Sazuna/UAT_keywords huggingface dataset:
Simultaneous Estimation of Large-scale Structure and Milky Way Dust Extinction from Galaxy Surveys. The high cosmological precision offered by the next generation of galaxy surveys hinges on improved corrections for Galactic dust extinction. We explore the possibility of estimating both the dust extinction and large-scale structure from a single photometric galaxy survey, making use of the predictable manner in which Milky Way dust affects the measured brightness and colors of galaxies in a given sky location in several redshift bins. To test our method, we use a synthetic catalog from a cosmological simulation designed to model the Vera C. Rubin Observatory Legacy Survey of Space and Time. At high Galactic latitude (∣b∣ ≳ 20°) and a resolution of 1° ( $7^{\prime} $ ), we predict the uncertainty in the measurement of dust extinction, E(B - V), to be 0.005 mag (0.015 mag). This is similar to the uncertainty of existing dust maps, illustrating the feasibility of our method. Simultaneous estimation of large-scale structure is predicted to recover the galaxy overdensity δ with a precision of ~0.01 (~0.05) at 1° ( $7^{\prime} $ ) resolution. We also introduce a Bayesian formalism that combines prior information from existing dust maps with the likelihood of Galactic dust extinction determined from the excursion of observed galaxy properties.

Keywords: Galaxy properties, Astronomical methods, Interstellar dust extinction, Large-scale structure of the universe
Solar Modulation of Galactic Cosmic-Ray Protons Based on a Modified Force-field Approach. In this work, a modified force-field approach is established to investigate the long-term solar modulation of galactic cosmic-ray (GCR) protons. In this approach, the solar modulation potential φ is assumed to be energy dependent. As φ also depends on the local interstellar spectrum (LIS), a new proton LIS model is first presented based on data from Voyager 1 and 2, PAMELA, and AMS-02. Then, a double power-law expression is proposed to model φ as a function of proton energy. By fitting to the selected GCR measurements, the solar cycle variation characteristics of parameters in the expression of φ are obtained, and these parameters are reconstructed using the sunspot number, the heliospheric current sheet tilt angle, and the polarity of heliospheric magnetic field. Finally, a new analytical predictive model for GCR protons is established. It is shown that the 11 and 22 yr cyclic variations of GCRs are reproduced, and the computed proton intensities are in good agreement with GCR measurements at various energies since 1954.

Keywords: Galactic cosmic rays, Solar activity, Heliosphere
The Near-stellar Environment of Class 0 Protostars: A First Look with Near-infrared Spectroscopy. We present near-infrared K-band spectra for a sample of seven Class 0 protostars in the Perseus and Orion star-forming regions. We detect Brγ, CO overtone, and H2 emission, features that probe the near-circumstellar environment of the protostar and reveal evidence of magnetospheric accretion, a hot inner disk atmosphere, and outflows, respectively. Comparing the properties of these features with those of Class I sources from the literature, we find that their Brγ emission and CO emission are generally consistent in strength and velocity width. The Brγ line profiles are broad and centrally peaked, with FWHMs of ∼200 km s‑1 and wings extending to ∼300 km s‑1. The line ratios of our H2 emission features, which are spatially extended for some sources, are consistent with shock excitation and indicate the presence of strong jets or a disk wind. Within our small sample, the frequency of CO band emission (∼67%) is high relative to that of Class I samples (∼15%), indicating that Class 0 sources have high inner disk accretion rates, similar to those of the most actively accreting Class I sources. Collectively, our results suggest that Class 0 sources have similar accretion mechanisms to the more evolved classes, with strong organized stellar magnetic fields established at the earliest observable stage of evolution.

Keywords: Stellar accretion disks, Protostars, Near infrared astronomy
Impact of NICER's Radius Measurement of PSR J0740+6620 on Nuclear Symmetry Energy at Suprasaturation Densities. By directly inverting several neutron star (NS) observables in the three-dimensional parameter space for the equation of state of super-dense neutron-rich nuclear matter, we show that the lower radius limit for PSR J0740+6620 of mass 2.08 ± 0.07 M☉ from Neutron Star Interior Composition Explorer (NICER)'s very recent observation sets a much tighter lower boundary than previously known for nuclear symmetry energy in the density range of (1.0 ~ 3.0) times the saturation density ρ0 of nuclear matter. The super-soft symmetry energy leading to the formation of proton polarons in this density region of NSs is clearly disfavored by the first radius measurement for the most massive NS observed reliably so far.

Keywords: Neutron stars, Nuclear astrophysics
The Impact of Baryonic Physics on the Abundance, Clustering, and Concentration of Halos. We examine the impact of baryonic physics on the halo distribution in hydrodynamic simulations compared to that in dark matter-only (DMO) simulations. We find that, in general, DMO simulations produce halo mass functions (HMFs) that are shifted to higher halo masses than their hydrodynamic counterparts due to the lack of baryonic physics. However, the exact nature of this mass shift is a complex function of mass, halo definition, redshift, and larger-scale environment, and it depends on the specifics of the baryonic physics implemented in the simulation. We present fitting formulae for the corrections one would need to apply to each DMO halo catalog in order to reproduce the HMF found in its hydrodynamic counterpart. Additionally, we explore the dependence on environment of this HMF discrepancy and find that, in most cases, halos in low-density environments are slightly more impacted by baryonic physics than halos in high-density environments. We thus also provide environment-dependent mass correction formulae that can reproduce the conditional, as well as global, HMF. We show that our mass corrections also repair the large-scale clustering of halos, though the environment-dependent corrections are required to achieve an accuracy better than 2%. Finally, we examine the impact of baryonic physics on the halo mass-concentration relation and find that its slope in hydrodynamic simulations is consistent with that in DMO simulations. Ultimately, we recommend that any future work relying on DMO halo catalogs incorporate our mass corrections to test the robustness of their results to baryonic effects.

Keywords: Galaxy dark matter halos, N-body simulations, Hydrodynamical simulations
Three-dimensional Core-collapse Supernova Simulations with 160 Isotopic Species Evolved to Shock Breakout. We present three-dimensional simulations of core-collapse supernovae using the FLASH code that follow the progression of the explosion to the stellar surface, starting from neutrino radiation hydrodynamic simulations of the neutrino-driven phase performed with the CHIMERA code. We consider a 9.6 M⊙ zero-metallicity progenitor starting from both 2D and 3D CHIMERA models and a 10 M⊙ solar-metallicity progenitor starting from a 2D CHIMERA model, all simulated until shock breakout in 3D while tracking 160 nuclear species. The relative velocity difference between the supernova shock and the metal-rich Rayleigh-Taylor (R-T) "bullets" determines how the metal-rich ejecta evolves as it propagates through the density profile of the progenitor and dictates the final morphology of the explosion. We find maximum 56Ni velocities of ~1950 and ~1750 km s-1 at shock breakout from 2D and 3D 9.6 M⊙ CHIMERA models, respectively, due to the bullets' ability to penetrate the He/H shell. When mapping from 2D, we find that the development of higher-velocity structures is suppressed when the 2D CHIMERA model and 3D FLASH model meshes are aligned. The development of faster-growing spherical-bubble structures, as opposed to the slower-growing toroidal structure imposed by axisymmetry, allows for interaction of the bullets with the shock and seeds further R-T instabilities at the He/H interface. We see similar effects in the 10 M⊙ model, which achieves maximum 56Ni velocities of ~2500 km s-1 at shock breakout.

Keywords: Core-collapse supernovae, Hydrodynamics, Massive stars, Supernovae, Stellar evolution
Stringent Tests of Gravity with Highly Relativistic Binary Pulsars in the Era of LISA and SKA. At present, 19 double neutron star (DNS) systems are detected by radio timing and two merging DNS systems are detected by kilohertz gravitational waves. Because of selection effects, none of them has an orbital period Pb in the range of a few tens of minutes. In this paper we consider a multimessenger strategy proposed by Kyutoku et al., jointly using the Laser Interferometer Space Antenna and the Square Kilometre Array to detect and study Galactic pulsar-neutron star (PSR-NS) systems with Pb ~ 10-100 minutes. We assume that we will detect PSR-NS systems by this strategy. We use standard pulsar-timing software to simulate times of arrival of pulse signals from these binary pulsars. We obtain the precision of timing parameters of short-orbital-period PSR-NS systems with orbital period Pb ∈ (8, 120) minutes. We use the simulated uncertainty of the orbital decay, ${\dot{P}}_{b}$ , to predict future tests for a variety of alternative theories of gravity. We show quantitatively that highly relativistic PSR-NS systems will significantly improve the constraint on parameters of specific gravity theories in the strong field regime. We also investigate the orbital periastron advance caused by the Lense-Thirring effect in a PSR-NS system with Pb = 8 minutes, and show that the Lense-Thirring effect will be detectable to a good precision.

Keywords: Pulsar timing method, Gravitation, Non-standard theories of gravity, Pulsars, Binary pulsars
Electron Density Dependence of Extreme Ultraviolet Line Intensity Ratios in Ar XIV. We report the electron density dependence of extreme ultraviolet line intensity ratios in Ar XIV studied using a well-defined electron beam ion trap plasma. The purpose of this study is to examine the potential of the Ar XIV lines in diagnosing the electron density of solar corona active regions with a temperature higher than 3 MK. The experimentally obtained dependence is in good agreement with collisional-radiative model calculations, which ensures the usability of the Ar XIV lines.

Keywords: Solar extreme ultraviolet emission, Atomic data benchmarking
The Influence of Heavy Cosmic Rays in Energy Deposition in Molecular Clouds Employing the GEANT4 Code and Voyager I Data. Galactic and extragalactic cosmic rays fully illuminate and trigger several physical and physicochemical changes in molecular clouds (MCs), including gas and grain heating, molecular destruction and formation, and molecular and atomic desorption (sputtering) from dust/ices to gas phase. Besides the major component in cosmic ray inventory (in flux) being electrons, protons, and alphas, particles with larger atomic numbers have a higher rate of energy delivery (due to richer cosmic ray showers) than the lighter particles, and this may add extra energy input into MCs. To understand this issue, we perform complementary calculations to the previous work on MCs, now adding the heavy ions (12 ≤ Z ≤ 29) in the cosmic ray incoming inventory. Once more, the calculations were performed employing the Monte Carlo toolkit GEANT4 code (considering nuclear and hadron physics). We observe that most projectiles in the heavy ion group have lower deposited energies (roughly 10 times less) than iron with the exception of magnesium (Z = 12) and silicon (Z = 14) which are about double. Cobalt presents the lowest deposited energies with respect to iron (only 0.5%). The total energy deposition in the current model was only roughly 10% higher (outer layers) and virtually the same at the center of the cloud when compared with the previous model (with only protons + alphas + electrons sources). The results show that energy deposition by heavy ions is small compared with the values from light particles, and also suggest a very low temperature enhancement due to heavy ions within the MC, being the protons the dominant agent in the energy delivery and also in the cloud's heating.

Keywords: Cosmic rays
Long-term Spectroscopic Survey of the Pleiades Cluster: The Binary Population. We present the results of a spectroscopic monitoring program of the Pleiades region aimed at completing the census of spectroscopic binaries in the cluster, extending it to longer periods than previously reachable. We gathered 6104 spectra of 377 stars between 1981 and 2021, and merged our radial velocities with 1151 measurements from an independent survey by others started three years earlier. With the combined data spanning more than 43 yr, we have determined orbits for some 30 new binary and multiple systems, more than doubling the number previously known in the Pleiades. The longest period is 36.5 yr. A dozen additional objects display long-term trends in their velocities, implying even longer periods. We examine the collection of orbital elements for cluster members, and find that the shape of the incompleteness-corrected distribution of periods (up to 104 days) is similar to that of solar-type binaries in the field, while that of the eccentricities is different. The mass-ratio distribution is consistent with being flat. The binary frequency in the Pleiades for periods up to 104 days is 25% ± 3% after corrections for undetected binaries, which is nearly double that of the field up to the same period. The total binary frequency including known astrometric binaries is at least 57%. We estimate the internal radial velocity dispersion in the cluster to be 0.48 ± 0.04 km s-1. We revisit the determination of the tidal circularization period, and confirm its value to be 7.2 ± 1.0 days, with an improved precision compared to an earlier estimate.

Keywords: Binary stars, Radial velocity, Spectroscopic binary stars, Spectroscopy, Open star clusters
Distant Relatives: The Chemical Homogeneity of Comoving Pairs Identified in Gaia. Comoving pairs, even at the separations of ${ \mathcal O }({10}^{6})$ au, are a predicted reservoir of conatal stars. We present detailed chemical abundances of 62 stars in 31 comoving pairs with separations of 102-107 au and 3D velocity differences &lt;2 km s-1. This sample includes both bound comoving pairs/wide binaries and unbound comoving pairs. Observations were taken using the Magellan Inamori Kyocera Echelle (MIKE) spectrograph on board the Magellan/Clay Telescope at high resolution (R ~ 45,000) with a typical signal-to-noise ratio of 150 pixel-1. With these spectra, we measure surface abundances for 24 elements, including Li, C, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Nd, and Eu. Taking iron as the representative element, our sample of wide binaries is chemically homogeneous at the level of 0.05 dex, which agrees with prior studies on wide binaries. Importantly, even systems at separations 2 × 105-107 au are homogeneous to 0.09 dex, as opposed to the random pairs, which have a dispersion of 0.23 dex. Assuming a mixture model of the wide binaries and random pairs, we find that 73 ± 22% of the comoving pairs at separations 2 × 105-107 au are conatal. Our results imply that a much larger parameter space of phase space may be used to find conatal stars, to study M-dwarfs, star cluster evolution, exoplanets, chemical tagging, and beyond.

Keywords: Wide binary stars, Late-type stars, Chemical abundances, Stellar kinematics
MCMC-based Voigt Profile Fitting to a Mini-BAL System in the Quasar UM 675. We introduce a Bayesian approach coupled with a Markov Chain Monte Carlo method and the maximum-likelihood statistic for fitting the profiles of narrow absorption lines (NALs) in quasar spectra. This method also incorporates the overlap between different absorbers. We illustrate and test this method by fitting models to a "mini-broad" (mini-BAL) and six NAL profiles in four spectra of the quasar UM 675 taken over a rest-frame interval of 4.24 yr. Our fitting results are consistent with past results for the mini-BAL system in this quasar by Hamann et al. We also measure covering factors (Cf) for two narrow components in the C IV and N V mini-BALs and their overlap covering factor with the broad component. We find that Cf (N V) is always larger than Cf (C IV) for the broad component, while the opposite is true for the narrow components in the mini-BAL system. This could be explained if the broad and narrow components originated in gas at different radial distances, but it seems more likely to be due to being produced by gas at the same distance but with different gas densities (i.e., ionization states). The variability detected only in the broad absorption component in the mini-BAL system is probably due to gas motion, since both Cf (C IV) and Cf (N V) vary. We determine for the first time that multiple absorbing clouds (i.e., a broad and two narrow components) overlap along our line of sight. We conclude that the new method improves fitting results considerably compared to previous methods. * The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. † Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

Keywords: Broad-absorption line quasar, Astronomy data analysis, Quasar absorption line spectroscopy, Quasars
An Eclipsing Black Widow Pulsar in NGC 6712. We report the discovery of the first radio pulsar associated with NGC 6712, an eclipsing black widow (BW) pulsar, J1853-0842A, found by high-sensitivity searches using the Five-hundred-meter Aperture Spherical radio Telescope. This 2.15 ms pulsar is in a 3.56 hr compact circular orbit with a very low mass companion likely of mass 0.018 to 0.036 M⊙ and exhibits eclipsing of the pulsar signal. Though the distance to PSR J1853-0842A predicted from its dispersion measure (155.125 ± 0.004 cm-3 pc) and Galactic free electron density models are about 30% smaller than that of NGC 6712 obtained from interstellar reddening measurements, this is likely due to limited knowledge about the spiral arms and Scutum stellar cloud in this direction. Follow-up timing observations spanning 445 days allow us to localize the pulsar's position to be 0.14 core radii from the center of NGC 6712 and measure a negative spin-down rate for this pulsar of -2.39(2) × 10-21 s s-1. The latter cannot be explained without the acceleration of the globular cluster (GC) and decisively supports the association between PSR J1853-0842A and NGC 6712. Considering the maximum GC acceleration, the Galactic acceleration, and the Shklovskii effect, we place an upper limit on the intrinsic spin-down rate to be 1.11 × 10-20 s s-1. From an analysis of the eclipsing observations, we estimate the electron density of the eclipse region to be about 1.88 × 106 cm-3. We also place an upper limit of the accretion rate from the companion at about 3.05 × 10-13 M⊙ yr-1, which is comparable with some other BWs.

Keywords: Pulsars
Time-dependent Treatment of Cosmic-ray Spectral Steepening Due to Turbulence Driving. Cosmic-ray acceleration at non-relativistic shocks relies on scattering by turbulence that the cosmic rays drive upstream of the shock. We explore the rate of energy transfer from cosmic rays to non-resonant Bell modes and the spectral softening it implies. Accounting for the finite time available for turbulence driving at supernova-remnant shocks yields a smaller spectral impact than found earlier with steady-state considerations. Generally, for diffusion scaling with the Bohm rate by a factor η, the change in spectral index is at most η divided by the Alfvénic Mach number of the thermal sub-shock. For MA ≲ 50 it is well below this limit. Only for very fast shocks and very efficient cosmic-ray acceleration can the change in spectral index reach 0.1. For standard SNR parameters, it is negligible. Independent confirmation is derived by considering the synchrotron energy losses of electrons: if intense nonthermal multi-keV emission is produced, the energy loss, and hence the spectral steepening, is very small for hadronic cosmic rays that produce TeV-band gamma-ray emission.

Keywords: Supernova remnants, Gamma-ray astronomy, Spectral index, Cosmic rays
Magnetic and Rotational Evolution of ρ CrB from Asteroseismology with TESS. During the first half of main-sequence lifetimes, the evolution of rotation and magnetic activity in solar-type stars appears to be strongly coupled. Recent observations suggest that rotation rates evolve much more slowly beyond middle age, while stellar activity continues to decline. We aim to characterize this midlife transition by combining archival stellar activity data from the Mount Wilson Observatory with asteroseismology from the Transiting Exoplanet Survey Satellite (TESS). For two stars on opposite sides of the transition (88 Leo and ρ CrB), we independently assess the mean activity levels and rotation periods previously reported in the literature. For the less active star (ρ CrB), we detect solar-like oscillations from TESS photometry, and we obtain precise stellar properties from asteroseismic modeling. We derive updated X-ray luminosities for both stars to estimate their mass-loss rates, and we use previously published constraints on magnetic morphology to model the evolutionary change in magnetic braking torque. We then attempt to match the observations with rotational evolution models, assuming either standard spin-down or weakened magnetic braking. We conclude that the asteroseismic age of ρ CrB is consistent with the expected evolution of its mean activity level and that weakened braking models can more readily explain its relatively fast rotation rate. Future spectropolarimetric observations across a range of spectral types promise to further characterize the shift in magnetic morphology that apparently drives this midlife transition in solar-type stars.

Keywords: Stellar activity, Stellar winds, Stellar oscillations, Stellar rotation, Stellar evolution
Planetesimals on Eccentric Orbits Erode Rapidly. We investigate the possibility of erosion of planetesimals in a protoplanetary disk. We use theory and direct numerical simulations (lattice Boltzmann method) to calculate the erosion of large-much larger than the mean-free path of gas molecules-bodies of different shapes in flows. We find that erosion follows a universal power law in time, at intermediate times, independent of the Reynolds number of the flow and the initial shape of the body. Consequently, we estimate that planetesimals in eccentric orbits, of even very small eccentricity, rapidly (in about 100 yr) erodes away if the semimajor axis of their orbit lies in the inner disk-less than about 10 au. Even planetesimals in circular orbits erode away in approximately 10,000 yr if the semimajor axis of their orbits are ⪅0.6 au.

Keywords: Protoplanetary disks, Planet formation