Sazuna/UAT_keywords huggingface dataset:
OO Dra: An Algol-type Binary Formed through an Extremely Helium-poor Mass Accretion Revealed by Asteroseismology. Based on 2 minutes of Transiting Exoplanet Survey Satellite data, we analyzed intrinsic oscillations of the primary component and identified seven confident independent δ Scuti frequencies (f1, f2, f3, f4, f7, f11, and f12). Both single-star evolutionary models and mass-accreting models are computed to reproduce the δ Scuti frequencies and the fitting results match well with each other. The stellar parameters of the primary star yielded by asteroseismology are M = ${1.92}_{-0.02}^{+0.10}$ M⊙, Z = ${0.011}_{-0.001}^{+0.006}$ , R = ${2.068}_{-0.007}^{+0.050}$ R⊙, $\mathrm{log}g$ = ${4.090}_{-0.002}^{+0.010}$ , Teff = ${8346}_{-320}^{+244}$ K, and L = ${18.65}_{-2.82}^{+3.31}$ L⊙, which match well with the dynamic ones using the binary model. Furthermore, our asteroseismic results show that OO Dra is another Algol system that has just undergone the rapid mass-transfer stage. The fitting results of single-star evolutionary models indicate that the pulsator is a helium-poor star with an age of ${8.22}_{-1.33}^{+0.12}$ Myr, and the further mass-accreting models show that the primary star looks like an almost unevolved star formed by an extremely helium-poor mass accretion in the Case A evolutionary scenario.

Keywords: Eclipsing binary stars, Asteroseismology, Delta Scuti variable stars
Dynamical Evolution of an Active-region Filament Driven by Magnetic Reconnection. Studying solar filament dynamical evolutions is an important approach to reveal the driving mechanism of solar eruptions, which seriously impact on the Sun-Earth system and could cause disastrous space weather. To better understand the evolution process of solar filaments, here we investigate an active-region filament by employing observations from the New Vacuum Solar Telescope (NVST), Solar Dynamics Observatory, and Interface Region Imaging Spectrograph. The high-resolution NVST Hα images show that the northern footpoint of the filament gradually moved northward. Near the northern footpoint, there is an arch filament system (AFS). Between adjacent footpoints of the filament and the AFS, transient brightening, underlying magnetic cancellation, and bidirectional flows were detected, which jointly imply that it could be the magnetic reconnection between the filament and the AFS that changes the connection of filament threads and drives its footpoint to move northward. In addition, during the footpoint evolution, the filament with highly twisted structure underwent several untwisting motions. Meanwhile, transient brightenings were also observed and appeared as bright knots around several positions where filament threads might braid with each other. And some bright blobs were also detected to propagate outward from the brightening region. These observations suggest that magnetic reconnection might be responsible for the untwisting motion. This work exposes us to a dynamical scenario of the filament evolution driven by magnetic reconnection, which will promote our understanding of the formation and eruption of the filaments.

Keywords: Solar atmosphere, Solar magnetic reconnection, Solar active region filaments, Solar filament eruptions, Solar magnetic fields
The z   2 [O III] Luminosity Function of Grism-selected Emission-line Galaxies. Upcoming missions such as Euclid and the Nancy Grace Roman Space Telescope (Roman) will use emission-line-selected galaxies to address a variety of questions in cosmology and galaxy evolution in the z &gt; 1 universe. The optimal observing strategy for these programs relies on knowing the number of galaxies that will be found and the bias of the galaxy population. Here we measure the [O III] λ5007 luminosity function for a vetted sample of 1951 mJ+JH+H &lt; 26 galaxies with unambiguous redshifts between 1.90 &lt; z &lt; 2.35, which were selected using Hubble Space Telescope (HST)/WFC3 G141 grism frames made available by the 3D-HST program. These systems are directly analogous to the galaxies that will be identified by the Euclid and Roman missions, which will utilize grism spectroscopy to find [O III] λ5007-emitting galaxies at 0.8 ≲ z ≲ 2.7 and 1.7 ≲ z ≲ 2.8, respectively. We interpret our results in the context of the expected number counts for these upcoming missions. Finally, we combine our dust-corrected [O III] luminosities with rest-frame ultraviolet star formation rates to present a new calibration of the star formation rate density associated with 1.90 &lt; z &lt; 2.35 [O III]-emitting galaxies. We find that these grism-selected galaxies contain roughly half of the total star formation activity at z ~ 2.

Keywords: Observational cosmology, High-redshift galaxies, Galaxy evolution
Effects of Turbulence in the Circumnuclear Disk. A circumnuclear disk (CND) of molecular gas occupies the central few parsecs of the Galactic Center. It is likely subject to turbulent disruptions from violent events in its surrounding environment, but the effect of such perturbations has not yet been investigated in detail. Here we perform 3D, N-body/smoothed particle hydrodynamic simulations with an adapted general turbulence driving method to investigate the CND's structural evolution, in particular its reaction to varied scales of injected turbulence. We find that, because of shear flow in the disk, transient arcs of gas (streams) naturally arise when turbulence is driven on large scales (up to ~4 pc), as might occur when a supernova blast wave encounters the CND. Because energetic events arise naturally and often in the central parsecs of our Galaxy, this result suggests that the transient structures that characterize the CND do not imply that the CND itself is a transient structure. We also note that features similar to the density concentrations, or clumps, detailed in the literature emerge when we account for the observed orientation of the disk and for the spatial resolution of observations. As such, clumps could be an artifact of observational limitations.

Keywords: Galaxy circumnuclear disk, Galactic center, Interstellar medium
The Axisymmetric Streaming Instability Revisited. We examine the accuracy of the terminal velocity approximation and clarify a number of misunderstandings regarding the streaming instability in protoplanetary disks under axisymmetric geometry. In the limit of small Stokes number, St ≪ 1, we derive a prediction for the growth rate of the secular modes, which is accurate to the leading order of St and applies to arbitrary dust-to-gas ratio, $\bar{\epsilon }$ . Unlike the claim by a recent study, we show that the secular modes are always unstable. We clarify that the terminal velocity approximation is compatible with the resonant drag instability in the dust-poor limit, $\bar{\epsilon }\ll 1$ , and the predicted growth rate for the resonant modes by the approximation is analytically derived and numerically tested. We find that the terminal velocity approximation is accurate to the leading order of ${\bar{\epsilon }}^{-1}$ in the dust-rich limit with $\bar{\epsilon }\gg 1$ . However, the approximation is not accurate to the leading order of St and may lead to inaccurate predictions, especially for $\bar{\epsilon }\sim 1$ . We show that, besides dust trapping in local pressure maxima, the only process that causes dust clustering under the terminal velocity approximation, there are additional mechanisms of dust clustering that may contribute to the growth rate. The phase differences between the pressure and density perturbations in both Eulerian and Lagrangian frames are also studied for a better physical understanding of the streaming instability.

Keywords: Planet formation, Planetesimals
Population Synthesis of Black Hole Binaries with Compact Star Companions. We perform a systematic study of merging black hole (BH) binaries with compact star (CS) companions, including black hole-white dwarf (BH-WD), black hole-neutron star (BH-NS), and black hole-black hole (BH-BH) systems. Previous studies have shown that mass transfer stability and common envelope evolution can significantly affect the formation of merging BH-CS binaries through isolated binary evolution. With detailed binary evolution simulations, we obtain easy-to-use criteria for the occurrence of the common envelope phase in mass-transferring BH binaries with a nondegenerate donor, and incorporate the criteria into population synthesis calculations. To explore the impact of a possible mass gap between NSs and BHs on the properties of merging BH-CS binary population, we adopt different supernova mechanisms involving the rapid, delayed, and stochastic prescriptions to deal with the compact remnant masses and the natal kicks. Our calculations show that there are ~105-106 BH-CS binaries in the Milky Way, among which dozens are observable by future space-based gravitational wave detectors. We estimate that the local merger rate density of all BH-CS systems is ~60-200 Gpc-3 yr-1. While there are no low-mass BHs formed via rapid supernovae, both delayed and stochastic prescriptions predict that ~100%/~70%/~30% of merging BH-WD/BH-NS/BH-BH binaries are likely to have BH components within the mass gap.

Keywords: Black holes, Compact binary stars, Gravitational waves, Supernovae, Stellar evolution
Implementation of Monte Carlo Transport in the General Relativistic SpEC Code. Neutrino transport and neutrino-matter interactions are known to play an important role in the evolution of neutron star mergers and of their post-merger remnants. Neutrinos cool remnants, drive post-merger winds, and deposit energy in the low-density polar regions where relativistic jets may eventually form. Neutrinos also modify the composition of the ejected material, impacting the outcome of nucleosynthesis in merger outflows and the properties of the optical/infrared transients that they power (kilonovae). So far, merger simulations have largely relied on approximate treatments of the neutrinos (leakage, moments) that simplify the equations of radiation transport in a way that makes simulations more affordable but also introduces unquantifiable errors in the results. To improve on these methods, we recently published a first simulation of neutron star mergers using a low-cost Monte Carlo algorithm for neutrino radiation transport. Our transport code limits costs in optically thick regions by placing a hard ceiling on the value of the absorption opacity of the fluid, yet all approximations made within the code are designed to vanish in the limit of infinite numerical resolution. We provide here an in-depth description of this algorithm, of its implementation in the SpEC merger code, and of the expected impact of our approximations in optically thick regions. We argue that the last is a subdominant source of error at the accuracy reached by current simulations and for the interactions currently included in our code. We also provide tests of the most important features of this code.

Keywords: Neutron stars, Neutrino astronomy, Computational methods, R-process
H I-to-H<SUB>2</SUB> Transitions in Dust-free Interstellar Gas. We present numerical computations and analysis of atomic-to-molecular (H I-to-H2) transitions in cool (~100 K), low-metallicity, dust-free (primordial) gas in which molecule formation occurs via cosmic-ray-driven negative ion chemistry and removal is by a combination of far-UV photodissociation and cosmic-ray ionization and dissociation. For any gas temperature, the behavior depends on the ratio of the Lyman-Werner (LW) band FUV intensity to gas density, ILW/n, and the ratio of the cosmic-ray ionization rate to the gas density, ζ/n. We present sets of H I-to-H2 abundance profiles for a wide range of ζ/n and ILW/n for dust-free gas. We determine the conditions for which H2 absorption-line self-shielding in optically thick clouds enables a transition from atomic to molecular form for ionization-driven chemistry. We also examine the effects of cosmic-ray energy losses on the atomic and molecular density profiles and transition points. For a unit Galactic interstellar FUV field intensity (ILW = 1) with LW flux 2.07 × 107 photons cm-2 s-1 and a uniform cosmic-ray ionization rate ζ = 10-16 s-1, an H I-to-H2 transition occurs at a total hydrogen gas column density of 4 × 1021 cm-2, within 3 × 107 yr, for a gas volume density of n = 106 cm-3 at 100 K. For these parameters, the dust-free limit is reached for a dust-to-gas ratio ${{\rm{Z}}}_{d}^{{\prime} }\lesssim {10}^{-5}$ , which may be reached for overall metallicities ${Z}^{{\prime} }\lesssim 0.01$ relative to Galactic solar values.

Keywords: Photodissociation regions, Interstellar medium, Cosmic rays
A Sub-2% Distance to M31 from Photometrically Homogeneous Near-infrared Cepheid Period-Luminosity Relations Measured with the Hubble Space Telescope. We present period-luminosity relations (PLRs) for 55 Cepheids in M31 with periods ranging from 4 to 78 days observed with the Hubble Space Telescope using the same three-band photometric system recently used to calibrate their luminosities. Images were taken with the Wide Field Camera 3 in two optical filters (F555W and F814W) and one near-infrared filter (F160W) using the Drift and Shift (DASH) mode of operation to significantly reduce overheads and observe widely separated Cepheids in a single orbit. We include additional F160W epochs for each Cepheid from the Panchromatic Hubble Andromeda Treasury and use light curves from the Panoramic Survey Telescope and Rapid Response System of the Andromeda galaxy project to determine mean magnitudes. Combined with a 1.28% absolute calibration of Cepheid PLRs in the Large Magellanic Cloud from Riess et al. in the same three filters, we find a distance modulus to M31 of μ0 = 24.407 ± 0.032, corresponding to 761 ± 11 kpc and 1.49% uncertainty including all error sources, the most precise determination of its distance to date. We compare our results to past measurements using Cepheids and the tip of the red giant branch. This study also provides the groundwork for turning M31 into a precision anchor galaxy in the cosmic distance ladder to measure the Hubble constant together with efforts to measure a fully geometric distance to M31.

Keywords: Cosmology, Observational astronomy, Optical astronomy, Hubble Space Telescope, Observational cosmology, Cepheid variable stars, Cepheid distance, Galaxies, Near infrared astronomy
The Sonora Brown Dwarf Atmosphere and Evolution Models. I. Model Description and Application to Cloudless Atmospheres in Rainout Chemical Equilibrium. We present a new generation of substellar atmosphere and evolution models, appropriate for application to studies of L-, T-, and Y-type brown dwarfs and self-luminous extrasolar planets. The models describe the expected temperature-pressure profiles and emergent spectra of atmospheres in radiative-convective equilibrium with effective temperatures and gravities within the ranges 200 ≤ T eff ≤ 2400 K and  2.5≤logg≤5.5 . These ranges encompass masses from about 0.5 to 85 Jupiter masses for a set of metallicities ([M/H] = ‑ 0.5 to + 0.5), C/O ratios (from 0.5 to 1.5 times that of solar), and ages. These models expand the diversity of model atmospheres currently available, notably to cooler effective temperatures and greater ranges in C/O. Notable improvements from past such models include updated opacities and atmospheric chemistry. Here we describe our modeling approach and present our initial tranche of models for cloudless, chemical equilibrium atmospheres. We compare the modeled spectra, photometry, and evolution to various data sets.

Keywords: Brown dwarfs, L dwarfs, Y dwarfs, L subdwarfs, T subdwarfs, Stellar atmospheres, T dwarfs
A Catalog of Potential Post-Common Envelope Binaries. We present a catalog containing 839 candidate post-common envelope systems. Common envelope evolution is very important in stellar astrophysics, particularly in the context of very compact and short-period binaries, including cataclysmic variables, as progenitors of, e.g., supernovae Type Ia or mergers of black holes and/or neutron stars. At the same time, it is a barely understood process in binary evolution. Due to limitations, since partially remedied, on direct simulation, early investigations were mainly focused on providing analytic prescriptions of the outcome of common envelope evolution. In recent years, detailed hydrodynamical calculations have produced deeper insight into the previously elusive process of envelope ejection. However, a direct link between the observations and theory of this relatively short-lived phase in binary evolution has not been forthcoming. Therefore, the main insight to be gained from observations has to be derived from the current state of systems likely to have gone through a common envelope. Here we present an extensive catalog of such observations as found in the literature. The aim of this paper is to provide a reliable set of data, obtained from observations, to be used in the theoretical modeling of common envelope evolution. In this catalog, the former common envelope donor star is commonly observed as a white dwarf or hot subdwarf star. This catalog includes period and mass estimates wherever obtainable. Some binaries are borderline cases to allow an investigation of the transition between a common envelope formation and other mass-transfer processes.

Keywords: Subdwarf stars, Close binary stars, White dwarf stars, Spectroscopic binary stars, Stellar masses, Eclipsing binary stars, Cataclysmic variable stars, Common envelope evolution, Catalogs, Common envelope binary stars
Transport of Charged Particles Propagating in Turbulent Magnetic Fields as a Red-noise Process. The transport of charged particles in various astrophysical environments permeated by magnetic fields is described in terms of a diffusion process, which relies on diffusion-tensor parameters generally inferred from Monte Carlo simulations. In this paper, a theoretical derivation of the diffusion coefficient in the case of a purely turbulent magnetic field is presented. The approach is based on a red-noise approximation to model the 2 point correlation function of the magnetic field experienced by the particles between two successive times. This approach is shown to describe the regime in which the Larmor radius of the particles is in resonance with the wavelength power spectrum of the turbulence (gyroresonant regime), extending hence previous results applying to the high-rigidity regime in which the Larmor radius is greater than the larger wavelength of the turbulence. The results are shown to be consistent with those obtained with a Monte Carlo generator. Although not considered in this study, the presence of a mean field on top of the turbulence is discussed.

Keywords: Interplanetary turbulence, Magnetic fields, Cosmic rays
The Spin and Orientation of the Black Hole in XTE J1908+094. NuSTAR observed the black hole candidate XTE J1908+094 during its 2013 and 2019 outbursts. We use relativistic reflection to measure the spin of the black hole through 19 different assumptions of relxill flavors and parameter combinations. The most favored model in terms of the Deviance Information Criterion (DIC) measures the spin of the black hole to be $a={0.55}_{-0.45}^{+0.29}$ , and the inclination to be $\theta ={27}_{-3}^{+2}$ degrees (1σ statistical errors). We look at the effects of coronal geometry assumptions and the density of the accretion disk on the spin prediction. All 19 tested models provide consistent spin estimates. We discuss the evolution of spin measurement techniques using relativistic reflection in X-ray binaries and discuss the implications of this spin measurement in reconciling the distributions of stellar-mass black hole spin measurements made through X-ray and gravitational wave observations.

Keywords: Accretion, Black hole physics, X-ray binary stars, Stellar mass black holes, Low-mass x-ray binary stars
Cosmic Web-halo Connection between Twin Universes. Both simulation and observational data have shown that the spin and shape of dark matter halos are correlated with their nearby large-scale environment. As structure formation on different scales is strongly coupled, it is tricky to disentangle the formation of a halo from that of the large-scale environment, making it difficult to infer which is the driving force behind the correlation between halo spin/shape and the large-scale structure. In this paper, we use N-body simulations to produce twin universes that share the same initial conditions on small scales but that are different on large scales. This is achieved by changing the random seeds for the phase of those k modes smaller than a given scale in the initial conditions. In this way, we are able to disentangle the formation of halo and large-scale structure, making it possible to investigate how halo spin and shape correspond to the change of environment on large scales. We identify matching halo pairs in the twin simulations as those sharing the maximum number of identical particles within them. Using these matched halo pairs, we study the cross match of halo spin and the correlation with the large-scale structure. It is found that when the large-scale environment changes (eigenvector) between the twin simulations, the halo spin has to rotate accordingly, although not significantly, to maintain the universal correlation seen in each simulation. Our results suggest that the large-scale structure is the main factor to drive the correlation between halo properties and their environment.

Keywords: Large-scale structure of the universe, Cold dark matter, Astrostatistics, Computational methods, Galaxy evolution
Far-UV and Optical Emissions from Three Very Large Supernova Remnants Located at Unusually High Galactic Latitudes. Galactic supernova remnants (SNRs) with angular dimensions greater than a few degrees are relatively rare, as are remnants located more than 10° off the Galactic plane. Here we report a UV and optical investigation of two previously suspected SNRs more than 10° in both angular diameter and Galactic latitude. One is a proposed remnant discovered in 2008 through 1420 MHz polarization maps near Galactic coordinates l = 353°, b = -34°. GALEX far-UV (FUV) and Hα emission mosaics show the object's radio emission coincident with an 11° × 14° shell of UV filaments that surrounds a diffuse Hα emission ring. Another proposed high-latitude SNR is the 20° × 26° Antlia nebula (G275.5+18.4) discovered in 2002 through low-resolution all-sky Hα and ROSAT soft X-ray emissions. GALEX FUV and Hα mosaics along with optical spectra indicate the presence of shocks throughout the Antlia nebula with estimated shock velocities of 70 to over 100 km s-1. We also present evidence that it has collided with the NE rim of the Gum Nebula. We find both of these large nebulae are bona fide SNRs with ages less than 105 yr despite their unusually large angular dimensions. We also present FUV and optical images along with optical spectra of a new high-latitude SNR (G249.7+24.7) some 4.5° in diameter which has also been independently discovered in X-rays and radio (Becker at al. 2021). We find this remnant's distance to be ≤400 pc based on the detection of red and blue Na I absorption features in the spectra of two background stars.

Keywords: Supernova remnants