Sazuna/UAT_keywords huggingface dataset:
H I Kinematics and the E(B ‑ V)/N(H I) Ratio. The λ21 cm H I emission that is used to trace the gas-to-dust ratio at high Galactic latitudes has contributions from material beyond the Milky Way disk, with uncertain and likely subsolar metallicity and dust content. These contributions can be isolated kinematically and their presence is clear for sightlines with small mean reddening &lt;E(B ‑ V)&gt; ≲ 0.03 mag, which have mean ratios &lt;N(H I)&gt;/&lt;E(B ‑ V)&gt; that are 20%–50% above the high-latitude Galactic average &lt;N(H I)&gt;/&lt;E(B ‑ V)&gt; = 8.3 × 1021 cm‑2 mag‑1. By mapping N(H I) and E(B ‑ V) across H I high-velocity cloud complexes and the Magellanic Clouds, we show that the reddening of this kinematically isolated gas is on average 5 times smaller per H I than the high-latitude average. However, the aggregate contribution of this gas is small and &lt;N(H I)&gt;/&lt;E(B ‑ V)&gt; = 8.3 × 1021 cm‑2 mag‑1 is the appropriate value for Galactic gas seen at high latitude using the H I and reddening measures employed here and in our previous work.

Keywords: Interstellar line absorption, Interstellar extinction, Interstellar atomic gas, Diffuse interstellar clouds
Exploring the Small-scale Magnetic Fields in the Atmosphere of HD 49385 by Asteroseismic Analysis. Recent asteroseismic studies have shown convincing evidence that magnetic fields may exist in the interior of some pulsating red giants. Inspired by this breakthrough, we explored the effect of small-scale magnetic fields on the p-mode oscillations in an evolved star, HD 49385. We incorporate a modified Eddington T–τ equation that phenomenologically mimics the effect of the magnetic fields in the atmosphere of HD 49385, and calculate the frequencies of p-modes with l = 0, 1, and 2. By comparing the calculated frequencies with the observed ones, we select two best-fit models with either GS98 or A09 chemical composition. Our best-fit models not only fit satisfactorily the observed frequencies but also well reproduce some spectroscopically observed stellar parameters such as effective temperature and log g. Based on the two best-fit models, we have estimated that the small-scale magnetic fields possess a strength of approximately 80 G and spread concentratively at approximately a height of 1850 km in the atmosphere. By selecting the best-fit models with a special requirement on the avoided-crossing mode, we have confirmed that the frequency of the avoided-crossing mode is tightly related to the helium core of the star, and determined the size of the helium core as 0.117 M ⊙ in mass and 0.078 R ⊙ in radius. Based on the improvements of the previous two sides, we can accurately determine the mass of HD 49385 to be 1.25 ± 0.02 M ⊙ with an age of 4.1 Gyr for GS98 composition and 4.5 Gyr for A09 composition.

Keywords: Magnetohydrodynamics, Pulsating variable stars, Stellar cores, Stellar magnetic fields, Asteroseismology, Stellar atmospheres, Stellar evolution
General Relativistic Radiation Magnetohydrodynamics Simulations of Precessing Tilted Super-Eddington Disks. We perform a three-dimensional general relativistic radiation magnetohydrodynamics simulation of a tilted super-Eddington accretion disk around a spinning black hole (BH). The disk, which tilts and twists as it approaches the BH, precesses while maintaining its shape. The gas is mainly ejected around the rotation axis of the outer part of the disk rather than around the spin axis of the BH. The disk precession changes the ejection direction of the gas with time. The radiation energy is also released in approximately the same direction as the outflow, so the precession is expected to cause a quasiperiodic time variation of the observed luminosity. The timescale of the precession is about 10 s for a 10 M ⊙ BH and for the radial extent of a disk of several tens of gravitational radii, where M ⊙ is the solar mass. This timescale is consistent with the frequency of the low-frequency quasiperiodic oscillation (0.01–1 Hz) observed in some ultraluminous X-ray sources.

Keywords: Accretion, Radiative magnetohydrodynamics, Black holes, General relativity
A Kinetic-magnetohydrodynamic Model with Adaptive Mesh Refinement for Modeling Heliosphere Neutral-plasma Interaction. The charge exchange between the interstellar medium and the solar wind plasma is crucial for determining the structures of the heliosphere. Since both the neutral-ion and neutral–neutral collision mean free paths are either comparable to or larger than the size of the heliosphere, the neutral phase space distribution can deviate far away from the Maxwellian distribution. A kinetic description for the neutrals is crucial for accurately modeling the heliosphere. It is computationally challenging to run three-dimensional time-dependent kinetic simulations due to the large number of macroparticles. In this paper, we present the new highly efficient Solar Wind with Hydrogen Ion Exchange and Large-scale Dynamics-2 model with a kinetic model of neutrals and a magnetohydrodynamic model for the ions and electrons. To improve the simulation efficiency, we implement adaptive mesh refinement and particle splitting and merging algorithms for the neutral particles to reduce the particle number that is required for an accurate simulation. We present several tests to verify and demonstrate the capabilities of the model.

Keywords: Heliosphere, Magnetohydrodynamical simulations
JWST NIRSpec High-resolution Spectroscopy of MACS0647–JD at z = 10.167: Resolved [O II] Doublet and Electron Density in an Early Galaxy. We present JWST/NIRSpec high-resolution G395H/F290LP spectroscopy of MACS0647‑JD, a gravitationally lensed galaxy merger at z = 10.167. The new spectroscopy, which is acquired for the two lensed images (JD1 and JD2), detects and resolves emission lines in the rest-frame ultraviolet and blue optical, including the resolved [O II] λ λ3726, 3729 doublet, [Ne III] λ3870, He I λ3890, Hδ, Hγ, and [O III] λ4363. This is the first observation of the resolved [O II] λ λ3726, 3729 doublet for a galaxy at z &gt; 8. We measure a line flux ratio [O II] λ3729/λ3726 = 0.9 ± 0.3, which corresponds to an estimated electron density of  log(ne/cm‑3)=2.9±0.5 . This is significantly higher than the electron densities of local galaxies reported in the literature. We compile measurements from the literature and further analyze the redshift evolution of n  e . We find that the redshift evolution follows the power-law form of n  e  = A × (1 + z) p  with  A=54‑23+31  cm‑3 and  p=1.2‑0.4+0.4 . This power-law form may be explained by a combination of metallicity and morphological evolution of galaxies, which become, on average, more metal poor and more compact with increasing redshift.

Keywords: Early universe, Strong gravitational lensing, Galaxy spectroscopy, High-redshift galaxies, Galaxies
FAST Survey of H I and OH Absorption toward Extragalactic Radio Sources. Neutral atomic hydrogen and molecular gas in the host galaxies of radio active galactic nuclei can be traced using H I 21 cm and OH-1667 MHz absorption lines to understand the fueling and feedback processes. We present the results of an H I and OH absorption survey with the Five-hundred-meter Aperture Spherical radio Telescope toward 40 radio sources of low–intermediate radio luminosity (∼1023–1026 W Hz‑1 at 1.4 GHz), red mid-infrared color (W2[4.6 μm]–W3[12 μm] &gt; 2.5 mag), and redshift up to 0.35. From 13 sources with good data at H I observing frequencies, we report the detection of H I absorption toward eight sources, five of which are new detections, including four in the redshift range 0.25–0.35. Our detection rates are consistent with our previous results, with the dependence on the star formation history of the host galaxies reflected in the mid-infrared Wide-field Infrared Survey Explorer W2‑W3 colors and the compactness of the radio sources. We find no significant dependence of the detection rates on radio luminosity or redshift. We also find that the H I column densities are anticorrelated with the low-frequency spectral indices ( α150MHz1.4GHz , S  ν  ∝ ν ‑α ). We do not have any detections from 23 sources with good data at OH observing frequencies. However, by stacking the spectra, we estimate the 3σ upper limit of the OH column density to be 2.27 × 1014 T ex/10 K × 1/f c cm‑2. By stacking the OH spectra for seven associated H I absorbers, we get a 3σ upper limit of 3.47 × 1014 T ex/10 K × 1/f c cm‑2 on the OH column density and 1.78 × 10‑7 on the [OH]/[H I] ratio.

Keywords: AGN host galaxies, Radio spectroscopy, Active galaxies, H I line emission, Radio continuum emission, Radio active galactic nuclei
Dependence of Spicule Properties on the Magnetic Field—Results from Magnetohydrodynamics Simulations. Solar spicules are plasma jets observed in the interface region between the visible solar surface and the corona. At any given time, there is a forest of spicules originating in the chromosphere of the Sun. While various models attempt to elucidate their origin and characteristics, here, we consider the one driven by the magnetoconvection undulations. The radiative magnetohydrodynamic (rMHD) equations are solved using PENCIL CODE with a spatial resolution of 16 km using various magnetic field strengths. The obtained rMHD simulation data are investigated to unveil the various trends in spicular properties as a function of the applied magnetic fields. The important outcome of this study is the finding of a consistent reduction in both the number density and the maximum height reached by spicules as magnetic field strength increases. We also use parabolic fitting on time–distance curves of spicules that are taller than the 75th percentile in the distribution, in order to find a relation between the deceleration of the spicule tip and the magnetic field strength. Our results offer insights into the response of solar spicules to magnetic field strength.

Keywords: Solar atmosphere, Radiative magnetohydrodynamics, Solar spicules, Solar physics, Solar magnetic fields, Magnetohydrodynamical simulations
Nonparametric Statistics on Magnetic Properties at the Footpoints of Erupting Magnetic Flux Ropes. It is under debate whether the magnetic field in the solar atmosphere carries neutralized electric currents, in particular, whether a magnetic flux rope (MFR), which is considered the core structure of coronal mass ejections, carries neutralized electric currents. Recently Wang et al. (2023) studied magnetic flux and electric current measured at the footpoints of 28 eruptive MFRs from 2010 to 2015. Because of the small sample size, no rigorous statistical analysis has been done. Here, we include nine more events from 2016 to 2023 and perform a series of nonparametric statistical tests at a significance level of 5%. The tests confirm that there exist no significant differences in magnetic properties between conjugated footpoints of the same MFR, which justifies the method of identifying the MFR footpoints through coronal dimming. The tests demonstrate that there exist no significant differences between MFRs with preeruption dimming and those with only posteruption dimming. However, there is a medium level of association between MFRs carrying substantial net current and those producing preeruption dimming, which can be understood by the Lorentz self-force of the current channel. The tests also suggest that in estimating the magnetic twist of MFRs, it is necessary to take into account the spatially inhomogeneous distribution of electric current density and magnetic field.

Keywords: Solar storm, Solar coronal mass ejections, Solar flares, Solar magnetic fields
Flux Rope Modeling of the 2022 September 5 Coronal Mass Ejection Observed by Parker Solar Probe and Solar Orbiter from 0.07 to 0.69 au. As both Parker Solar Probe (PSP) and Solar Orbiter (SolO) reach heliocentric distances closer to the Sun, they present an exciting opportunity to study the structure of coronal mass ejections (CMEs) in the inner heliosphere. We present an analysis of the global flux rope structure of the 2022 September 5 CME event that impacted PSP at a heliocentric distance of only 0.07 au and SolO at 0.69 au. We compare in situ measurements at PSP and SolO to determine global and local expansion measures, finding a good agreement between magnetic field relationships with heliocentric distance, but significant differences with respect to flux rope size. We use PSP/Wide-Field Imager for Solar Probe images as input to the ELlipse Evolution model based on Heliospheric Imager data (or ELEvoHI), providing a direct link between remote and in situ observations; we find a large discrepancy between the resulting modeled arrival times, suggesting that the underlying model assumptions may not be suitable when using data obtained close to the Sun, where the drag regime is markedly different in comparison to larger heliocentric distances. Finally, we fit the SolO's magnetometer and PSP's FIELDS data independently with the 3D Coronal ROpe Ejection (or 3DCORE) model, and find that many parameters are consistent between spacecraft. However, challenges are apparent when reconstructing a global 3D structure that aligns with arrival times at PSP and SolO, likely due to the large radial and longitudinal separations between spacecraft. From our model results, it is clear the solar wind background speed and drag regime strongly affect the modeled expansion and propagation of CMEs and need to be taken into consideration.

Keywords: Solar wind, Solar coronal mass ejections, Heliosphere, Dynamical evolution
Massive Quiescent Disk Galaxies at 0.5 ≤ z ≤ 1 in CANDELS: Color Gradients and Likely Origin. A rare population of massive disk-dominated quiescent galaxies has recently drawn much attention, which intrudes the red sequence (RS) population without destroying the underlying stellar disks. In this study, we have carefully identified 48 RS, disk-dominated galaxies with M * &gt; 1010 M ⊙ between redshift 0.5 and 1.0 in all five CANDELS fields. These galaxies are well fitted by a two-component bulge plus disk model, and have the bulge-to-total ratio B/T &lt; 0.4 in the both F814W and F160W bands. The fitting results indicate that these galaxies generally have extended stellar disks (∼3 kpc on average) and tiny bulge components (∼0.5 kpc on average). To understand their possible origins, we have also selected two control samples of 156 green valley (GV) and 309 blue cloud (BC) disk-dominated galaxies according to the same selection criteria. We study the UVI(U ‑ V versus V ‑ I) color gradients of these galaxies to infer their specific star formation rate (sSFR) gradients out to the maximum acceptable radii. We show that on average the disks in disk-dominated RS galaxies are fully quenched at all radii, whereas both the BC and GV disks are not fully quenched at any radii. We find that all the BC, GV, and RS disk galaxies generally have nearly flat sSFR profiles. We propose a potential formation mechanism, acknowledging that various other mechanisms (e.g., central compaction and active galactic nucleus feedback) might contribute, where massive quiescent disk-dominated galaxies are predominantly formed via a process of secular disk fading.

Keywords: Galaxy photometry, Star formation
Binary Mergers in the Centers of Galaxies: Synergy between Stellar Flybys and Tidal Fields. Galactic centers (GCs) are very dynamically active environments, often harboring a nuclear star cluster and supermassive black hole at their cores. Binaries in these environments are subject to strong tidal fields that can efficiently torque its orbit, exciting near-unity eccentricities that ultimately lead to their merger. In turn, frequent close interactions with passing stars impulsively perturb the orbit of the binary, generally softening their orbit until their evaporation, potentially hindering the role of tides to drive these mergers. In this work, we study the evolution of compact object binaries in the GC and their merger rates, focusing for the first time on the combined effect of the cluster's tidal field and flyby interactions. We find a significant synergy between both processes, where merger rates increase by a factor of ∼10‑30 compared to models in which only flybys or tides are taken into account. This synergy is a consequence of the persistent tides-driven eccentricity excitation that is enhanced by the gradual diffusion of j  z  driven by flybys. The merger efficiency peaks when the diffusion rate is ∼10‑100 slower than the tides-driven torquing. Added to this synergy, we also find that the gradual softening of the binary can lift the relativistic quenching of initially tight binaries, otherwise unable to reach extreme eccentricities, and thus expanding the available phase space for mergers. Cumulatively, we conclude that despite the gradual softening of binaries due to flybys, these greatly enhance their merger rates in GCs by promoting the tidal-field-driven eccentricity excitation.

Keywords: Supermassive black holes, Galactic center, Stellar dynamics, Compact objects, Star clusters
Imprints of the Local Bubble and Dust Complexity on Polarized Dust Emission. Using 3D dust maps and Planck polarized dust emission data, we investigate the influence of the 3D geometry of the nearby interstellar medium (ISM) on the statistics of the dust polarization on large ( 80' ) scales. We test recent models that assume that the magnetic field probed by the polarized dust emission is preferentially tangential to the Local Bubble wall, but we do not find an imprint of the Local Bubble geometry on the dust polarization fraction. We also test the hypothesis that the complexity of the 3D dust distribution drives some of the measured variation of the dust polarization fraction. We compare sight lines with similar total column densities and find that, on average, the dust polarization fraction decreases when the dust column is substantially distributed among multiple components at different distances. Conversely, the dust polarization fraction is higher for sight lines where the dust is more concentrated in 3D space. This finding is statistically significant for the dust within 1.25 kpc, but the effect disappears if we only consider dust within 270 pc. In conclusion, we find that the extended 3D dust distribution, rather than solely the dust associated with the Local Bubble, plays a role in determining the observed dust polarization fraction at 80'. This conclusion is consistent with a simple analytical prediction and remains robust under various modifications to the analysis. These results illuminate the relationship between the 3D geometry of the ISM and tracers of the interstellar magnetic field. We discuss implications for our understanding of the polarized dust foreground to the cosmic microwave background.

Keywords: Interstellar dust, Galaxy magnetic fields, Milky Way magnetic fields, Cosmic microwave background radiation, Interstellar dust extinction, Interstellar magnetic fields, Extinction, Interstellar reddening, Interstellar medium, Magnetic fields, Algorithms, Superbubbles
Galactic Chemical Evolution Models Favor an Extended Type Ia Supernova Delay-time Distribution. Type Ia supernovae (SNe Ia) produce most of the Fe-peak elements in the Universe and therefore are a crucial ingredient in galactic chemical evolution models. SNe Ia do not explode immediately after star formation, and the delay-time distribution (DTD) has not been definitively determined by supernova surveys or theoretical models. Because the DTD also affects the relationship among age, [Fe/H], and [α/Fe] in chemical evolution models, comparison with observations of stars in the Milky Way is an important consistency check for any proposed DTD. We implement several popular forms of the DTD in combination with multiple star formation histories for the Milky Way in multizone chemical evolution models that include radial stellar migration. We compare our predicted interstellar medium abundance tracks, stellar abundance distributions, and stellar age distributions to the final data release of the Apache Point Observatory Galactic Evolution Experiment. We find that the DTD has the largest effect on the [α/Fe] distribution: a DTD with more prompt SNe Ia produces a stellar abundance distribution that is skewed toward a lower [α/Fe] ratio. While the DTD alone cannot explain the observed bimodality in the [α/Fe] distribution, in combination with an appropriate star formation history it affects the goodness of fit between the predicted and observed high-α sequence. Our model results favor an extended DTD with fewer prompt SNe Ia than the fiducial t ‑1 power law.

Keywords: Galaxy chemical evolution, Chemical abundances, Chemical enrichment, Milky Way disk, Milky Way evolution, Milky Way Galaxy
PSR B0943+10: Mode Switch, Polar Cap Geometry, and Orthogonally Polarized Radiation. As one of the paradigm examples to probe into pulsar magnetospheric dynamics, PSR B0943+10 (J0946+0951) manifests representatively, showing a mode switch, orthogonal polarization, and subpulse drifting, frequently studied below 600 MHz. Here, both integrated and single pulses are studied at a high frequency (1.25 GHz) with FAST. The mode switch is studied using a profile decomposition method. A phase space evolution for the pulsar's mode switch shows a strange-attractor-like pattern. The radiative geometry is proposed by fitting polarization position angles with the rotating vector model. The pulsar pulse profile is then mapped to the sparking locations on the pulsar surface, and the differences between the main pulse's and the precursor component's radiative processes may explain the X-ray's synchronization with radio mode switch. Detailed single pulse studies on B0943+10's orthogonally polarized radiation are presented, which may support certain models of radiative transfer of polarized emission. In particular, the difference in orthogonal polarization modes' circular polarization might reflect the cyclotron absorption in pulsar magnetospheres. B0943+10's B and Q modes evolve differently with frequency and have different proportions of orthogonal modes, which indicates possible magnetospheric changes during mode switch. For Q mode pulse profile, the precursor and the main pulse components are orthogonally polarized, and are probably originated from different depths in the magnetosphere. The findings could impact significantly on the pulsar electrodynamics and the radiative mechanism related.

Keywords: Neutron stars, Magnetospheric radio emissions, Plasma astrophysics, Radiative processes, Polarimetry, Radio pulsars
Three Types of Solar Coronal Rain during Magnetic Reconnection between Open and Closed Magnetic Structures. Coronal rain (CR) is a crucial part of the mass cycle between the corona and chromosphere. It includes flare-driven CR and two types of quiescent CR, along nonflaring active region closed loops and along open structures, separately, labeled as type I, type II, and type III CR, respectively. Among them, type I and type III CR are generally associated with magnetic reconnection. In this study, employing data taken by the Solar Dynamics Observatory and the Solar Upper Transition Region Imager on 2022 October 11, we report three types of CR during an interchange reconnection between open and closed magnetic field structures above the southeastern solar limb. The open and closed structures converge, with the formation of the current sheet at the interface, and reconnect. The newly formed closed and open structures then recede from the reconnection region. During the reconnection, coronal condensation occurs along the reconnecting closed loops and falls toward the solar surface along both loop legs, as type II CR. Subsequently, condensation happens in the newly formed closed loops and moves down toward the solar surface along both loop legs, as type I CR. Magnetic dips of the reconnecting open structures form during the reconnection. In the dips, condensation occurs and propagates along the open structures toward the solar surface as type III CR. Our results suggest that the reconnection rate may be crucial for the formation of type I and type III CR during reconnection.

Keywords: Solar ultraviolet emission, Solar magnetic reconnection, Plasma physics, Solar corona, Solar magnetic fields