the new prescription for RSG mass-loss does an excellent job of matching the observations, and we can readily rule out significantly larger values.

[25]  arXiv:1911.10656 [pdf, other]
Title: Detectability of SASI activity in supernova neutrino signals
Comments: Latex, 15 pages, 7 Figures
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We introduce a novel methodology for establishing the presence of Standing Accretion Shock Instabilities (SASI) in the dynamics of a core collapse supernova from the observed neutrino event rate at water- or ice-based neutrino detectors. The methodology uses a likelihood ratio in the frequency domain as a test-statistics; it is also employed to assess the potential to estimate the frequency and the amplitude of the SASI modulations of the neutrino signal. The parameter estimation errors are consistent with the minimum possible errors as evaluated from the inverse of the Fisher information matrix, and close to the theoretical minimum for the SASI amplitude. Using results from a core-collapse simulation of a 15 solar-mass star by Kuroda $\it {et\, al.}$ (2017) as a test bed for the method, we find that SASI can be identified with high confidence for a distance to the supernova of up to $\sim 6$ kpc for IceCube and and up to $\sim 3$ kpc for a 0.4 Mt mass water Cherenkov detector. This methodology will aid the investigation of a future galactic supernova.

[26]  arXiv:1911.10690 [pdf, other]
Title: Tomographic detection of the kinematic Sunyaev-Zel'dovich effect using angular redshift fluctuations
Comments: 20 pages, 14 figures, submitted to MNRAS
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

Determining the large-scale distribution of baryons in the late universe is a long-standing challenge in cosmology. To gain insight into this problem, we present a new approach for extracting the kinematic Sunyaev-Zel'dovich (kSZ) effect from observations, ARF-kSZ tomography. This technique involves the cross-correlation of maps of Angular Redshift Fluctuations (ARF), which contain precise information about the cosmic density and velocity fields, and cosmic microwave background (CMB) temperature maps high-pass filtered using aperture photometry. To produce the first and second, in this work we resort to galaxies and quasars from 6dF and SDSS and foreground-cleaned CMB maps from Planck, respectively. We detect statistically significant cross-correlation between ARF and filtered CMB maps for a wide range of redshifts and filter apertures, yielding a joint detection of the kSZ effect at the $>10\sigma$ level. Using measurements of the kSZ optical depth extracted from these cross-correlations, we then set constraints on the properties of the gas responsible for the kSZ effect, finding that the kSZ gas resides mostly outside haloes and presents densities from 10 to 250 times the cosmic average, which is the density of baryons in filaments and sheets according to cosmological hydrodynamical simulations. Finally, we conduct a tomographic census of baryons from redshift z=0 to 5, finding that ARF-kSZ tomography is sensitive to approximately half of the baryons in the Universe.

[27]  arXiv:1911.10706 [pdf, other]
Title: Accretion History of AGN II: Constraints on AGN Spectral Parameters using the Cosmic X-ray Background
Comments: Accepted by ApJ, 15 pages, 7 figures and 3 tables
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)

We constrain X-ray spectral shapes for the ensemble of AGN based on the shape of the Cosmic X-ray Background (CXB). Specifically, we rule out regions of X-ray spectral parameter space that do not reproduce the CXB in the energy range 1-100 keV. The key X-ray spectral parameters are the photon index, {\Gamma}; the cutoff energy, Ecutoff; and the reflection scaling factor, R. Assuming each parameter follows a Gaussian distribution, we first explore the parameter space using a Bayesian approach and a fixed X-ray luminosity function (XLF). For {\sigma}_E = 36 keV and {\sigma}_R = 0.14, fixed at the observed values from the Swift-BAT 70-month sample, we allow <R>, <Ecutoff > and <{\Gamma}> to vary subject to reproducing the CXB. We report results for {\sigma}_{\Gamma} = 0.1-0.5. In an alternative approach, we define the parameter distributions, then forward model to fit the CXB by perturbing the XLF using a neural network. This approach allows us to rule out parameter combinations that cannot reproduce the CXB for any XLF. The marginalized conditional probabilities for the four free parameters are: <R> = 0.99^{+0.11}_{-0.26}, <Ecutoff> = 118^{+24}_{-23}, {\sigma}_{\Gamma} = 0.101^{+0.097}_{-0.001} and <{\Gamma}> = 1.9^{+0.08}_{-0.09}. We provide an interactive online tool for users to explore any combination of <Ecutoff>, {\sigma}_E, <{\Gamma}>, {\sigma}_{\Gamma}, <R> and {\sigma}_R including different distributions for each absorption bin, subject to the integral CXB constraint. The distributions observed in many AGN samples can be ruled out by our analysis, meaning these samples can not be representative of the full AGN population. The few samples that fall within the acceptable parameter space are hard X-ray-selected, commensurate with their having fewer selection biases.

[28]  arXiv:1911.10721 [pdf, ps, other]
Title: A More Efficient Search for H2O Megamaser Galaxies : The Power of the X-ray and Mid-infrared Photometry
Comments: 20 pages, 11 figures, 4 tables, submitted
Subjects: Astrophysics of Galaxies (astro-ph.GA)

We present a new investigation of the dependence of H2O maser detection rates and properties on the mid-IR AGN luminosity, L_AGN, and the obscuring column density, N_H, based on mid-IR and hard X-ray photometry. Based on spectral energy distribution fitting that allows for decomposition of the black hole accretion and star-formation components in the mid-infrared, we show that the megamaser (disk maser) detection rate increases sharply for galaxies with 12 micron AGN luminosity L^{AGN}_{12 micron} greater than 10^42 erg/s, from ~<3%(~<2%) to ~12%(~5%). By using the ratio of the observed X-ray to mid-IR AGN luminosity as an indicator of N_H, we also find that the megamaser (disk maser) detection rates are boosted to 15%(7%) and 20%(9%) for galaxies with N_H >= 10^23 cm^{-2} and N_H >= 10^{24} cm^{-2}, respectively. Combining these column density cuts with a constraint for high L^{AGN}_{12 micron} (>=10^42 erg/s) predicts further increases in the megamaser (disk maser) detection rates to 19%(8%) and 27%(14%), revealing unprecedented potential boosts of the megamaser and disk maser detection rates by a factor of 7-15 relative to the current rates, depending on the chosen sample selection criteria. A noteworthy aspect of these new predictions is that the completeness rates are only compromised mildly, with the rates remaining at the level of ~95%(~50%) for sources with N_H >= 10^{23} cm^{-2} (N_H >= 10^24 cm^-2). Applying these selection methods to the current X-ray AGN surveys predicts the detection of >~15 new megamaser disks.

[29]  arXiv:1911.10740 [pdf, other]
Title: The FLASHES Survey I: Integral Field Spectroscopy of the CGM around 48 $z=2.3-3.1$ QSOs
Comments: Submitted to ApJ
Subjects: Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)

We present the pilot study component of the Fluorescent Lyman-Alpha Structures in High-z Environments (FLASHES) Survey; the largest integral-field spectroscopy survey to date of the circumgalactic medium at $z=2.3-3.1$. We observed 48 quasar fields between 2015 and 2018 with the Palomar Cosmic Web Imager (Matuszewski et al. 2010). Extended HI Lyman-$\mathrm{\alpha}$ emission is discovered around 42/48 of the observed quasars, ranging in projected, flux-weighted radius from 21-71 proper kiloparsecs (pkpc), with 26 nebulae exceeding $100\mathrm{~pkpc}$ in effective diameter. The circularly averaged surface brightness radial profile peaks at a maximum of $\mathrm{1\times 10^{-17}~erg~s^{-1}~cm^{-2}~arcsec^{-2}}$ ($2\times10^{-15}~\mathrm{erg~s^{-1}~cm^{-2}~arcsec^{-2}}$ adjusted for cosmological dimming) and luminosities range from $1.9\times10^{43}~\mathrm{erg~s^{-1}}$ to $-14.1\times10^{43}~\mathrm{erg~s^{-1}}$. The emission appears to have a highly eccentric morphology and a maximum covering factor of $50\%$ ($60\%$ for giant nebulae). On average, the nebular spectra are red-shifted with respect to both the systemic redshift and Ly$\alpha$ peak of the quasar spectrum. The integrated spectra of the nebulae mostly have single or double-peaked line shapes with global dispersions ranging from $167~\mathrm{km~s^{-1}}$ to $690~\mathrm{km~s^{-1}}$, though the individual (Gaussian) components of lines with complex shapes mostly appear to have dispersions $\leq 400$ $\mathrm{km~s^{-1}}$, and the flux-weighted velocity centroids of the lines vary by thousands of $ \mathrm{km~s^{-1}}$ with respect to the systemic QSO redshifts. Finally, the root-mean-square velocities of the nebulae are found to be consistent with (i.e., not exceeding) gravitational motions expected in host dark matter halos of QSOs at this redshift. We compare these results to existing surveys at both higher and lower redshift.

[30]  arXiv:1911.10756 [pdf, ps, other]
Title: The extended molecular envelope of the asymptotic giant branch star $π^{1}$ Gruis as seen by ALMA II. The spiral-outflow observed at high-angular resolution
Comments: 12 pages, 11 figures
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

The AGB star $\pi^{1}$ Gruis has a known companion (at a separation of ~400 AU) which cannot explain the strong deviations from the spherical symmetry of the CSE. Recently, hydrodynamic simulations of mass transfer in closer binary systems have successfully reproduced the spiral-shaped CSEs found around a handful of sources. There is growing evidence for an even closer, undetected companion complicating the case of $\pi^{1}$ Gruis further. The improved spatial resolution allows for the investigation of the complex circumstellar morphology and the search for imprints on the CSE of the third component. We have observed the 12CO J=3-2 line emission from $\pi^{1}$ Gruis using both the compact and extended array of Atacama Large Millimeter/submillimeter Array (ALMA). The interferometric data has furthermore been combined with data from the ALMA total power (TP) array. The imaged brightness distribution has been used to constrain a non-local, non-LTE 3D radiative transfer model of the CSE. The high-angular resolution ALMA data have revealed the first example of a source on the AGB where both a faster bipolar outflow and a spiral pattern along the orbital plane can be seen in the gas envelope. The spiral can be traced in the low- to intermediate velocity, from 13 to 25 km s$^{-1}$, equatorial torus. The largest spiral-arm separation is $\approx$5".5 and consistent with a companion with an orbital period of $\approx$330 yrs and a separation of less than 70 AU. The kinematics of the bipolar outflow is consistent with it being created during a mass-loss eruption where the mass-loss rate from the system increased by at least a factor of 5 during 10-15 yrs. The spiral pattern is the result of an undetected companion. The bipolar outflow is the result of a rather recent mass-loss eruption event.

[31]  arXiv:1911.10766 [pdf, ps, other]
Title: An Artificial Intelligence based approach for constraining the redshift of blazars using $γ$--ray observation
Comments: 3 Figures, 3 Tables, Accepted for Publication in Experimental Astronomy
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Experiment (hep-ex)

In this paper, we discuss an artificial intelligence based approach to constrain the redshift of blazars using combined $\gamma$--ray observations from the \emph{Fermi} Large Area Telescope (LAT) and ground based atmospheric Cherenkov telescopes (ACTs) in GeV and \emph{sub} TeV energy regimes respectively. The spectral measurements in GeV and TeV energy bands show a redshift dependent spectral break in the $\gamma$--ray spectra of blazars. We use this observational feature of blazars to constrain their redshift. The observed spectral information of blazars with known redshifts reported in the \emph{Fermi} catalogs (3FGL and 1FHL) and TeV catalog are used to train an Artificial Neural Network (ANN) based algorithm. The training of the ANN methodology is optimized using \emph{Levenberg - Marquardt} algorithm with $\gamma$--ray spectral indices and redshifts of 35 well observed blazars as input and output parameters respectively. After training, we use only observed spectral indices in GeV and sub TeV regimes for 10 blazars as inputs to predict their redshifts. The comparison of predicted redshifts by the ANN with the known redshift suggests that both the values are consistent within $\sim$ 18$\%$ uncertainty. The method proposed in the present work would be helpful in future for constraining or predicting the redshifts of the blazars using only observational $\gamma$--ray spectral informations obtained from the \emph{Fermi}-LAT and current generation IACTs as well as from the next generation Cherenkov Telescope Array (CTA) with improved source statistics.

[32]  arXiv:1911.10778 [pdf, other]
Title: Deep learning for Sunyaev-Zel'dovich detection in Planck
Authors: Victor Bonjean
Comments: 11 pages, 11 figures, accepted in A&A
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)

The Planck collaboration has extensively used the six Planck HFI frequency maps to detect the Sunyaev-Zel'dovich (SZ) effect with dedicated methods, e.g., by applying (i) component separation to construct a full sky map of the y parameter or (ii) matched multi-filters to detect galaxy clusters via their hot gas. Although powerful, these methods may still introduce biases in the detection of the sources or in the reconstruction of the SZ signal due to prior knowledge (e.g., the use of the GNFW profile model as a proxy for the shape of galaxy clusters, which is accurate on average but not on individual clusters). In this study, we use deep learning algorithms, more specifically a U-Net architecture network, to detect the SZ signal from the Planck HFI frequency maps. The U-Net shows very good performance, recovering the Planck clusters in a test area. In the full sky, Planck clusters are also recovered, together with more than 18,000 other potential SZ sources, for which we have statistical hints of galaxy cluster signatures by stacking at their positions several full sky maps at different wavelengths (i.e., the CMB lensing map from Planck, maps of galaxy over-densities, and the ROSAT X-ray map). The diffuse SZ emission is also recovered around known large-scale structures such as Shapley, A399-A401, Coma, and Leo. Results shown in this proof-of-concept study are promising for potential future detection of galaxy clusters with low SZ pressure with this kind of approach, and more generally for potential identification and characterisation of large-scale structures of the Universe via their hot gas.

[33]  arXiv:1911.10795 [pdf]
Title: NLTE Analysis of Copper Abundances in the Galactic Bulge Stars
Comments: 9 pages, 6 figures, 3 tables
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

Based on the medium-high resolution (R~ 20,000), modest signal-to-noise ratio (S/N > 70) FLAMES-GIRAFFE spectra, we investigated the copper abundances of 129 red giant branch stars in the Galactic bulge with [Fe/H] from -1.14 to 0.46 dex. The copper abundances are derived from both local thermodynamic equilibrium (LTE) and nonlocal thermodynamic equilibrium (NLTE) with the spectral synthesis method. We find that the NLTE effects for Cu I lines show a clear dependence on metallicity, and they gradually increase with decreasing [Fe/H] for our sample stars. Our results indicate that the NLTE effects of copper are important not only for metal-poor stars but also for supersolar metal-rich ones and the LTE results underestimate the Cu abundances. We note that the [Cu/Fe] trend of the bulge stars is similar to that of the Galactic disk stars spanning the metallicity range of -1.14 < [Fe/H] < 0.0 dex and the [Cu/Fe] ratios increase with increasing metallicity when [Fe/H] is from~-1.2 to~-0.5 dex, favoring a secondary (metallicity-dependent) production of Cu.

[34]  arXiv:1911.10802 [pdf, ps, other]
Title: An extended size-luminosity relation for the reverberation-mapped AGNs: the role of the accretion rate
Authors: Li-Ming Yu, Bi-Xuan Zhao, Wei-Hao Bian, Chan Wang, Xue Ge (School of Physics and Technology, Nanjing Normal University)
Comments: Accepted for publication in MNRAS, 11 pages, 2 tables, 6 figures
Subjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)

For a compiled sample of 120 reverberation-mapped AGNs, the bivariate correlations of the broad-line regions (BLRs) size ($R_{\rm BLR}$) with the continuum luminosity at 5100 \AA\ ($L_{5100}$) and the dimensionless accretion rates ($\dot{\mathscr{M}}$) are investigated. Using our recently calibrated virial factor $f$, and the velocity tracer from the H$\beta$ Full-width at half-maximum (FWHM(H$\beta$)) or the line dispersion ($\sigma_{\rm H\beta}$) measured in the mean spectra, three kinds of SMBH masses and $\dot{\mathscr{M}}$ are calculated. An extended \RL relation including $\dot{\mathscr{M}}$ is found to be stronger than the canonical $R_{\rm BLR}({\rm H\beta}) - L_{\rm 5100}$ relation, showing smaller scatters. The observational parameters, $R_{\rm Fe}$ (the ratio of optical Fe II to H$\beta$ line flux) and the line profile parameter $D_{\rm H\beta}$ ($D_{\rm H\beta}=\rm FWHM(H\beta)/\sigma_{\rm H\beta}$), have relations with three kinds of $\dot{\mathscr{M}}$. Using $R_{\rm Fe}$ and $D_{\rm H\beta}$ to substitute $\dot{\mathscr{M}}$, extended empirical $R_{\rm BLR}({\rm H\beta}) - L_{\rm 5100}$ relations are presented. $R_{\rm Fe}$ is a better "fix" for the $R_{\rm BLR}({\rm H\beta}) - L_{\rm 5100}$ offset than the H$\beta$ shape $D_{\rm H\beta}$. The extended empirical $R_{\rm BLR}({\rm H\beta}) - L_{\rm 5100}$ relation including $R_{\rm Fe}$ can be used to calculate $R_{\rm BLR}$, and thus the single-epoch SMBH mass $M_{\rm BH}$. Our measured accretion rate dependence is not consistent with the simple model of the accretion disk instability leading the BLRs formation. The BLR may instead form from the inner edge of the torus, or from some other means in which BLR size is positively correlated with accretion rate and the SMBH mass.

[35]  arXiv:1911.10817 [pdf, other]
Title: CME-CME Interactions as Sources of CME Geo-effectiveness: The Formation of the Complex Ejecta and Intense Geomagnetic Storm in Early September 2017
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Space Physics (physics.space-ph)

Coronal mass ejections (CMEs) are the primary sources of intense disturbances at Earth, where their geo-effectiveness is largely determined by their dynamic pressure and internal magnetic field, which can be significantly altered during interactions with other CMEs in interplanetary space. We analyse three successive CMEs that erupted from the Sun during September 4-6, 2017, investigating the role of CME-CME interactions as source of the associated intense geomagnetic storm (Dst_min=-142 nT on September 7). To quantify the impact of interactions on the (geo-)effectiveness of individual CMEs, we perform global heliospheric simulations with the EUHFORIA model, using observation-based initial parameters with the additional purpose of validating the predictive capabilities of the model for complex CME events. The simulations show that around 0.45 AU, the shock driven by the September 6 CME started compressing a preceding magnetic ejecta formed by the merging of two CMEs launched on September 4, significantly amplifying its Bz until a maximum factor of 2.8 around 0.9 AU. The following gradual conversion of magnetic energy into kinetic and thermal components reduced the Bz amplification until its almost complete disappearance around 1.8 AU. We conclude that a key factor at the origin of the intense storm triggered by the September 4-6, 2017 CMEs was their arrival at Earth during the phase of maximum Bz amplification. Our analysis highlights how the amplification of the magnetic field of individual CMEs in space-time due to interaction processes can be characterised by a growth, a maximum, and a decay phase, suggesting that the time interval between the CME eruptions and their relative speeds are critical factors in determining the resulting impact of complex CMEs at various heliocentric distances (helio-effectiveness).

[36]  arXiv:1911.10821 [pdf, other]
Title: Astrophysical and local constraints on string theory: runaway dilaton models
Comments: 7 pages, 4 figures; Phys. Rev. D (in press)
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)

One of the clear predictions of string theory is the presence of a dynamical scalar partner of the spin-2 graviton, known as the dilaton. This will violate the Einstein Equivalence Principle, leading to a plethora of possibly observable consequences which is a cosmological context include dynamical dark energy and spacetime variations of nature's fundamental constants. The runaway dilaton scenario of Damour, Piazza and Veneziano is a particularly interesting class of string theory inspired models which can in principle reconcile a massless dilaton with experimental data. Here we use the latest background cosmology observations, astrophysical and laboratory tests of the stability of the fine-structure constant and local tests of the Weak Equivalence Principle to provide updated constraints on this scenario, under various simplifying assumptions. Overall we find consistency with the standard $\Lambda$CDM paradigm, and we improve the existing constraints on the coupling of the dilaton to baryonic matter by a factor of six, and to the dark sector by a factor of two. At the one sigma level the current data already excludes dark sector couplings of order unity, which would be their natural value.

[37]  arXiv:1911.10842 [pdf, ps, other]
Title: Local metallicity distribution function derived from Galactic large-scale radial iron pattern modelling
Comments: 10 pages, 6 figures
Subjects: Astrophysics of Galaxies (astro-ph.GA)

We develop an approach for fitting the results of modeling of wriggling radial large scale iron pattern along the Galactic disk, derived over young (high massive) Cepheids, with the metallicity distribution, obtained using low mass long living dwarf stars in the close solar vicinity. For this, at the step of computing of the theoretical abundance distribution over low mass stars in the solar vicinity we propose to redefine the initial mass function so as the resulting theoretical stellar distribution over masses would be close to the distribution in the observed sample. By means of the above algorithm and subsequent corrections of the theoretical metallicity distribution function, described in literature, we have achieved fairly well agreement of the theoretical and observed metallicity distribution functions for low mass stars in the local solar vicinity.

[38]  arXiv:1911.10853 [pdf, other]
Title: Disks Around T Tauri Stars with SPHERE (DARTTS-S) II: Twenty-one new polarimetric images of young stellar disks
Comments: Accepted for publication by A&A. 14 pages, 7 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

Near-IR polarimetric images of protoplanetary disks provide the ability to characterize sub-structures that are potentially due to the interaction with (forming) planets. The available census is, however, strongly biased toward massive disks around old stars. The DARTTS program aims at alleviating this bias by imaging a large number of T Tauri stars with diverse properties. In this work, we present new SPHERE images of 21 circumstellar disks, which is the largest sample of this time yet to be released. The targets of this work are significantly younger than those published thus far with polarimetric NIR imaging. Scattered light is unambiguously resolved in 11 targets while some polarized unresolved signal is detected in 3 additional sources. Some disk sub-structures are detected. However, the paucity of spirals and shadows from this sample reinforces the trend for which these NIR features are associated with Herbig stars, either because older or more massive. Furthermore, disk rings that are apparent in ALMA observations of some targets do not appear to have corresponding detections with SPHERE. Inner cavities larger than 15 au are also absent from our images despite being expected from the SED. On the other hand, 3 objects show extended filaments at larger scale that are indicative of strong interaction with the surrounding medium. All but one of the undetected disks are best explained by their limited size (approximately 20 au) and the high occurrence of stellar companions in these sources suggest an important role in limiting the disk size. One undetected disk is massive and very large at millimeter wavelengths implying it is self-shadowed in the near-IR. This work paves the way towards a more complete and less biased sample of scattered-light observations, which is required to interpret how disk features evolve throughout the disk lifetime.

[39]  arXiv:1911.10859 [pdf, other]
Title: A Hot Cusp-Shaped Confined Solar Flare
Comments: 10 pages, 5 figures
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

We analyze a confined flare that developed a hot cusp-like structure high in the corona (H ~ 66 Mm). A growing cusp-shaped flare arcade is a typical feature in the standard model of eruptive flares, caused by magnetic reconnection at progressively larger coronal heights. In contrast, we observe a static hot cusp during a confined flare. Despite an initial vertical temperature distribution similar to that in eruptive flares, we observe a distinctly different evolution during the late (decay) phase, in the form of prolonged hot emission. The distinct cusp shape, rooted at locations of non-thermal precursor activity, was likely caused by a magnetic field arcade that kinked near the top. Our observations indicate that the prolonged heating was a result of slow local reconnection and an increased thermal pressure near the kinked apexes due to continuous plasma upflows.

[40]  arXiv:1911.10880 [pdf, other]
Title: Observing the redshifted 21 cm signal around a bright QSO at $z\sim 10$
Comments: 11 pages, 10 figures, apj accepted
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

We use hydrodynamics and radiative transfer simulations to study the 21~cm signal around a bright QSO at $z \sim 10$. Due to its powerful UV and X-ray radiation, the QSO quickly increases the extent of the fully ionized bubble produced by the pre-existing stellar type sources, in addition to partially ionize and heat the surrounding gas. As expected, a longer QSO lifetime, $t_{\rm QSO}$, results in a 21~cm signal in emission located at increasingly larger angular radii, $\theta$, and covering a wider range of $\theta$. Similar features can be obtained with a higher galactic emissivity efficiency, $f_{\rm UV}$, so that determining the origin of a large ionized bubble (i.e. QSO vs stars) is not straightforward. Such degeneracy could be reduced by taking advantage of the finite light traveltime effect, which is expected to affect an HII region produced by a QSO differently from one created by stellar type sources. From an observational point of view, we find that the 21 cm signal around a QSO at various $t_{\rm QSO}$ could be detected by SKA1-low with a high signal-noise ratio (S/N). As a reference, for $t_{\rm QSO} = 10\,\rm Myr$, a S/N $\sim 8$ is expected assuming that no pre-heating of the IGM has taken place due to high-$z$ energetic sources, while it can reach value above 10 in case of pre-heating. Observations of the 21~cm signal from the environment of a high-$z$ bright QSO could then be used to set constraints on its lifetime, as well as to reduce the degeneracy between $f_{\rm UV}$ and $t_{\rm QSO}$.

[41]  arXiv:1911.10915 [pdf, other]
Title: Different types of star-planet interactions
Authors: A. A. Vidotto (Trinity College Dublin)
Comments: 10 pages, to appear in the proceedings of the IAU Symposium 354, Solar and Stellar Magnetic Fields: Origins and Manifestations. Eds: Kosovichev, Strassmeier, Jardine; based on a review talk
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)

Stars and their exoplanets evolve together. Depending on the physical characteristics of these systems, such as age, orbital distance and activity of the host stars, certain types of star-exoplanet interactions can dominate during given phases of the evolution. Identifying observable signatures of such interactions can provide additional avenues for characterising exoplanetary systems. Here, I review some recent works on star-planet interactions and discuss their observability at different wavelengths across the electromagnetic spectrum.

[42]  arXiv:1911.10923 [pdf, ps, other]
Title: Co-spatial velocity and magnetic swirls in the simulated solar photosphere
Comments: 9 pages, 6 figures, accepted for publication in Astronomy & Astrophysics
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

Context. Velocity or intensity swirls have now been shown to be widely present throughout the photosphere and chromosphere. It has been suggested that these events could contribute to the heating of the upper solar atmosphere, via exciting Alfv\'en pulses, which could carry significant amounts of energy. However, the conjectured necessary physical conditions for their excitation, that the magnetic field rotates co-spatially and co-temporally with the velocity field, has not been verified. Aims. We aim to understand whether photospheric velocity swirls exist co-spatially and co-temporally with photospheric magnetic swirls, in order to demonstrate the link between swirls and pulses. Methods. The automated swirl detection algorithm (ASDA) is applied to the photospheric horizontal velocity and vertical magnetic fields obtained from a series of realistic numerical simulations using the RMHD code Bifrost. The spatial relationship between the detected velocity and magnetic swirls is further investigated via a well-defined correlation index (CI) study. Results. On average, there are ~63 short-lived photospheric velocity swirls (with lifetimes mostly less than 20 s, and average radius of ~37 km and rotating speeds of ~2.5 km/s) detected in a field of view (FOV) of 6\times6 Mm^{-2}, implying a total population of velocity swirls of ~1.06\times10^7 in the solar photosphere. More than 80% of the detected velocity swirls are found to be accompanied by local magnetic concentrations in intergranular lanes. On average, ~71% of the detected velocity swirls have been found to co-exist with photospheric magnetic swirls with the same rotating direction. Conclusions. The co-temporal and co-spatial rotation in the photospheric velocity and magnetic fields provide evidence that the conjectured condition for the excitation of Alfv\'en pulses by photospheric swirls is fulfilled.

[43]  arXiv:1911.10941 [pdf, ps, other]
Title: SUBARU Near-Infrared Imaging Polarimetry of Misaligned Disks Around SR24 Hierarchical Triple System
Comments: 14 pages, 5 figures, accepted for publication in AJ
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA)

The SR24 multi-star system hosts both circumprimary and circumsecondary disks, which are strongly misaligned from each other. The circumsecondary disk is circumbinary in nature. Interestingly, both disks are interacting, and they possibly rotate in opposite directions. To investigate the nature of this unique twin disk system, we present 0.''1 resolution near-infrared polarized intensity images of the circumstellar structures around SR24, obtained with HiCIAO mounted on the Subaru 8.2 m telescope. Both the circumprimary disk and the circumsecondary disk are resolved and have elongated features. While the position angle of the major axis and radius of the NIR polarization disk around SR24S are 55$^{\circ}$ and 137 au, respectively, those around SR24N are 110$^{\circ}$ and 34 au, respectively. As an overall morphology, the circumprimary disk around SR24S shows strong asymmetry, whereas the circumsecondary disk around SR24N shows relatively strong symmetry. Our NIR observations confirm the previous claim that the circumprimary and circumsecondary disks are misaligned from each other. Both the circumprimary and circumsecondary disks show similar structures in $^{12}$CO observations in terms of its size and elongation direction. This consistency is because both NIR and $^{12}$CO are tracing surface layers of the flared disks. As the radius of the polarization disk around SR24N is roughly consistent with the size of the outer Roche lobe, it is natural to interpret the polarization disk around SR24N as a circumbinary disk surrounding the SR24Nb-Nc system.

[44]  arXiv:1911.10959 [pdf, ps, other]
Title: Exploring the "$L$--$σ$" relation of HII galaxies and giant extragalactic HII regions acting as standard candles
Comments: 9 pages, 5 figures, 1 table, accepted for publication in ApJ
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

Cosmological applications of HII galaxies (HIIGx) and giant extragalactic HII regions (GEHR) to construct the Hubble diagram at higher redshifts require knowledge of the "$L$--$\sigma$" relation of the standard candles used. In this paper, we study the properties of a large sample of 156 sources (25 high-$z$ HII galaxies, 107 local HII galaxies, and 24 giant extragalactic HII regions) compiled by Terlevich et al.(2015). Using the the cosmological distances reconstructed through two new cosmology-independent methods, we investigate the correlation between the H$\beta$ emission-line luminosity $L$ and ionized-gas velocity dispersion $\sigma$. The method is based on non-parametric reconstruction using the measurements of Hubble parameters from cosmic clocks, as well as the simulated data of gravitational waves from the third-generation gravitational wave detector (the Einstein Telescope, ET), which can be considered as standard sirens. Assuming the emission-line luminosity versus ionized gas velocity dispersion relation, $\log L ($H$\beta) = \alpha \log \sigma($H$\beta)+\kappa$, we find the full sample provides a tight constraint on the correlation parameters. However, similar analysis done on three different sub-samples seems to support the scheme of treating HII galaxies and giant extragalactic HII regions with distinct strategies. Using the corrected "$L$--$\sigma$" relation for the HII observational sample beyond the current reach of Type Ia supernovae, we obtain a value of the matter density parameter, $\Omega_{m}=0.314\pm0.054$ (calibrated with standard clocks) and $\Omega_{m}=0.311\pm0.049$ (calibrated with standard sirens), in the spatially flat $\Lambda$CDM cosmology.

[45]  arXiv:1911.10980 [pdf, other]
Title: Measurement of the Cosmic Microwave Background Polarization Lensing Power Spectrum from Two Years of POLARBEAR Data
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

We present a measurement of the gravitational lensing deflection power spectrum reconstructed with two seasons cosmic microwave background polarization data from the POLARBEAR experiment. Observations were taken at 150 GHz from 2012 to 2014 which survey three patches of sky totaling 30 square degrees. We test the consistency of the lensing spectrum with a Cold Dark Matter (CDM) cosmology and reject the no-lensing hypothesis at a confidence of 10.9 sigma including statistical and systematic uncertainties. We observe a value of A_L = 1.33 +/- 0.32 (statistical) +/- 0.02 (systematic) +/- 0.07 (foreground) using all polarization lensing estimators, which corresponds to a 24% accurate measurement of the lensing amplitude. Compared to the analysis of the first year data, we have improved the breadth of both the suite of null tests and the error terms included in the estimation of systematic contamination.

[46]  arXiv:1911.10984 [pdf, other]
Title: Medium-band photometric reverberation mapping of AGNs at $0.1 < z < 0.8$. Techniques and sample
Comments: 12 pages, 6 figures. Accepted to CAOSP as a Special Issue to 12SCSLSA. arXiv admin note: text overlap with arXiv:1911.04073
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

The most popular method of the broad-line region size estimation in active galactic nuclei (AGN) is the reverberation mapping based on measuring the time delay between the continuum flux and the flux in the emission lines. In our work, we apply the method of photometric reverberation mapping in mid-band filters, adapted for observations on the 1-m Zeiss-1000 telescope of Special Astrophysical Observatory of Russian Academy of Sciences, for the study of AGN with broad lines in the range of redshifts $0.1 < z < 0.8$. This paper provides a sample of 8 objects, describes the technique of observations and data processing for 2 studied objects to demonstrate the stability of the used method.

[47]  arXiv:1911.10997 [pdf, other]
Title: 6.7 GHz CH3OH absorption towards the N3 Galactic Center point-source
Comments: 8 pages, 5 figures, Accepted for publication in ApJ
Subjects: Astrophysics of Galaxies (astro-ph.GA)

We present evidence of 6.7 GHz methanol (CH3OH)~and 4.8 GHz formaldehyde (H2CO) absorption towards the Galactic Center (GC) point-source `N3'. Both absorption features are unresolved and spatially aligned with N3. The 6.7 GHz CH3OH contains a single velocity component (centered at ~10 km/s) while the 4.8 GHz H2CO shows two velocity components (centered at ~-3 and +8 km/s). We find that the velocity of these absorption components are similar to that of emission lines from other molecules (e.g., SiO and H3CN) detected toward this compact-source (-13 to +25 km/s; `N3 cloud'). The detection of these absorption features is a firm indication that some of the molecular gas in the N3 molecular cloud is on the near-side of the continuum source. Analysis of the CH3OH absorption kinematics shows a relatively large velocity dispersion (3.8 km/s) for the size scale of this feature (<0.1'', <0.01 pc at the GC; Ludovici et al. 2016), when compared with other similar size GC clouds in the Larson linewidth-size relationship. Further, this linewidth is closer to velocity dispersion measurements for size scales of 1.3 pc, which is roughly the width of the N3 cloud (25''; 1.0 pc). We argue that this relatively broad linewidth, over a small cross-sectional area, is due to turbulence through the depth of the cloud, where the cloud has a presumed line-of-sight thickness of ~1 pc.

[48]  arXiv:1911.11026 [pdf, other]
Title: ALMA Observations of the Extraordinary Carina Pillars: HH 901/902
Authors: Geovanni Cortes-Rangel (IRyA-UNAM), Luis A. Zapata (IRyA-UNAM), Jesus A. Toala (IRyA-UNAM), Paul T. P. Ho (ASIAA), Satoko Takahashi (Joint ALMA Observatory, NAOJ), Adal Mesa-Delgado (PUCC), Josep M. Masque (Universidad de Guanajuato)
Comments: Accepted to The Astronomical Journal
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

We present Atacama Large Millimeter/Submillimeter Array (ALMA) 1.3 mm continuum and C$^{18}$O(2$-$1), N$_2$D$^{+}$(3$-$2), $^{13}$CS(5$-$4), and $^{12}$CO(2$-$1) line sensitive and high angular resolution ($\sim$0.3$''$) observations of the famous carina pillars and protostellar objects HH 901/902. Our observations reveal for the first time, the bipolar CO outflows and the dusty disks (plus envelopes) that are energizing the extended and irradiated HH objects far from the pillars. We find that the masses of the disks$+$envelopes are about 0.1 M$_\odot$ and of the bipolar outflows are between 10$^{-3}$ - 10$^{-4}$ M$_\odot$, which suggests that they could be low- or maybe intermediate- mass protostars. Moreover, we suggest that these young low-mass stars are likely embedded Class 0/I protostars with high-accretion rates. We also show the kinematics of the gas in the pillars together with their respective gas masses (0.1 -- 0.2 M$_\odot$). We estimate that the pillars will be photo-evaporated in 10$^4$ to 10$^5$ years by the massive and luminous stars located in the Trumpler 14 cluster. Finally, given the short photo-evaporated timescales and that the protostars in these pillars are still very embedded, we suggest that the disks inside of the pillars will be quickly affected by the radiation of the massive stars, forming proplyds, like those observed in Orion.

[49]  arXiv:1911.11029 [pdf, other]
Title: How complex is the cosmic web?
Authors: F.Vazza
Comments: 18 pages, 20 figures. MNRAS accepted, in press
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA); Adaptation and Self-Organizing Systems (nlin.AO)

The growth of large-scale cosmic structure is a beautiful exemplification of how complexity can emerge in our Universe, starting from simple initial conditions and simple physical laws. Using {\enzo} cosmological numerical simulations, I applied tools from Information Theory (namely, "statistical complexity") to quantify the amount of complexity in the simulated cosmic volume, as a function of cosmic epoch and environment. This analysis can quantify how much difficult to predict, at least in a statistical sense, is the evolution of the thermal, kinetic and magnetic energy of the dominant component of ordinary matter in the Universe (the intragalactic medium plasma). The most complex environment in the simulated cosmic web is generally found to be the periphery of large-scale structures (e.g. galaxy clusters and filaments), where the complexity is on average $\sim 10-10^2$ times larger than in more rarefied regions, even if the latter dominate the volume-integrated complexity of the simulated Universe. If the energy evolution of gas in the cosmic web is measured on a $\approx 100 $ $\rm kpc/h$ resolution and over a $\approx 200$ $\rm Myr$ timescale, its total complexity is the range of $\sim 10^{16}-10^{17} \rm ~bits$, with little dependence on the assumed gas physics, cosmology or cosmic variance.

[50]  arXiv:1911.11035 [pdf, other]
Title: Estimating Planetary Mass with Deep Learning
Authors: Elizabeth J. Tasker (ISAS, JAXA), Matthieu Laneuville (ELSI), Nicholas Guttenberg (ELSI)
Comments: 17 page, 15 figures, accepted for publication in AJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)

While thousands of exoplanets have been confirmed, the known properties about individual discoveries remain sparse and depend on detection technique. To utilize more than a small section of the exoplanet dataset, tools need to be developed to estimate missing values based on the known measurements. Here, we demonstrate the use of a neural network that models the density of planets in a space of six properties that is then used to impute a probability distribution for missing values. Our results focus on planetary mass which neither the radial velocity nor transit techniques for planet identification can provide alone. The neural network can impute mass across the four orders of magnitude in the exoplanet archive, and return a distribution of masses for each planet that can inform about trends in the underlying dataset. The average error on this mass estimate from a radial velocity detection is a factor of 1.5 of the observed value, and 2.7 for a transit observation. The mass of Proxima Centauri b found by this method is $1.6^{\rm +0.46}_{\rm -0.36}$ M$_\oplus$, where the upper and lower bounds are derived from the root mean square deviation from the log mass probability distribution. The network can similarly impute the other potentially missing properties, and we use this to predict planet radius for radial velocity measurements, with an average error of a factor 1.4 of the observed value. The ability of neural networks to search for patterns in multidimensional data means that such techniques have the potential to greatly expand the use of the exoplanet catalogue.

[51]  arXiv:1911.11058 [pdf, ps, other]
Title: Mapping the dark matter halo of early-type galaxy NGC 2974 through orbit-based models with combined stellar and cold gas kinematics
Comments: 13 pages, 11 figures, accepted for publication in MNRAS
Subjects: Astrophysics of Galaxies (astro-ph.GA)

We present an orbit-based method of combining stellar and cold gas kinematics to constrain the dark matter profile of early-type galaxies. We apply this method to early-type galaxy NGC 2974, using Pan-STARRS imaging and SAURON stellar kinematics to model the stellar orbits, and introducing HI kinematics from VLA observation as a tracer of the gravitational potential. The introduction of the cold gas kinematics shows a significant effect on the confidence limits of especially the dark halo properties: we exclude more than $95\%$ of models within the $1-\sigma$ confidence level of Schwarzschild modelling with only stellar kinematics, and reduce the relative uncertainty of the dark matter fraction significantly to $10\%$ within $5 R_\mathrm{e}$. Adopting a generalized-NFW dark matter profile, we measure a shallow cuspy inner slope of $0.6^{+0.2}_{-0.3}$ when including the cold gas kinematics in our model. We cannot constrain the inner slope with the stellar kinematics alone.

[52]  arXiv:1911.11084 [pdf, other]
Title: Analytical Three-dimensional Magnetohydrostatic Equilibrium Solutions for Magnetic Field Extrapolation Allowing a Transition from Non-force-free to Force-free Magnetic Fields
Comments: 21 pages, 9 figures, accepted for publication in Solar Physics
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

For the extrapolation of magnetic fields into the solar corona from measurements taken in the photosphere (or chromosphere) force-free magnetic fields are typically used. This does not take into account that the lower layers of the solar atmosphere are not force-free. While some numerical extrapolation methods using magnetohydrostatic magnetic fields have been suggested, a complementary and numerically comparatively cheap method is to use analytical magnetohydrostatic equilibria to extrapolate the magnetic field. In this paper, we present a new family of solutions for a special class of analytical three-dimensional magnetohydrostatic equilibria, which can be of use for such magnetic field extrapolation. The new solutions allow for the more flexible modelling of a transition from non-force-free to (linear) force-free magnetic fields. In particular, the height and width of the region where this transition takes place can be specified by choosing appropriate model parameters.

[53]  arXiv:1911.11131 [pdf, ps, other]
Title: X-ray Emission and Disk Irradiation of HL Tau and HD 100546
Comments: 26 pages, 8 figures
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

We present new X-ray observations of the optically-obscured protostar HL Tau and the intermediate mass Herbig Be star HD 100546. Both objects are surrounded by spectacular disks showing complex morphology including rings and gaps that may have been sculpted by protoplanets. HL Tau was detected as a variable hard X-ray source by Chandra, typical of late-type magnetically-active coronal sources. No extended X-ray emission was seen along the HL Tau jet, or along the jet of the T Tauri binary system XZ Tau located 23 arcsecs to its east. In contrast, HD 100546 was detected by XMM-Newton as a soft X-ray source with no short-term (<1 day) variability. Its X-ray properties are remarkably similar to the Herbig stars AB Aur and HD 163296, strongly suggesting that their X-ray emission arises from the same mechanism and is intrinsic to the Herbig stars themselves, not due to unseen late-type companions. We consider several possible emission mechanisms and conclude that the X-ray properties of HD 100546 are consistent with an accretion shock origin, but higher resolution grating spectra capable of providing information on individual emission lines are needed to more reliably distinguish between accretion shocks and alternatives. We show that X-ray ionization and heating are mainly confined to the upper disk layers in both HL Tau and HD 100546, and any exoplanets near the midplane at distances >1 au are well-shielded from X-rays produced by the central star.

Cross-lists for Tue, 26 Nov 19

[54]  arXiv:1911.10207 (cross-list from hep-th) [pdf, other]
Title: Cosmological Decoherence from Thermal Gravitons
Comments: 30 pages, 6 figures; comments welcome
Subjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); Quantum Physics (quant-ph)

We study the effects of gravitationally-driven decoherence on tunneling processes associated with false vacuum decays, such as the Coleman--De~Luccia instanton. We compute the thermal graviton-induced decoherence rate for a wave function describing a perfect fluid of nonzero energy density in a finite region. When the effective cosmological constant is positive, the thermal graviton background sourced by a de Sitter horizon provides an unavoidable decoherence effect, which may have important consequences for tunneling processes in cosmological history. We discuss generalizations and consequences of this effect and comment on its observability and applications to black hole physics.

[55]  arXiv:1911.10210 (cross-list from hep-ph) [pdf, other]
Title: Exotic Higgs Decays and the Electroweak Phase Transition
Comments: 26 pages, 4 figures. Happy Thanksgiving!
Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Experiment (hep-ex)

Light new physics weakly coupled to the Higgs can induce a strong first-order electroweak phase transition (EWPT). Here, we argue that scenarios in which the EWPT is driven first-order by a light scalar with mass between $\sim 10$ GeV - $m_h/2$ and small mixing with the Higgs will be conclusively probed by the high-luminosity LHC and future Higgs factories. Our arguments are based on analytic and numerical studies of the finite-temperature effective potential and provide a well-motivated target for exotic Higgs decay searches at the LHC and future lepton colliders.

[56]  arXiv:1911.10219 (cross-list from gr-qc) [pdf, other]
Title: Black hole mergers, gravitational waves and scaling relations
Comments: 6 pages, 4 figures
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

Observations of gravitational waves provide new opportunities to study our Universe. In particular, mergers of stellar black holes are the main targets of the current gravitational wave experiments. In order to make accurate predictions, it is however necessary to simulate the mergers in numerical general relativity, which requires high performance computing. Yet numerical simulation codes are optimized for specific mass scales, and may not be adapted to the study of other mass scales. In particular, primordial black holes can have masses ranging from the Planck mass to millions of solar masses, and simulations of primordial black hole mergers over the whole mass range are currently beyond the capabilities of the numerical codes. In this letter, we derive scaling relations, which can be used to rescale simulations of stellar black hole mergers and gravitational waves to any mass scale, hence allowing to perform precise simulations at any mass scale. In addition we study the domain of validity of the rescaling.

[57]  arXiv:1911.10221 (cross-list from hep-ph) [pdf, other]
Title: Optical properties of dynamical axion backgrounds
Comments: Comments are welcome
Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)

We discuss spectral distortions, time delays and refraction of light in an axion or axion-plasma background. This involves solving the full set of geodesic equations associated to the system of Hamiltonian optics, allowing us to self-consistently take into account the evolution of the momentum, frequency and position of photons. We support our arguments with analytic approximations and full numerical solutions. Remarkably, the introduction of a plasma enhances the sensitivity to axion-induced birefringence, allowing these effects to occur at linear order in the axion-photon coupling even when the axion background is not present at either the emission or detection points. This suggests a general enhancement of axion-induced birefringence when the background refractive index is different from one.

[58]  arXiv:1911.10230 (cross-list from physics.space-ph) [pdf]
Title: Angular Scattering in Charge Exchange: Issues and Implications for Secondary Interstellar Hydrogen
Comments: 22 pages, 13 figures, to appear in the Astrophysical Journal
Subjects: Space Physics (physics.space-ph); Solar and Stellar Astrophysics (astro-ph.SR)

Interstellar neutral atoms provide a remote diagnostic of plasma in the outer heliosheath and the very local interstellar medium via charge exchange collisions that convert ions into atoms and vice versa. So far, most studies of interstellar atoms assumed that daughter hydrogen atoms directly inherit the kinetic properties of parent protons. This assumption neglects angular scattering of the interacting particles. However, for low relative velocities, as expected for charge exchanges in the outer heliosheath, this scattering is significant. In this study, we present how the parameters of daughter populations depend on the relative velocity and temperatures of parent populations. For this purpose, we numerically compute collision terms with and without this scattering. We find that the secondary population of interstellar hydrogen atoms, for the parent populations with the relative bulk velocity of 20 km s$^{-1}$ and equal temperatures of 7500 K, has ~2 km s$^{-1}$ higher bulk velocity if the scattering is taken into account. Additionally, temperatures are higher by ~2400 K and ~1200 K in parallel and perpendicular direction to the relative motion of parent populations, respectively. Moreover, a significant departure of secondary atoms from the Maxwell-Boltzmann distribution is expected for high relative velocities of parent populations. This process affects the distribution and density of interstellar atoms in the heliosphere and production of pickup ions. Thus, we show that angular scattering in charge exchange collisions is important to include in analyses of interstellar neutral atoms and pickup ions observed at 1 au and in the outer heliosphere.

[59]  arXiv:1911.10237 (cross-list from physics.data-an) [pdf, other]
Title: Searching for new physics with profile likelihoods: Wilks and beyond
Comments: Submitted to Nature Expert Recommendations
Subjects: Data Analysis, Statistics and Probability (physics.data-an); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph); Applications (stat.AP)

Particle physics experiments use likelihood ratio tests extensively to compare hypotheses and to construct confidence intervals. Often, the null distribution of the likelihood ratio test statistic is approximated by a $\chi^2$ distribution, following a theorem due to Wilks. However, many circumstances relevant to modern experiments can cause this theorem to fail. In this paper, we review how to identify these situations and construct valid inference.

[60]  arXiv:1911.10356 (cross-list from gr-qc) [pdf, other]
Title: Astrometric Effects of Gravitational Wave Backgrounds with non-Luminal Propagation Speeds
Comments: 14 pages, 16 figures, accepted for publication in Physical Review D
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE)

A passing gravitational wave causes a deflection in the apparent astrometric positions of distant stars. The effect of the speed of the gravitational wave on this astrometric shift is discussed. A stochastic background of gravitational waves would result in a pattern of astrometric deflections which are correlated on large angular scales. These correlations are quantified and investigated for backgrounds of gravitational waves with sub- and super-luminal group velocities. The statistical properties of the correlations are depicted in two equivalent and related ways: as correlation curves and as angular power spectra. Sub-(super-)luminal gravitational wave backgrounds have the effect of enhancing (suppressing) the power in low-order angular modes. Analytical representations of the redshift-redshift and redshift-astrometry correlations are also derived. The potential for using this effect for constraining the speed of gravity is discussed.

[61]  arXiv:1911.10445 (cross-list from hep-th) [pdf, other]
Title: Is Trans-Planckian Censorship a Swampland Conjecture?
Comments: 12 pages, 7 figures
Subjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)

During an accelerated expansion of the Universe, quantum fluctuations of sub-Planckian size can be stretched outside the horizon and be regarded effectively classical. Recently, it has been conjectured that such horizon-crossing of trans-Planckian modes never happens inside theories of quantum gravity (the trans-Planckian censorship conjecture, TCC). We point out several conceptual problems of this conjecture, which is in itself formulated as a statement on the restriction of possible scenarios in a theory: by contrast a standard swampland conjecture is a restriction of possible theories in the landscape of the quantum gravity. We emphasize the concept of swampland universality, i.e. that a swampland conjecture constrains any possible scenario in a given effective field theory. In order to illustrate the problems clearly we introduce several versions of the conjecture, where TCC condition is imposed differently to scenarios realizable in a given theory. We point out that these different versions of the conjecture lead to observable differences: a TCC violation in another Universe can exclude a theory, and such reduction of the landscape restricts possible predictions in our Universe. Our analysis raises the question of whether or not the trans-Planckian censorship conjecture can be regarded as a swampland conjecture concerning the existence of UV completion.

[62]  arXiv:1911.10512 (cross-list from nucl-th) [pdf, ps, other]
Title: Influence of strong magnetic field on the structure properties of strange quark stars
Comments: 20 pages, 12 figures, 3 tables, European Physical Journal A (2019) accepted for publication
Subjects: Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics - Theory (hep-th)

We investigate the thermodynamic properties of strange quark matter under the strong magnetic field in the framework of the MIT bag model in two cases of bag constants. We consider two cases of the magnetic field, the uniform magnetic field and the density-dependent magnetic field to calculate the equation of state of strange quark matter. For the case of density-dependent magnetic field, we use a Gaussian equation with two free parameters $\beta$ and $\theta$ and use two different sets of the parameters for the magnetic field changes (a slow and a fast decrease of the magnetic field from the center to the surface). Our results show that the energy conditions based on the limitation of the energy-momentum tensor, are satisfied in the corresponding conditions. We also show that the equation of state of strange quark matter becomes stiffer by increasing the magnetic field. In this paper, we also calculate the structure parameters of a pure strange quark star using the equation of state. We investigate the compactification factor ($2M/R$) and the surface redshift of star in different conditions. The results show that the strange quark star is denser than the neutron star and it is more compact in the presence of the stronger magnetic field. As another result, the compactification factor increases when we use a slow increase of the magnetic field from the surface to the center. Eventually, we compare our results with the observational results for some strange star candidates, and we find that the structure of the strange star candidates is comparable to that of the star in our model.

[63]  arXiv:1911.10584 (cross-list from physics.comp-ph) [pdf, other]
Title: An Arc-Length Approximation For Elliptical Orbits
Comments: (5 pages, 1 figure, 3 tables)
Subjects: Computational Physics (physics.comp-ph); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)

In this paper, we overlay a continuum of analytical relations which essentially serve to compute the arc-length described by a celestial body in an elliptic orbit within a stipulated time interval. The formalism is based upon a two-dimensional heliocentric coordinate frame, where both the coordinates are parameterized as two infinitely differentiable functions in time by using the Lagrange inversion theorem. The parameterization is firstly endorsed to generate a dynamically consistent ephemerides of any celestial object in an elliptic orbit, and thereafter manifested into a numerical integration routine to approximate the arc-lengths delineated within an arbitrary interval of time. As elucidated, the presented formalism can also be orchestrated to quantify the perimeters of elliptic orbits of celestial bodies solely based upon their orbital period and other intrinsic characteristics.

[64]  arXiv:1911.10622 (cross-list from hep-ph) [pdf, other]
Title: Scale-invariant scalar field dark matter through the Higgs portal
Authors: Catarina Cosme
Comments: Talk at the XI Symposium Quantum Theory and Symmetries (QTS-XI) (July 1st to 5th, 2019, CRM, Univ. of Montreal); to appear in the proceedings (CRM Series on Mathematical Physics, Springer, 2020), Eds. Richard MacKenzie, Manu Paranjape, Zora Thomova, Pavel Winternitz, William Witczak-Krempa. This proceedings paper is based on arXiv:1802.09434v2 [hep-ph] and arXiv:1709.09674v2 [hep-ph]
Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

We introduce an oscillating scalar field coupled to the Higgs that can account for all dark matter in the Universe. Due to an underlying scale invariance of this model, the dark scalar only acquires mass after the electroweak phase transition. We discuss the dynamics of this dark matter candidate, showing that it behaves like dark radiation until the Electroweak phase transition and like non-relativistic matter afterwards. In the case of a negative coupling to the Higgs field, the scalar gets a vacuum expectation value after the electroweak phase transition and may decay into photons, although being sufficiently long-lived to account for dark matter. We show that, within this scenario, for a mass of 7 keV, the model can explain the observed galactic and extra-galactic 3.5 keV X-ray line. Nevertheless, it will be very difficult to probe this model in the laboratory in the near future.

[65]  arXiv:1911.10849 (cross-list from nucl-th) [pdf, ps, other]
Title: A new low-density nuclear matter equation of state from an experimental data analysis including in-medium effects
Comments: 5 pages, 3 figures
Subjects: Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)

The modification of the ground state properties of light atomic nuclei in the nuclear and stellar medium is addressed, using chemical equilibrium constants evaluated from a new analysis of the intermediate energy heavy-ion (Xe+Sn) collision data measured by the INDRA collaboration. Three different reactions are considered, mainly differing by the isotopic content of the emission source. The thermodynamic conditions of the data samples are extracted from the measured multiplicities allowing for an in-medium correction, with the single hypothesis that the different nuclear species in a given sample correspond to a unique common value for the density of the expanding source. We show that this new correction, which was not considered in previous analyses of chemical constants from heavy ion collisions, is necessary, since the observables of the analysed systems show strong deviations from the expected results for an ideal gas of clusters. This experimental data set is further compared to a relativistic mean-field model, and seen to be reasonably compatible with a universal correction of the attractive $\sigma$5 pages,-meson coupling.

[66]  arXiv:1911.10935 (cross-list from nucl-th) [pdf, ps, other]
Title: Universal behavior of compact star based upon gravitational binding energy
Comments: 15 pages, 7 figures
Subjects: Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)

Similar to the compactness parameter ($\beta=M/R$), the gravitational binding energy (GBE) is also a characteristic parameter which can reflect the internal structure of a neutron star and thus can be used to expressing the universal relations. Scaling by the stellar mass, this investigation demonstrates a perfect universal relation between the GBE and the moment of inertia, where both of the normal neutron stars and the quark stars satisfy the same universal relation.
Moreover, a fine empirical relation between the GBE and the tidal deformability is proposed, where the difference of the relations can be used to distinguish wether a pulsar is a normal neutron star or a quark star if the stellar mass and the tidal deformability can be observed or estimated rather accurately.
These universal relations provide a potential way to estimate the GBE if the stellar mass and the moment of inertia/the tidal deformability are precisely measured.

Replacements for Tue, 26 Nov 19

[67]  arXiv:1806.11397 (replaced) [pdf, other]
Title: Distances to Accreting X-ray pulsars: impact of the Gaia DR2
Comments: submitted to A&A
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
[68]  arXiv:1810.04360 (replaced) [pdf, other]
Title: Dark Quark Nuggets
Comments: 39+14 pages, 12 figures, updated to match the published version on journal
Journal-ref: Phys. Rev. D 99, 055047 (2019)
Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[69]  arXiv:1902.01340 (replaced) [pdf, other]
Title: Simulating Turbulence-aided Neutrino-driven Core-collapse Supernova Explosions in One Dimension
Comments: 30 pages, 17 figures. Substantially updated following referee report and resubmitted to AAS Journals
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
[70]  arXiv:1902.04029 (replaced) [pdf, other]
Title: Quantifying tensions in cosmological parameters: Interpreting the DES evidence ratio
Comments: 16 pages, 9 figures. v2 & v3: updates post peer-review. v4: typographical correction to the reported errors in the log S column of Table II. v5: typographical correction to equation 26
Journal-ref: Phys. Rev. D 100, 043504 (2019)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Methods for Astrophysics (astro-ph.IM)
[71]  arXiv:1903.02086 (replaced) [pdf, other]
Title: Neutrino self-interaction and MSW effects on the supernova neutrino-process
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
[72]  arXiv:1903.02553 (replaced) [pdf, other]
Title: The Analogous Structure of Accretion Flows in Supermassive and Stellar Mass Black Holes: New Insights from Faded Changing-Look Quasars
Comments: 26 pages, 12 figures, published in ApJ, 883, 76
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
[73]  arXiv:1903.04843 (replaced) [pdf, other]
Title: Probing GHz Gravitational Waves with Graviton-magnon Resonance
Comments: 5 pages, 1 figure, minor changes
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
[74]  arXiv:1903.06682 (replaced) [pdf, other]
Title: Quantifying dimensionality: Bayesian cosmological model complexities
Comments: 14 pages, 9 figures. v2: updates post peer-review. v3: typographical correction to equation 35
Journal-ref: Phys. Rev. D 100, 023512 (2019)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Methods for Astrophysics (astro-ph.IM)
[75]  arXiv:1903.11433 (replaced) [pdf, other]
Title: General Cosmography Model with Spatial Curvature
Comments: 13 pages, 4 figures, major revised, update data and conclusions
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[76]  arXiv:1904.01028 (replaced) [pdf, other]
Title: Satellites of Satellites: The Case for Carina and Fornax
Comments: 7 pages, 3 figures. Accepted for publication in the Monthly Notices of the Royal Astronomical Society
Subjects: Astrophysics of Galaxies (astro-ph.GA)
[77]  arXiv:1904.04142 (replaced) [pdf, ps, other]
Title: The masses and shadows of the black holes Sagittarius A* and M87* in modified gravity (MOG)
Comments: 5 pages, 2 figures
Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics of Galaxies (astro-ph.GA)
[78]  arXiv:1905.01384 (replaced) [pdf, ps, other]
Title: Slip-Back Mapping as a Tracker of Topological Changes in Evolving Magnetic Configurations
Comments: To be submitted to Ap.J
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[79]  arXiv:1905.10950 (replaced) [pdf, other]
Title: Hyperbolic field space and swampland conjecture for DBI scalar
Comments: 20 pages, 4 figures, matches the published version
Journal-ref: JCAP 1909(2019) 072
Subjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
[80]  arXiv:1905.13634 (replaced) [pdf, other]
Title: Chiral effective field theory description of neutrino nucleon-nucleon Bremsstrahlung in supernova matter
Comments: 21 pages, 12 figures
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph); Nuclear Theory (nucl-th)
[81]  arXiv:1906.01917 (replaced) [pdf, ps, other]
Title: Galaxy simulation with the evolution of grain size distribution
Comments: Accepted for publication into MNRAS, 16 pages, 8 figures
Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
[82]  arXiv:1906.02209 (replaced) [pdf, other]
Title: Insights into formation scenarios of massive Early-Type galaxies from spatially resolved stellar population analysis in CALIFA
Authors: Stefano Zibetti (1), Anna R. Gallazzi (1), Michaela Hirschmann (2 and 3), Guido Consolandi (4), Jesús Falcón-Barroso (5 and 6), Glenn van de Ven (7), Mariya Lyubenova (8) ((1) INAF-Osservatorio Astrofisico di Arcetri, (2) Institut d'Astrophysique de Paris, CNRS, Université Pierre & Marie Curie, (3) DARK, Niels Bohr Institute, University of Copenhagen, (4) INAF-Osservatorio Astronomico di Brera, (5) Instituto de Astrofísica de Canarias, (6) Departamento de Astrofísica, Universidad de La Laguna, (7) Department of Astrophysics, University of Vienna, (8) European Southern Observatory)
Comments: Accepted version to appear in MNRAS. Improved discussion with respect to original submission and additional tests included
Subjects: Astrophysics of Galaxies (astro-ph.GA)
[83]  arXiv:1906.06109 (replaced) [pdf, other]
Title: One simulation to have them all: performance of the Bias Assignment Method against N-body simulations
Comments: Accepted for publication at MNRAS
Journal-ref: MNRAS 2019
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[84]  arXiv:1906.07060 (replaced) [src]
Title: The cosmic microwave background spectral modification due to thermal Comptonization in galaxy clusters. Analytical consideration
Comments: The manuscript is withdrawn since an issue is found in the technique used to compute CMB modification; an additional analysis is being made in order to resolve the problem
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE)
[85]  arXiv:1906.08030 (replaced) [pdf, other]
Title: How to avoid X'es around point sources in maximum likelihood CMB maps
Authors: Sigurd K. Naess
Comments: 16 pages, 4 figures, accepted for publication in JCAP
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[86]  arXiv:1906.08784 (replaced) [pdf, other]
Title: Deep-CEE I: Fishing for Galaxy Clusters with Deep Neural Nets
Authors: Matthew C. Chan (Lancaster), John P. Stott (Lancaster)
Comments: Accepted by MNRAS on 2nd October 2019. 18 pages; doi:10.1093/mnras/stz2936
Journal-ref: Monthly Notices of the Royal Astronomical Society. 490 (December 2019) 5770-5787
Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[87]  arXiv:1907.00602 (replaced) [pdf, other]
Title: Instabilities in a self-gravitating granular gas
Comments: 19 pages, 4 figures, to be published in Physics A
Subjects: Statistical Mechanics (cond-mat.stat-mech); Astrophysics of Galaxies (astro-ph.GA)
[88]  arXiv:1907.02975 (replaced) [pdf, other]
Title: Constraints on the growth rate using the observed galaxy power spectrum
Comments: 19 pages, 5 figures, 5 tables. Significant changes, including a correction to the previous claim that redshift binning can be optimised. Version accepted by JCAP
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[89]  arXiv:1907.04192 (replaced) [pdf, other]
Title: Bulk viscosity of baryonic matter with trapped neutrinos
Comments: v2: matches published version, 27 pages, 21 figures, uses RevTex
Journal-ref: Phys. Rev. D 100, 103021, (2019)
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
[90]  arXiv:1907.05893 (replaced) [pdf, other]
Title: $Z'$ Mediated WIMPs: Dead, Dying, or Soon to be Detected?
Comments: v2: Published version. Modified text, no significant changes. v1:46 pages, 17 figures
Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Experiment (hep-ex)
[91]  arXiv:1907.06866 (replaced) [pdf, ps, other]
Title: Probing antigravitational effects through CP violation on the Moon
Comments: arXiv admin note: text overlap with arXiv:gr-qc/9906012 by other authors
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Experiment (hep-ex)
[92]  arXiv:1907.09373 (replaced) [pdf, ps, other]
Title: Energy-conservation constraints on cosmic string loop production and distribution functions
Comments: 11 pages. v2: new appendix on range of beta, clarifications
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
[93]  arXiv:1907.13150 (replaced) [pdf, other]
Title: Identifying Atmospheres on Rocky Exoplanets Through Inferred High Albedo
Comments: Accepted to ApJ. Also see these three companion papers: 1. Koll et al (accepted to ApJ), "Identifying Candidate Atmospheres on Rocky M Dwarf Planets Via Eclipse Photometry", 2. Malik et al (accepted to ApJ), "Analyzing Atmospheric Temperature Profiles and Spectra of M dwarf Rocky Planets", and 3. Koll (accepted to ApJ) "A Scaling Theory for Atmospheric Heat Redistribution on Rocky Exoplanets"
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
[94]  arXiv:1908.00010 (replaced) [pdf, other]
Title: Instability of twisted magnetar magnetospheres
Authors: J. F. Mahlmann (1), T. Akgün (2), J. A. Pons (2), M. A. Aloy (1), P. Cerdá-Durán ((1) Departament d'Astronomia i Astrofísica, Universitat de València, 46100, Burjassot, Spain, (2) Departament de Fisica Aplicada, Universitat d'Alacant, 03690, Alicante, Spain)
Comments: 21 pages, 11 figures of which 11 are in color. 1 animated figure. Accepted by MNRAS
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
[95]  arXiv:1908.00552 (replaced) [pdf, other]
Title: How feedback shapes galaxies: an analytic model
Authors: Jaime Salcido (1, 2), Richard G. Bower (2), Tom Theuns (2) ((1) ARI, Liverpool John Moores University, (2) ICC, Durham University)
Comments: Refereed version accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS). 19 pages, 17 figures
Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[96]  arXiv:1908.01953 (replaced) [pdf, other]
Title: Probing the independence within the dark sector in the fluid approximation
Comments: 33 pages, 11 figures, 1 table; v2: minor changes and additions, conclusions unchanged, accepted for publication in JCAP
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
[97]  arXiv:1908.05143 (replaced) [pdf, other]
Title: Regularities in the spectrum of chaotic p-modes in rapidly rotating stars
Comments: 19 pages, 20 figures, published version
Journal-ref: Astronomy & Astrophysics 631, A140 (2019)
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Chaotic Dynamics (nlin.CD)
[98]  arXiv:1909.01154 (replaced) [pdf, other]
Title: Time-dependent AMS-02 electron-positron fluxes in an extended force-field model
Authors: Marco Kuhlen, Philipp Mertsch (Aachen)
Comments: 5+5 pages, 2+2 figures; example script available at this https URL; Accepted for publication in PRL
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Space Physics (physics.space-ph)
[99]  arXiv:1909.07988 (replaced) [pdf, other]
Title: CLASH-VLT: Enhancement of (O/H) in z=0.35 RXJ 2248-4431 cluster galaxies
Authors: B. I. Ciocan (1), C. Maier (1), B. L. Ziegler (1), M. Verdugo (1) ((1) University of Vienna)
Comments: Accepted for publication in A&A on 22 November 2019
Subjects: Astrophysics of Galaxies (astro-ph.GA)
[100]  arXiv:1909.08791 (replaced) [pdf, other]
Title: Prospects for Life on Temperate Planets Around Brown Dwarfs
Comments: Accepted for publication in The Astrophysical Journal; 13 pages; 9 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
[101]  arXiv:1909.11455 (replaced) [pdf, other]
Title: The Open Universe VOU-Blazars tool
Journal-ref: Astronomy and Computing 2019
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
[102]  arXiv:1909.13504 (replaced) [pdf, other]
Title: Hybrid Numerical Simulations of Pulsar Magnetospheres
Comments: 7 pages, 5 figures, Monthly Notices in press
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
[103]  arXiv:1909.13810 (replaced) [pdf, other]
Title: Constraining the observer angle of the kilonova AT2017gfo associated with GW170817: Implications for the Hubble constant
Comments: 7 pages; 2 Figures, 2 Tables, accepted to ApJ
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
[104]  arXiv:1910.02090 (replaced) [pdf, ps, other]
Title: The Central Star of NGC 2346 as a Clue to Binary Evolution through the Common Envelope Phase
Comments: Accepted in ApJ
Journal-ref: 2019 ApJ 885 84
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
[105]  arXiv:1910.02413 (replaced) [pdf, other]
Title: General relativistic polarized radiative transfer with inverse Compton scatterings
Comments: 9 pages, 4 figures, accepted for publication in MNRAS
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
[106]  arXiv:1910.02416 (replaced) [pdf, other]
Title: Scale-invariance of black hole accretion: modeling emission from a black hole X-ray binary with relativistic accretion flow simulations
Comments: 7 pages, 3 figures, accepted for publication in MNRAS
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
[107]  arXiv:1910.02886 (replaced) [pdf, other]
Title: Measuring relative abundances in the solar corona with optimised linear combinations of spectral lines
Comments: 13 pages, 14 figures
Journal-ref: A&A 632, A20 (2019)
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Instrumentation and Methods for Astrophysics (astro-ph.IM)
[108]  arXiv:1910.03222 (replaced) [pdf]
Title: Carbon Chain Depletion of 2I/Borisov
Comments: 10 pages, 3 figures, in revision at Astrophysical Journal Letters with new data
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
[109]  arXiv:1910.07574 (replaced) [pdf, other]
Title: Searching for scalar dark matter with compact mechanical resonators
Comments: Revised introduction and abstract. Added new section discussing readout
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Phenomenology (hep-ph); Quantum Physics (quant-ph)
[110]  arXiv:1910.08213 (replaced) [pdf, other]
Title: Gravitational wave stochastic background from cosmological particle decay
Authors: Bruce Allen
Comments: 5 pages, 2 figures. Corrected a factor-of-two mistake in the indirect spectrum, and a more serious error in the direct spectrum calculation, which changes the slope of Omega from f-squared to f. Also showed that cosmological expansion and redshift are correctly accounted for in the calculation
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE)
[111]  arXiv:1910.08310 (replaced) [pdf, other]
Title: Constraining the stochastic gravitational wave from string cosmology with current and future high frequency detectors
Comments: Accepted for publication in The Astrophysical Journal. 10 pages, 5 figures
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Methods for Astrophysics (astro-ph.IM)
[112]  arXiv:1910.11893 (replaced) [pdf, other]
Title: Stellar Dynamos with Solar and Anti-solar Differential Rotations: Implications to Magnetic Cycles of Slowly Rotating Stars
Comments: Accepted for publication in MNRAS
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Instrumentation and Methods for Astrophysics (astro-ph.IM)
[113]  arXiv:1911.04716 (replaced) [pdf, other]
Title: The structure in front of the Galactic bar traced by red clump stars in the VVV survey
Comments: 10 pages, 7 figures, V2: results unchanged but some modification to the interpretation
Subjects: Astrophysics of Galaxies (astro-ph.GA)
[114]  arXiv:1911.06337 (replaced) [pdf, other]
Title: Stellar population astrophysics (SPA) with the TNG. Revisiting the metallicity of Praesepe (M44)
Comments: 13 pages, 5 figures. Accepted for publication in A&A
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
[115]  arXiv:1911.06522 (replaced) [pdf, ps, other]
Title: Extensive photometry of the intermediate polar V1033 Cas (IGR J00234+6141)
Comments: 12 pages, 9 figures, accepted for publication in Astrophysics and Space Science
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[116]  arXiv:1911.06579 (replaced) [pdf, other]
Title: Physical Properties of the star-forming clusters in NGC 6334
Comments: Accepted for publication in Astronomy & Astrophysics. 20 pages with 15 figures and 3 tables, plus Appendices with extra figures and tables. (Abstract modified)
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
[117]  arXiv:1911.09116 (replaced) [pdf, other]
Title: Baryonic clues to the puzzling diversity of dwarf galaxy rotation curves
Comments: 16 pages, 14 figures, 1 table. Submitted to MNRAS
Subjects: Astrophysics of Galaxies (astro-ph.GA)
[118]  arXiv:1911.09861 (replaced) [pdf, ps, other]
Title: The chemical signatures of planetary engulfment events in binary systems
Comments: Accepted for publication by ApJL. 11 pages, 6 tables and 1 figure; formatting corrected, removed unused orcID file
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
[119]  arXiv:1911.10078 (replaced) [pdf, other]
Title: Probing a cosmic axion-like particle background within the jets of active galactic nuclei
Comments: This work is prepared for submission to JCAP
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
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