Sazuna/UAT_keywords huggingface dataset:
Modeling Evolution of Galactic Bars at Cosmic Dawn. We study the evolution of galactic bars using a suite of very high-resolution zoom-in cosmological simulations of galaxies at z ~ 9-2. Our models were chosen to lie within similar-mass dark matter (DM) halos, log(M vir/M ⊙) ~ 11.65 ± 0.05, at z = 6, 4, and 2, in high- and low-overdensity environments. We apply two galactic wind feedback mechanisms for each model. All galaxies develop subkiloparsec stellar bars differing in their properties. We find that (1) the high-z bars form in response to various perturbations: mergers, close flybys, cold accretion inflows along the cosmological filaments, etc.; (2) these bars account for the large mass fraction of galaxies; (3) bars display large corotation-to-bar size ratios, are weaker compared to their low-redshift counterparts by measuring their Fourier amplitudes, and are very gas-rich; (4) their pattern speed does not exhibit monotonic decline with time owing to braking against DM, as at low z; (5) bar properties, including their stellar population (star formation rates and metal enrichment), depend sensitively on prevailing feedback; and (6) bars can weaken substantially during cosmological evolution, becoming weak oval distortions-hence bars are destroyed and reformed multiple times, unlike their low-z counterparts. In all cases, bars in our simulations have been triggered by interactions. In summary, not only do stellar bars appear to be a contemporary phenomenon, but based on increased frequency of mergers, flybys, and the strength of cold accretion flows at high z, we also expect them to be ubiquitous at redshifts ≳2-the epoch of rapid galaxy growth and larger stellar dispersion velocities.

Keywords: Hydrodynamical simulations, Galaxy interactions, Galaxy evolution, Galactic abundances, Barred spiral galaxies, High-redshift galaxies
Recent Updates to the Gas-phase Chemical Reactions and Molecular Lines in CLOUDY: Their Effects on Millimeter and Submillimeter Molecular Line Predictions. Here, we present our current updates to the gas-phase chemical reaction rates and molecular lines in the spectral synthesis code CLOUDY, and its implications in spectroscopic modeling of various astrophysical environments. We include energy levels, and radiative and collisional rates for HF, CF+, HC3N, ArH+, HCl, HCN, CN, CH, and CH2. Simultaneously, we expand our molecular network involving these molecules. For this purpose, we have added 561 new reactions and have updated the existing 165 molecular reaction rates involving these molecules. As a result, CLOUDY now predicts all the lines arising from these nine molecules. In addition, we also update H2-H2 collisional data up to rotational levels J = 31 for v = 0. We demonstrate spectroscopic simulations of these molecules for a few astrophysical environments. Our existing model for globules in the Crab Nebula successfully predicts the observed column density of ArH+. Our model predicts a detectable amount of HeH+, OH+, and CH+ for the Crab Nebula. We also model the interstellar medium toward HD185418, W31C, and NGC 253, and our predictions match with most of the observed column densities within the observed error bars. Very often molecular lines trace various physical conditions. Hence, this update will be very supportive for spectroscopic modeling of various astrophysical environments, particularly involving submillimeter and mid-infrared observations using the Atacama Large Millimeter/submillimeter Array and the James Webb Space Telescope, respectively.

Keywords: Interstellar molecules, Interstellar abundances, Interstellar clouds
Binary Natal Kicks in the Galactic Center: X-Ray Binaries, Hypervelocity Stars, and Gravitational Waves. Theoretical and observational studies suggest that stellar binaries exist in large numbers in galactic nuclei like our own Galactic Center. Neutron stars (NSs), and debatedly, black holes and white dwarfs, receive natal kicks at birth. In this work, we study the effect of two successive natal kicks on a population of stellar binaries orbiting the massive black hole (MBH) in our Galactic Center. These natal kicks can significantly alter the binary orbit in a variety of ways, and also the orbit of the binary around the MBH. We found a variety of dynamical outcomes resulting from these kicks, including a steeper cusp of single NSs relative to the initial binary distribution. Furthermore, hypervelocity star and binary candidates, including hypervelocity X-ray binaries, are a common outcome of natal kicks. In addition, we show that the population of X-ray binaries in the Galactic Center can be used as a diagnostic for the BH natal kick distribution. Finally, we estimate the rate of gravitational wave events triggered by natal kicks, including binary mergers and EMRIs.

Keywords: Galactic center, X-ray binary stars, Hypervelocity stars, Stellar dynamics, Gravitational waves, Supernova dynamics
Influence of Large-scale Interplanetary Structures on the Propagation of Solar Energetic Particles: The Multispacecraft Event on 2021 October 9. An intense solar energetic particle (SEP) event was observed on 2021 October 9 by multiple spacecraft distributed near the ecliptic plane at heliocentric radial distances R ≲ 1 au and within a narrow range of heliolongitudes. A stream interaction region (SIR), sequentially observed by Parker Solar Probe (PSP) at R = 0.76 au and 48° east from Earth (ϕ = E48°), STEREO-A (at R = 0.96 au, ϕ = E39°), Solar Orbiter (SolO; at R = 0.68 au, ϕ = E15°), BepiColombo (at R = 0.33 au, ϕ = W02°), and near-Earth spacecraft, regulated the observed intensity-time profiles and the anisotropic character of the SEP event. PSP, STEREO-A, and SolO detected strong anisotropies at the onset of the SEP event, which resulted from the fact that PSP and STEREO-A were in the declining-speed region of the solar wind stream responsible for the SIR and from the passage of a steady magnetic field structure by SolO during the onset of the event. By contrast, the intensity-time profiles observed near Earth displayed a delayed onset at proton energies ≳13 MeV and an accumulation of ≲5 MeV protons between the SIR and the shock driven by the parent coronal mass ejection (CME). Even though BepiColombo, STEREO-A, and SolO were nominally connected to the same region of the Sun, the intensity-time profiles at BepiColombo resemble those observed near Earth, with the bulk of low-energy ions also confined between the SIR and the CME-driven shock. This event exemplifies the impact that intervening large-scale interplanetary structures, such as corotating SIRs, have in shaping the properties of SEP events.

Keywords: Solar energetic particles, Solar coronal mass ejection shocks, Corotating streams
Polarimetric Observations of PSR J0614+2229 and PSR J1938+2213 Using FAST. We presented observations of PSRs J0614+2229 and J1938+2213 using the Five-hundred-meter Aperture Spherical radio Telescope. PSR J0614+2229 shows two distinct emission states, in which the emission of state A occurs earlier than that of state B in longitude. The phase offset between the average pulse profile peaks of the two states is about 1.°05. The polarization properties of the average pulse profile of the two states are different with different linear position angle swings. We found that the emission becomes brighter during the transition between the two states, which has never been seen in other mode-changing pulsars before. PSR J1938+2213 appears to consist of a weak emission state superposed by brighter burst emissions. The weak state is always present and the energy of the strongest pulse in the burst state is about 57 times larger than that of the average pulse energy. The polarization properties of the two states are also different, and orthogonal polarization modes can be seen only in the burst state, rather than both states. Our results suggest that, for the two pulsars, the emissions of the two states may be generated in different regions in the pulsar magnetosphere.

Keywords: Radio pulsars, Pulsars
A Simple Condition for Sustained Super-Eddington Black Hole Growth. One of the most pressing questions in cosmology is how the black holes (BHs) powering quasars at high redshift grow to supermassive scales within a billion years of the Big Bang. Here we show that sustained super-Eddington accretion can be achieved for BHs with Eddington fractions f Edd ≳ 2/ϵ, where ϵ is the efficiency with which radiation is generated in the accretion process. In this regime, the radiation carries too little momentum to halt the accretion flow and the infalling gas traps the radiation. The BH growth then proceeds unimpeded until the gas supply is exhausted, in contrast to accretion at lower rates, which is limited by the radiation generated in the accretion process. The large gas supply available in massive high-redshift quasar host galaxies may be readily accreted onto seed BHs via this supply-limited mode of accretion, providing an explanation for how such supermassive BHs are assembled in the early universe. This sustained super-Eddington growth may also explain the short lifetimes inferred for the H II regions surrounding high-redshift quasars, if the bulk of the BH growth occurs without the associated radiation escaping to ionize the intergalactic medium. It furthermore implies that a population of obscured rapidly growing BHs may be difficult to detect, perhaps explaining why so few quasars with Eddington fractions higher than a few have been observed. Finally, this simple condition for sustained super-Eddington growth can easily be implemented in cosmological simulations that can be used to assess in which environments it occurs.

Keywords: Accretion, Black holes, Quasars
StrayCats. II. An Updated Catalog of NuSTAR Stray Light Observations. We present an updated catalog of StrayCats (a catalog of NuSTAR stray light observations of X-ray sources) that includes nearly 18 additional months of observations. StrayCats v2 has an added 53 sequence IDs, 106 rows, and three new identified stray light (SL) sources in comparison to the original catalog. The total catalog now has 489 unique sequence IDs, 862 entries, and 83 confirmed StrayCats sources. Additionally, we provide new resources for the community to gauge the utility and spectral state of the source in a given observation. We have created long-term light curves for each identified SL source using MAXI and Swift/BAT data when available. Further, source extraction regions for 632 identified SL observations were created and are available to the public. In this paper we present an overview of the updated catalog and new resources for each identified StrayCats SL source.

Keywords: Neutron stars, High mass x-ray binary stars, X-ray surveys, Low-mass x-ray binary stars, Astrophysical black holes
A Rapidly Fading Star as a Type II Obscuring Intermediate Luminosity Optical Transient (ILOT) in a Triple-star System. We propose a triple-star scenario where the merger of two pre-main-sequence low-mass stars, ≲0.5 M ⊙, ejects a dusty equatorial outflow that obscures and temporarily causes the disappearance of a massive star, ≳8 M ⊙. The merger of the low-mass inner binary powers a faint outburst, i.e., a faint intermediate luminosity optical transient (ILOT), but its main effect that can last for decades is to (almost) disappear the luminous massive star of the triple system. The typical orbital period of the triple system is about 1 yr. The merger process proceeds as the more-massive star of the two low-mass pre-main-sequence stars starts to transfer mass to the least-massive star in the triple system and as a result of that expands. This type II obscuring ILOT scenario in a triple-star system might account for the fading, rebrightening, and then refading of the massive post-main-sequence star M101-OC1. It might recover in about 20-100 yr. Our study strengthens the claim that there are alternative scenarios to account for the (almost) disappearing of massive stars, removing the need for failed supernovae. In these scenarios the disappearing is temporary, lasting from months to decades, and therefore at a later time the massive star explodes as a core collapse supernova, even if it forms a black hole.

Keywords: Close binary stars, Trinary stars, Transient sources, Variable stars
Exact Analytical Solutions in Inhomogeneous Magnetic Fields for Linear Asteroseismic Waves. We solve for waves in an isothermal, stratified medium with a magnetic field that points along a direction perpendicular to that of gravity and varies exponentially in the direction of gravity. We find exact analytical solutions for two different cases: (a) waves propagating along the direction of the magnetic field and (b) waves propagating along the direction of the gravity. In each case, we find solutions in terms of either the hypergeometric functions or their confluent cousins. We solve the resultant transcendental dispersion relation numerically. The eigenfrequencies decrease with increasing degree of the spatial inhomogeneity of the magnetic field. Further, the nodes of the eigenfunctions leak toward regions of lower Alfvén wave speed due to softened wave-reflection in such regions. Such changes in the dispersion relation and the mode structures may allow the detection of magnetic fields buried in the stellar interior.

Keywords: Magnetohydrodynamics, Stellar pulsations, Helioseismology, Analytical mathematics, Solar physics, Solar magnetic fields, Asteroseismology, Magnetic fields
X-Ray Observations of the Isolated Black Hole Candidate OGLE-2011-BLG-0462 and Other Collapsed Objects Discovered through Gravitational Microlensing. Isolated black holes and neutron stars can be revealed through the observation of long-duration gravitational microlensing events. A few candidates have been found in surveys of stars in the direction of the Galactic bulge. Recently, thanks to the addition of astrometric information at milliarcsecond level, it has been possible to reduce the uncertainties in the masses and distances for some of these "dark" gravitational lenses and select the most promising candidates. These isolated compact objects might emit X-rays powered by accretion from the interstellar medium. Using data of the Chandra, XMM-Newton, and INTEGRAL satellites, we searched for X-ray emission in the isolated black hole candidate OGLE-2011-BLG-0462, and in several other putative collapsed objects found with gravitational microlensing. OGLE-2011-BLG-0462 has been recently interpreted as a 7.1 M ☉ black hole at a distance of 1.6 kpc, although a different group obtained a mass range (1.6-4.4 M ☉) that cannot exclude a massive neutron star. We have derived upper limits on the flux from OGLE-2011-BLG-0462 of 9 × 10-15 erg cm-2 s-1 in the 0.5-7 keV range and ~2 × 10-12 erg cm-2 s-1 in the 17-60 keV range. The implied X-ray luminosity is consistent with the small radiative efficiency expected for a black hole and disfavors a neutron star interpretation. Limits down to a factor of about five lower are obtained for the soft X-ray flux of other candidates, but their interpretation is affected by larger uncertainties in the masses, distances, and spatial velocities.

Keywords: Bondi accretion, Gravitational lensing, Stellar mass black holes, X-ray sources
The Effects of Cosmic Rays on the Chemistry of Dense Cores. Cosmic rays are crucial to the chemistry of molecular clouds and their evolution. They provide essential ionizations, dissociations, heating, and energy to the cold, dense cores. As cosmic rays pierce through clouds they are attenuated and lose energy, which leads to a dependency on the column density of a system. The detailed effects these particles have on the central regions still need to be fully understood. Here, we revisit how cosmic rays are treated in the UCLCHEM chemical modeling code by including both ionization rate and H2 dissociation rate dependencies alongside the production of cosmic ray induced excited species and we study in detail the effects of these treatments on the chemistry of pre-stellar cores. We find that these treatments can have significant effects on chemical abundances, up to several orders of magnitude, depending on the physical conditions. The ionization dependency is the most significant treatment influencing chemical abundances through the increased presence of ionized species, grain desorptions, and enhanced chemical reactions. Comparisons to chemical abundances derived from observations show the new treatments reproduce these observations better than the standard handling. It is clear that more advanced treatments of cosmic rays are essential to chemical models and that including this type of dependency provides more accurate chemical representations.

Keywords: Cosmic rays, Chemical abundances, Astrochemistry
ALMA Reveals Extended Cool Gas and Hot Ionized Outflows in a Typical Star-forming Galaxy at Z = 7.13. We present spatially resolved morphological properties of [C II] 158 μm, [O III] 88 μm, dust, and rest-frame ultraviolet (UV) continuum emission for A1689-zD1, a strongly lensed, sub-L* galaxy at z = 7.13, by utilizing deep Atacama Large Millimeter/submillimeter Array (ALMA) and Hubble Space Telescope (HST) observations. While the [O III] line and UV continuum are compact, the [C II] line is extended up to a radius of r ~ 12 kpc. Using multi-band rest-frame far-infrared continuum data ranging from 52 to 400 μm, we find an average dust temperature and emissivity index of ${T}_{\mathrm{dust}}={41}_{-14}^{+17}$ K and $\beta ={1.7}_{-0.7}^{+1.1}$ , respectively, across the galaxy. We find slight differences in the dust continuum profiles at different wavelengths, which may indicate that the dust temperature decreases with distance. We map the star formation rate (SFR) via IR and UV luminosities and determine a total SFR of 37 ± 1M ☉yr-1 with an obscured fraction of 87%. While the [O III] line is a good tracer of the SFR, the [C II] line shows deviation from the local L [C II]-SFR relations in the outskirts of the galaxy. Finally, we observe a clear difference in the line profile between [C II] and [O III], with significant residuals (~5σ) in the [O III] line spectrum after subtracting a single Gaussian model. This suggests a possible origin of the extended [C II] structure from the cooling of hot ionized outflows. The extended [C II] and high-velocity [O III] emission may both contribute in part to the high L [O III]/L [C II] ratios recently reported in z &gt; 6 galaxies.

Keywords: Galaxy formation, Galaxy evolution, Interstellar medium, Circumgalactic medium, High-redshift galaxies
The Fundamental Plane Relation for Gamma-Ray Pulsars Implied by 4FGL. We explore the validity of the recently reported fundamental plane (FP) relation of γ-ray pulsars using 190 pulsars included in the latest 4FGL-DR3 catalog. This sample number is more than twice as large as that of the original study. The FP relation incorporates four parameters, i.e., the spin-down power, $\dot{{ \mathcal E }}$ , the surface magnetic field, B ⋆, the total γ-ray luminosity, L  γ , and a spectral cutoff energy, ϵ cut. The derivation of ϵ cut is the most intriguing one because ϵ cut depends on the proper interpretation of the available phase-averaged spectra. We construct synthetic phase-averaged spectra, guided by the few existing phase-resolved ones, to find that the best-fit cutoff energy, ϵ c1, corresponding to a purely exponential cutoff (plus a power-law) spectral form, is the parameter that optimally probes the maximum cutoff energy of the emission that originates from the core of the dissipative region, i.e., the equatorial current sheet. Computing this parameter for the 190 4FGL pulsars, we find that the resulting FP relation, i.e., the γ-ray luminosity in terms of the other observables, reads as ${L}_{\gamma }={10}^{14.3\pm 1.3}{({\epsilon }_{{\rm{c}}1}/\mathrm{MeV})}^{1.39\pm 0.17}$ ${({B}_{\star }/{\rm{G}})}^{0.12\pm 0.03}{(\dot{{ \mathcal E }}/\mathrm{erg}\,{{\rm{s}}}^{-1})}^{0.39\pm 0.05}\,\mathrm{erg}\,{{\rm{s}}}^{-1};$ this is in good agreement with both the empirical relation reported by Kalapotharakos et al. and the theoretically predicted relation for curvature radiation. Finally, we revisit the radiation reaction limited condition, to find it is a sufficient but not necessary condition for the theoretical derivation of the FP relation. However, the assumption of the radiation reaction limited acceleration reveals the underlying accelerating electric field component and its scaling with $\dot{{ \mathcal E }}$ .

Keywords: Gamma-ray telescopes, Gamma-rays, Pulsars
The Black Hole Mass Function across Cosmic Time. II. Heavy Seeds and (Super)Massive Black Holes. This is the second paper in a series aimed at modeling the black hole (BH) mass function from the stellar to the (super)massive regime. In the present work, we focus on (super)massive BHs and provide an ab initio computation of their mass function across cosmic time. We consider two main mechanisms to grow the central BH that are expected to cooperate in the high-redshift star-forming progenitors of local massive galaxies. The first is the gaseous dynamical friction process, which can cause the migration toward the nuclear regions of stellar mass BHs originated during the intense bursts of star formation in the gas-rich host progenitor galaxy and the buildup of a central heavy BH seed, M • ~ 103-5 M ⊙, within short timescales of ≲some 107 yr. The second mechanism is the standard Eddington-type gas disk accretion onto the heavy BH seed through which the central BH can become (super)massive, M • ~ 106-10 M ⊙, within the typical star formation duration, ≲1 Gyr, of the host. We validate our semiempirical approach by reproducing the observed redshift-dependent bolometric AGN luminosity functions and Eddington ratio distributions and the relationship between the star formation and the bolometric luminosity of the accreting central BH. We then derive the relic (super)massive BH mass function at different redshifts via a generalized continuity equation approach and compare it with present observational estimates. Finally, we reconstruct the overall BH mass function from the stellar to the (super)massive regime over more than 10 orders of magnitudes in BH mass.

Keywords: Supermassive black holes, Galaxy formation
Connecting the Light Curves of Type IIP Supernovae to the Properties of Their Progenitors. Observations of core-collapse supernovae (CCSNe) reveal a wealth of information about the dynamics of the supernova ejecta and its composition but very little direct information about the progenitor. Constraining properties of the progenitor and the explosion requires coupling the observations with a theoretical model of the explosion. Here we begin with the CCSN simulations of Couch et al., which use a nonparametric treatment of the neutrino transport while also accounting for turbulence and convection. In this work we use the SuperNova Explosion Code to evolve the CCSN hydrodynamics to later times and compute bolometric light curves. Focusing on Type IIP SNe (SNe IIP), we then (1) directly compare the theoretical STIR explosions to observations and (2) assess how properties of the progenitor's core can be estimated from optical photometry in the plateau phase alone. First, the distribution of plateau luminosities (L 50) and ejecta velocities achieved by our simulations is similar to the observed distributions. Second, we fit our models to the light curves and velocity evolution of some well-observed SNe. Third, we recover well-known correlations, as well as the difficulty of connecting any one SN property to zero-age main-sequence mass. Finally, we show that there is a usable, linear correlation between iron core mass and L 50 such that optical photometry alone of SNe IIP can give us insights into the cores of massive stars. Illustrating this by application to a few SNe, we find iron core masses of 1.3-1.5 M ⊙ with typical errors of 0.05 M ⊙. Data are publicly available online on Zenodo: doi:10.5281/zenodo.6631964.

Keywords: Hydrodynamical simulations, Supernova neutrinos, Core-collapse supernovae, Type II supernovae, Computational methods, Radiative transfer, Supernova dynamics