Sazuna/UAT_keywords huggingface dataset:
Removal of Active Region Inflows Reveals a Weak Solar Cycle Scale Trend in the Near-surface Meridional Flow. Using time-distance local helioseismology flow maps within 1 Mm of the solar photosphere, we detect inflows toward activity belts that contribute to solar-cycle scale variations in the near-surface meridional flow. These inflows stretch out as far as 30° away from the active region centroids. If active region neighborhoods are excluded, the solar-cycle-scale variation in the background meridional flow diminishes to below 2 m s-1, but still shows systematic variations in the absence of active regions between sunspot cycles 24 and 25. We therefore propose that the near-surface meridional flow is a three-component flow made up of a constant baseline flow profile that can be derived from quiet-Sun regions, variations due to inflows around active regions, and solar-cycle-scale variation of about 2 m s-1. Torsional oscillation, on the other hand, is found to be a global phenomenon, i.e., exclusion of active region neighborhoods does not significantly affect its magnitude or phase. This nonvariation in torsional oscillation with distance away from active regions and the three-component breakdown of the near-surface meridional flow serve as vital constraints for solar dynamo models and surface flux-transport simulations.

Keywords: Solar cycle, Solar active region velocity fields, Solar active region magnetic fields, Solar differential rotation, Solar interior, Helioseismology, Solar dynamo, Solar surface, Solar active regions, Solar physics, Solar magnetic fields, Solar meridional circulation
Absorption-line Observations of {{H}}_{3}(+) and CO in Sight Lines Toward the Vela and W28 Supernova Remnants. Supernova remnants act as particle accelerators, providing the cosmic-ray protons that permeate the interstellar medium and initiate the ion-molecule reactions that drive interstellar chemistry. Enhanced fluxes of cosmic-ray protons in close proximity to supernova remnants have been inferred from observations tracing particle interactions with nearby molecular gas. Here I present observations of ${{\rm{H}}}_{3}^{+}$ and CO absorption, molecules that serve as tracers of the cosmic-ray ionization rate and gas density, respectively, in sight lines toward the W28 and Vela supernova remnants. Cosmic-ray ionization rates inferred from these observations range from about 2 to 10 times the average value in Galactic diffuse clouds (~3 × 10-16 s-1), suggesting that the gas being probed is experiencing an elevated particle flux. While it is difficult to constrain the line-of-sight locations of the absorbing gas with respect to the supernova remnants, these results are consistent with a scenario where cosmic rays are diffusing away from the acceleration site and producing enhanced ionization rates in the surrounding medium.

Keywords: Supernova remnants, Diffuse molecular clouds, Infrared spectroscopy, Cosmic rays
Observational Evidence of S-web Source of the Slow Solar Wind. From 2022 March 18 to 21, NOAA Active Region (AR) 12967 was tracked simultaneously by Solar Orbiter at 0.35 au and Hinode/EIS at Earth. During this period, strong blueshifted plasma upflows were observed along a thin, dark corridor of open magnetic field originating at the AR's leading polarity and continuing toward the southern extension of the northern polar coronal hole. A potential field source surface model shows large lateral expansion of the open magnetic field along the corridor. Squashing factor Q-maps of the large-scale topology further confirm super-radial expansion in support of the S-web theory for the slow wind. The thin corridor of upflows is identified as the source region of a slow solar wind stream characterized by ~300 km s-1 velocities, low proton temperatures of ~5 eV, extremely high density &gt;100 cm-3, and a short interval of moderate Alfvénicity accompanied by switchback events. When the connectivity changes from the corridor to the eastern side of the AR, the in situ plasma parameters of the slow solar wind indicate a distinctly different source region. These observations provide strong evidence that the narrow open-field corridors, forming part of the S-web, produce some extreme properties in their associated solar wind streams.

Keywords: Slow solar wind
EIGER. I. A Large Sample of [O III]-emitting Galaxies at 5.3 &lt; z &lt; 6.9 and Direct Evidence for Local Reionization by Galaxies. We present a first sample of 117 [O III] λλ4960, 5008-selected star-forming galaxies at 5.33 &lt; z &lt; 6.93 detected in JWST/NIRCam 3.5 μm slitless spectroscopy of a $6\buildrel{\,\prime}\over{.} 5\,\times \,3\buildrel{\,\prime}\over{.} 4$ field centered on the hyperluminous quasar SDSS J0100+2802, obtained as part of the Emission-line galaxies and Intergalactic Gas in the Epoch of Reionization (EIGER) survey. Three prominent galaxy overdensities are observed, one of them at the redshift of the quasar. Galaxies are found within 200 pkpc and 105 km s-1 of four known metal absorption-line systems. We focus on the role of the galaxies in ionizing the intergalactic medium (IGM) during the later stages of cosmic reionization and construct the mean Lyα and Lyβ transmission as a function of distance from the galaxies. At the lowest redshifts in our study, 5.3 &lt; z &lt; 5.7, the IGM transmission rises monotonically with distance from the galaxies, as seen previously at lower redshifts. In contrast, at 5.7 &lt; z &lt; 6.14, the transmission of both Lyα and Lyβ first increases with distance but then peaks at a distance of 5 cMpc before declining. Finally, in the region 6.15 &lt; z &lt; 6.26, where the additional ionizing radiation from the quasar dominates, the monotonic increase in transmission with distance is reestablished. This result is interpreted to represent evidence that the transmission of the IGM at z ~ 5.9 toward J0100+2802 results from the "local" ionizing radiation of galaxies that dominates over the much-reduced cosmic background.

Keywords: Intergalactic medium, Protoclusters, Emission line galaxies, Galaxy evolution, Circumgalactic medium, Reionization, High-redshift galaxies
EIGER. II. First Spectroscopic Characterization of the Young Stars and Ionized Gas Associated with Strong Hβ and [O III] Line Emission in Galaxies at z = 5-7 with JWST. We present emission-line measurements and physical interpretations for a sample of 117 [O III] emitting galaxies at z = 5.33-6.93, using the first deep JWST/NIRCam wide-field slitless spectroscopic observations. Our 9.7 hr integration is centered upon the z = 6.3 quasar J0100+2802-the first of six fields targeted by the EIGER survey-and covers λ = 3-4 μm. We detect 133 [O III] doublets, but close pairs motivated by their small scale clustering excess. The galaxies are characterized by a UV luminosity M UV ~ -19.6 (-17.7 to -22.3), stellar mass ~108 (106.8-10.1) M ⊙, Hβ and [O III]4960+5008 EWs ≈ 850 Å (up to 3000 Å), young ages, a highly excited interstellar medium, and low dust attenuations. These high EWs are very rare in the local universe, but we show they are ubiquitous at z ~ 6 based on the measured number densities. The stacked spectrum reveals Hγ and [O III]4364, which shows that the galaxies are typically dust- and metal-poor (E (B - V) = 0.1, $12+\mathrm{log}({\rm{O}}/{\rm{H}})=7.4$ ) with a high electron temperature (2 × 104 K) and a production efficiency of ionizing photons (ξ ion = 1025.3 Hz erg-1). We further show the existence of a strong mass-metallicity relation. The properties of the stars and gas in z ~ 6 galaxies conspire to maximize the [O III] output from galaxies, yielding an [O III] luminosity density at z ≈ 6 that is significantly higher than that at z ≈ 2. Thus, [O III] emission-line surveys with JWST prove a highly efficient method to trace the galaxy density in the Epoch of Reionization.

Keywords: Galaxy formation, Chemical abundances, Interstellar medium, Reionization, High-redshift galaxies
EIGER. III. JWST/NIRCam Observations of the Ultraluminous High-redshift Quasar J0100+2802. We present the first rest-frame optical spectrum of a high-redshift quasar observed with JWST/NIRCam in Wide Field Slitless mode. The observed quasar, J0100+2802, is the most luminous quasar known at z &gt; 6. We measure the mass of the central supermassive black hole (SMBH) by means of the rest-frame optical H β emission line, and find consistent mass measurements of the quasar's SMBH of M ∙ ≈ 1010 M ☉ when compared to the estimates based on the properties of rest-frame UV emission lines C IV and Mg II, which are accessible from ground-based observatories. To this end, we also present a newly reduced rest-frame UV spectrum of the quasar observed with X-Shooter/Very Large Telescope (VLT) and FIRE/Magellan for a total of 16.8 hr. We readdress the question whether this ultraluminous quasar could be effected by strong gravitational lensing making use of the diffraction limited NIRCam images in three different wide band filters (F115W, F200W, F356W), which improves the achieved spatial resolution compared to previous images taken with the Hubble Space Telescope by a factor of 2. We do not find any evidence for a foreground deflecting galaxy, nor for multiple images of the quasar, and determine the probability for magnification due to strong gravitational lensing with image separations below the diffraction limit of ∆θ ≲ 0.″05 to be ≲2.2 × 10-3. Our observations therefore confirm that this quasar hosts a 10 billion solar mass black hole less than 1 Gyr after the Big Bang, which is challenging to explain with current black hole formation models.

Keywords: Observational astronomy, Early universe, Supermassive black holes, Quasars, Strong gravitational lensing, Gravitational lensing, Astronomical methods
Insight-HXMT Detections of Hard X-Ray Tails in Scorpius X-1. Using the observations of the high-energy detector of the Hard X-ray Modulation Telescope (Insight-HXMT) for Scorpius X-1 from 2017 to 2020, we search for hard X-ray tails in the X-ray spectra in ~30-200 keV. The hard X-ray tails are found throughout the Z-track on the hardness-intensity diagram, and the detected hard X-ray tails become hard and weak from the horizontal branch (HB), through the normal branch (NB), to the flaring branch (FB). Comparing the hard X-ray spectra of Insight-HXMT between Cyg X-1 and Sco X-1, it is concluded that the hard X-ray spectrum of Cyg X-1 shows a high-energy cutoff, implying a hot corona in it, but the high-energy cutoff is not seen in the hard X-ray spectrum of Sco X-1. From fitting the broadband spectrum of Sco X-1 in ~2-200 keV, it is proposed that the hard X-ray tails in the HB and NB can be explained by the overall Comptonization COMPTB model, suggesting that the hard X-ray tails could have resulted from the Comptonization of the photons from the neutron star (NS) surface by the thermal electrons in the region between the NS and the disk and the energetic electrons in the freefall toward the NS in the converging flow onto the NS. However, this model cannot be responsible for the hard X-ray tails in the FB. Further study on the FB hard X-ray tails is needed.

Keywords: Neutron stars, Low-mass x-ray binary stars, X-ray binary stars, Non-thermal radiation sources
Learning Neutrino Effects in Cosmology with Convolutional Neural Network. Measuring the sum of the three active neutrino masses, M  ν , is one of the most important challenges in modern cosmology. Massive neutrinos imprint characteristic signatures on several cosmological observables, in particular, on the large-scale structure of the universe. In order to maximize the information that can be retrieved from galaxy surveys, accurate theoretical predictions in the nonlinear regime are needed. Currently, one way to achieve those predictions is by running cosmological numerical simulations. Unfortunately, producing those simulations requires high computational resources-several hundred to thousand core hours for each neutrino mass case. In this work, we propose a new method, based on a deep-learning network (D3M), to quickly generate simulations with massive neutrinos from standard ΛCDM simulations without neutrinos. We computed multiple relevant statistical measures of deep-learning generated simulations and conclude that our approach is an accurate alternative to the traditional N-body techniques. In particular the power spectrum is within ≃6% down to nonlinear scales k = 0.7 h Mpc-1. Finally, our method allows us to generate massive neutrino simulations 10,000 times faster than the traditional methods.

Keywords: Cosmology, Large-scale structure of the universe, Cosmological parameters from large-scale structure, Cosmological neutrinos, N-body simulations
Energy-releasing Process for the 2013 May 13 X1.7 Limb Flare: A Continued Study. In this paper, we reanalyze the X1.7 class limb flare that occurred on 2013 May 13 (SOL2013-05-13T01:56 UT), concentrating on the energy-releasing process using microwave observations mainly made by Nobeyama and X-ray observations made by RHESSI. The analysis was carried out in the context of EUV observations made by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory. First, we complement the initiation process by showing that the initiation occurred together with material falling from a large-scale overlying prominence, a signature of drainage instability. The usual downward and upward motions of the microwave and X-ray sources are observed from their evolution. However, the microwave source's height shows a recurrent decrease and increase during its overall upward motion; it shows a kind of recurrent contraction and expansion. The time period of the recurrent contraction and expansion corresponds to the period of post-contraction oscillation of EUV loops, and the oscillatory motions are closely correlated with four microwave/hard X-ray peaks that unusually increased nonthermal emission levels by several times. X-ray spectra get hardened during the oscillation. In addition, the rapid contraction of magnetic loops located on the outside of the erupting flux rope occurs 5 minutes after the onset of the flare, showing that the contraction of the peripheral magnetic loops is more likely due to the vortex and sink flows generated by an upward erupting magnetic flux rope rather than a coronal implosion. The results can provide more insight into the physics of dynamic coronal magnetic field and particle acceleration during solar flares.

Keywords: Solar flares, Solar magnetic reconnection, Solar radio emission, X-ray sources, Solar activity
Multiphase Gas Nature in the Sub-parsec Region of the Active Galactic Nuclei. I. Dynamical Structures of Dusty and Dust-free Outflow. We investigated dusty and dust-free gas dynamics for a radiation-driven sub-parsec-scale outflow in an active galactic nucleus (AGN) associated with a supermassive black hole 107 M ⊙ and bolometric luminosity 1044 erg s-1 based on the two-dimensional radiation-hydrodynamic simulations. A radiation-driven "lotus-like" multi-shell outflow is launched from the inner part (r ≲ 0.04 pc) of the geometrically thin disk, and it repeatedly and steadily produces shocks as mass accretion continues through the disk to the center. The shape of the dust sublimation radius is not spherical and depends on the angle (θ) from the disk plane, reflecting the nonspherical radiation field and nonuniform dust-free gas. Moreover, we found that the sublimation radius of θ ~ 20°-60° varies on a timescale of several years. The "inflow-induced outflow" contributes to the obscuration of the nucleus in the sub-parsec region. The column density of the dust-free gas is N H ≳ 1022 cm-2 for r ≲ 0.04 pc. Gases near the disk plane (θ ≲ 30°) can be the origin of the Compton-thick component, which was suggested by the recent X-ray observations of AGNs. The dusty outflow from the sub-parsec region can be also a source of material for the radiation-driven fountain for a larger scale.

Keywords: Astrophysical dust processes, Hydrodynamical simulations, Active galactic nuclei, Hydrodynamics
Heat Transport and Convective Velocities in Compositionally Driven Convection in Neutron Star and White Dwarf Interiors. We investigate heat transport associated with compositionally driven convection driven by crystallization at the ocean-crust interface in accreting neutron stars, or growth of the solid core in cooling white dwarfs. We study the effect of thermal diffusion and rapid rotation on the convective heat transport, using both mixing length theory and numerical simulations of Boussinesq convection. We determine the heat flux, composition gradient, and Péclet number, Pe (the ratio of thermal diffusion time to convective turnover time) as a function of the composition flux. We find two regimes of convection with a rapid transition between them as the composition flux increases. At small Pe, the ratio between the heat flux and composition flux is independent of Pe, because the loss of heat from convecting fluid elements due to thermal diffusion is offset by the smaller composition gradient needed to overcome the reduced thermal buoyancy. At large Pe, the temperature gradient approaches the adiabatic gradient, saturating the heat flux. We discuss the implications for cooling of neutron stars and white dwarfs. Convection in neutron stars spans both regimes. We find rapid mixing of neutron star oceans, with a convective turnover time of the order of weeks to minutes depending on rotation. Except during the early stages of core crystallization, white dwarf convection is in the thermal-diffusion-dominated fingering regime. We find convective velocities much smaller than recent estimates for crystallization-driven dynamos. The small fraction of energy carried as kinetic energy calls into question the effectiveness of crystallization-driven dynamos as an explanation for observed magnetic fields in white dwarfs.

Keywords: Neutron stars, White dwarf stars, X-ray binary stars, Stellar convective zones
The Large Magellanic Cloud Supernova Remnant MCSNR J0550-6823. We describe radio, optical, and X-ray observations of this rather faint, old Large Magellanic Cloud (LMC) supernova remnant. The [O III] emission forms a distinct shell, the remnant of the outer shock, which encloses the radio and X-ray emission and gives an estimate of age and explosion energy. Because of a collision with an LMC Hα filament, radio and X-ray emission are concentrated in the northern half of the remnant. The X-ray spectrum is well fit assuming the plasma is isothermal and in collisional equilibrium. The best-fit temperature is such that almost all energy is in lines from O, Ne, Mg, and Fe. The known distance, low extinction, and low interstellarmedium metallicity allow derivation of masses of several elements produced by the star and in the explosion. The masses of O, Ne, and Fe point to a Type II supernova from the explosion of a 20-25 M ⊙ star. The mass of Mg, however, is higher than that of almost all predictions, but some of this apparent excess might be due to a higher-temperature region in the X-ray-emitting material. Point-like background sources are examined to search for a neutron star, and one possible candidate is found just inside the shell of the remnant.

Keywords: X-ray astronomy, Type II supernovae, Supernova remnants, Large Magellanic Cloud
Dense Molecular Gas Properties of the Central Kiloparsec of Nearby Ultraluminous Infrared Galaxies Constrained by ALMA Three Transition-line Observations. We report the results of Atacama Large Millimeter/submillimeter Array (ALMA) 1-2 kpc resolution, three rotational transition-line (J = 2-1, J = 3-2, and J = 4-3) observations of multiple dense molecular gas tracers (HCN, HCO+, and HNC) for 10 nearby (ultra)luminous infrared galaxies ((U)LIRGs). Following the matching of beam sizes to 1-2 kpc for each (U)LIRG, the high-J-to-low-J transition-line flux ratios of each molecule and the emission-line flux ratios of different molecules at each J transition are derived. We conduct RADEX non-LTE model calculations and find that, under a wide range of gas density and kinetic temperature, the observed HCN-to-HCO+ flux ratios in the overall (U)LIRGs are naturally reproduced with enhanced HCN abundance compared to HCO+. Thereafter, molecular gas properties are constrained primarily through the use of HCN and HCO+ data and the adoption of fiducial values for the HCO+ column density and HCN-to-HCO+ abundance ratio. We quantitatively confirm the following: (i) molecular gas at the (U)LIRGs' nuclei is dense (≳103-4 cm-3) and warm (≳100 K), (ii) the molecular gas density and temperature in nine ULIRGs' nuclei are significantly higher than those of one LIRG's nucleus, (iii) molecular gas in starburst-dominated sources tends to be less dense and cooler than ULIRGs with luminous AGN signatures. For six selected sources, we also apply a Bayesian approach by freeing all parameters and support the above main results. Our ALMA 1-2 kpc resolution, multiple transition-line data of multiple molecules are a very powerful tool for scrutinizing the properties of molecular gas concentrated around luminous energy sources in nearby (U)LIRGs' nuclei.

Keywords: Supermassive black holes, Starburst galaxies, Molecular gas, Millimeter astronomy, Molecular spectroscopy, Active galaxies, Active galactic nuclei, Galaxy mergers, Submillimeter astronomy, Radio interferometry, Ultraluminous infrared galaxies, Luminous infrared galaxies
X-Ray Polarimetry of the Accreting Pulsar 1A 0535+262 in the Supercritical State with PolarLight. The X-ray pulsar 1A 0535+262 exhibited a giant outburst in 2020, offering us a unique opportunity for X-ray polarimetry of an accreting pulsar in the supercritical state. Measurement with PolarLight yielded a nondetection in 3-8 keV; the 99% upper limit of the polarization fraction (PF) is found to be 0.34 averaged over spin phases, or 0.51 based on the rotating vector model. No useful constraint can be placed with phase-resolved polarimetry. These upper limits are lower than a previous theoretical prediction of 0.6-0.8, but consistent with those found in other accreting pulsars, like Her X-1, Cen X-3, 4U 1626-67, and GRO J1008-57, which were in the subcritical state, or at least not confidently in the supercritical state, during the polarization measurements. Our results suggest that the relatively low PF seen in accreting pulsars cannot be attributed to the source not being in the supercritical state, but could be a general feature.

Keywords: Polarimetry, X-ray sources, Pulsars
Nonparametric Representation of Neutron Star Equation of State Using Variational Autoencoder. We introduce a new nonparametric representation of the neutron star (NS) equation of state (EOS) by using the variational autoencoder (VAE). As a deep neural network, the VAE is frequently used for dimensionality reduction since it can compress input data to a low-dimensional latent space using the encoder component and then reconstruct the data using the decoder component. Once a VAE is trained, one can take the decoder of the VAE as a generator. We employ 100,000 EOSs that are generated using the nonparametric representation method based on Han et al. as the training set and try different settings of the neural network, then we get an EOS generator (the trained VAE's decoder) with four parameters. We use the mass-tidal-deformability data of binary NS merger event GW170817, the mass-radius data of PSR J0030+0451, PSR J0740+6620, PSR J0437-4715, and 4U 1702-429, and the nuclear constraints to perform the Bayesian inference. The overall results of the analysis that includes all the observations are ${R}_{1.4}={12.59}_{-0.42}^{+0.36}\,\mathrm{km}$ , ${{\rm{\Lambda }}}_{1.4}={489}_{-110}^{+114}$ , and ${M}_{\max }={2.20}_{-0.19}^{+0.37}\,{M}_{\odot }$ (90% credible levels), where R 1.4/Λ1.4 are the radius/tidal deformability of a canonical 1.4 M ⊙ NS, and ${M}_{\max }$ is the maximum mass of a nonrotating NS. The results indicate that the implementation of these VAE techniques can obtain reasonable results, while accelerating calculation by a factor of ~3-10 or more, compared with the original method.

Keywords: Neutron stars, Nonparametric inference