Sazuna/UAT_keywords huggingface dataset:
Observations and Modeling of Unstable Proton and α Particle Velocity Distributions in Sub-Alfvénic Solar Wind at Parker Solar Probe Perihelia. Past observations show that solar wind (SW) acceleration occurs inside the sub-Alfvénic region, reaching the local Alfvén speed at typical distances ~10-20 solar radii (R  s ). Recently, Parker Solar Probe (PSP) traversed regions of sub-Alfvénic SW near perihelia in encounters E8-E12 for the first time, providing data in these regions. It became evident that the properties of the magnetically dominated SW are considerably different from the super-Alfvénic wind. For example, there are changes in the relative abundances and drift of α particles with respect to protons, as well as in the magnitude of magnetic fluctuations. We use data of the magnetic field from the FIELDS instrument, and construct ion velocity distribution functions (VDFs) from the sub-Alfvénic regions using Solar Probe ANalyzer for Ions data, and run 2.5D and 3D hybrid models of proton-α sub-Alfvénic SW plasma. We investigate the nonlinear evolution of the ion kinetic instabilities in several case studies, and quantify the transfer of energy between the protons, α particles, and the kinetic waves. The models provide the 3D ion VDFs at the various stages of the instability evolution in the SW frame. By combining observational analysis with the modeling results, we gain insights on the evolution of the ion instabilities, the heating and the acceleration processes of the sub-Alfvénic SW plasma, and quantify the exchange of energy between the magnetic and kinetic components. The modeling results suggest that the ion kinetic instabilities are produced locally in the SW, resulting in anisotropic heating of the ions, as observed by PSP.

Keywords: Space plasmas, Solar wind, Heliosphere
Dust Enrichment and Grain Growth in a Smooth Disk around the DG Tau Protostar Revealed by ALMA Triple Bands Frequency Observations. Characterizing the physical properties of dust grains in a protoplanetary disk is critical to comprehending the planet formation process. Our study presents Atacama Large Millimeter/submillimeter Array (ALMA) high-resolution observations of the young protoplanetary disk around DG Tau at a 1.3 mm dust continuum. The observations, with a spatial resolution of ≈0.″04, or ≈5 au, revealed a geometrically thin and smooth disk without substantial substructures, suggesting that the disk retains the initial conditions of the planet formation. To further analyze the distributions of dust surface density, temperature, and grain size, we conducted a multiband analysis with several dust models, incorporating ALMA archival data of the 0.87 and 3.1 mm dust polarization. The results showed that the Toomre Q parameter is ≲2 at a 20 au radius, assuming a dust-to-gas mass ratio of 0.01. This implies that a higher dust-to-gas mass ratio is necessary to stabilize the disk. The grain sizes depend on the dust models, and for the DSHARP compact dust, they were found to be smaller than ~400 μm in the inner region (r ≲ 20 au) while exceeding larger than 3 mm in the outer part. Radiative transfer calculations show that the dust scale height is lower than at least one-third of the gas scale height. These distributions of dust enrichment, grain sizes, and weak turbulence strength may have significant implications for the formation of planetesimals through mechanisms such as streaming instability. We also discuss the CO snowline effect and collisional fragmentation in dust coagulation for the origin of the dust size distribution.

Keywords: Young stellar objects, Dust continuum emission, Protoplanetary disks, Star formation, Circumstellar disks, Protostars, Planet formation
NY Bootes: An Active Deep and Low-mass-ratio Contact Binary with a Cool Companion in a Hierarchical Triple System. The first detailed photometric and spectroscopic study of G-type short-period binary NY Boo is presented. The radial velocity curve was obtained by the cross-correlation function (CCF) method based on LAMOST and SDSS spectra, which derived its mass ratio as q = 0.139(1/7.2). The CCF profiles of the SDSS spectra clearly show the existence of a cool third component, which is supported by the results of the orbital period investigation. The period study based on the O-C analysis indicates that besides a long-term decrease, the orbital period has a periodic oscillation due to the light-travel time effect caused by a third body. When the third light contribution is consistent with the CCF results, the orbit of the third body and the inner pair are non-coplanar with m 3 = 0.31 M ☉. Combining with the TESS light curves, it is found that the target is a deep and low-mass-ratio contact binary (DLMRCB) with a fill-out factor of f = 73%. The notable asymmetry in light curves was detected and explained by the spot model very well. The spectroscopic profiles, the cyclic variation in the O-C diagram, and the radial velocity curve and light-curve solutions all suggest that NY Boo is a hierarchical triple system with a cool tertiary component orbiting around an active DLMRCB. With the orbital period shrinking, the binary may eventually merge. The period of NY Boo decreases faster than other shrinking DLMRCB, together with active inner pair and non-coplanar tertiary component, making NY Boo an important target for studying the late evolution of binaries.

Keywords: Close binary stars, Eclipsing binary stars, Binary stars
Examining Neutrino-Matter Interactions in the Cassiopeia A Supernova. Neutrino interactions with stellar material are widely believed to be fundamental to the explosion of massive stars. However, this important process has remained difficult to confirm observationally. We propose a new method to verify it using X-ray observations of the supernova remnant Cassiopeia A. The elemental composition in its Fe-rich ejecta that could have been produced at the innermost region of the supernova, where neutrinos are expected to interact, allows us to examine the presence of neutrino interactions. Here we demonstrate that the amount of Mn produced without neutrino nucleosynthesis processes (i.e., the ν- and νp-processes) is too small to explain the Mn/Fe mass ratio we measure (0.14%-0.67%). This result supports the operation of significant neutrino interactions in the Cassiopeia A supernova. If the observed Mn/Fe mass ratio purely reflects the production at the innermost region of the supernova, this would be the first robust confirmation of neutrino-matter interactions in an individual supernova. We further show that the Mn/Fe mass ratio has the potential to constrain supernova neutrino parameters (i.e., total neutrino luminosity, neutrino temperature). Future spatially resolved, high-resolution X-ray spectroscopy will allow us to investigate the details of neutrino-supernova astrophysics through its signatures in elemental composition not only in Cassiopeia A but also in other remnants.

Keywords: X-ray astronomy, Supernova neutrinos, Explosive nucleosynthesis, Nucleosynthesis, Supernova remnants, Interstellar medium
Evolution of Nonparametric Morphology of Galaxies in the JWST CEERS Field at z ≃ 0.8-3.0. Galaxy morphology is one of the most fundamental ways to describe galaxy properties, but the morphology we observe may be affected by wavelength and spatial resolution, which may introduce systematic bias when comparing galaxies at different redshift. Taking advantage of the broad wavelength coverage from optical to near-IR and the high-resolution NIRCam instrument of the JWST, we measure the nonparametric morphological parameters of a total of 1376 galaxies at z ≃ 0.8-3.0 in the CEERS field through an optimized code called statmorph_csst. We divide our sample into three redshift intervals and investigate the wavelength and redshift dependence of the morphological parameters. We also explore how the widely used galaxy type classification methods based on the morphological parameters depend on wavelength and spatial resolution. We find that there are variations in all morphological parameters with rest-frame wavelength (λ rf), especially at the short-wavelength end, and that λ rf mainly affects the classification between late- and early-type galaxies. As λ rf increases, the galaxies on the G-M 20 diagram move to the upper left with a slope of -0.23 ± 0.03 on average. We find that spatial resolution mainly affects the merger identification. The merger fraction in F200W resolution can be ≳2 times larger than that in F444W resolution. Furthermore, we compare the morphological parameter evolution of galaxies with different stellar masses. We find that there are differences in the morphological evolution of high- and low-mass (log M * ≥ 10 and 9 &lt; log M * &lt; 10) galaxies in the studied redshift range, which may be caused by their different evolutionary paths.

Keywords: Galaxy evolution, Galaxy structure, High-redshift galaxies, Galaxy classification systems
Neutrino-driven Winds in Three-dimensional Core-collapse Supernova Simulations. In this paper, we analyze the neutrino-driven winds that emerge in 12 unprecedentedly long-duration 3D core-collapse supernova simulations done using the code FORNAX. The 12 models cover progenitors with zero-age main-sequence mass between 9 and 60 solar masses. In all our models, we see transonic outflows that are at least 2 times as fast as the surrounding ejecta and that originate generically from a proto-neutron star surface atmosphere that is turbulent and rotating. We find that winds are common features of 3D simulations, even if there is anisotropic early infall. We find that the basic dynamical properties of 3D winds behave qualitatively similarly to those inferred in the past using simpler 1D models, but that the shape of the emergent wind can be deformed, very aspherical, and channeled by its environment. The thermal properties of winds for less massive progenitors very approximately recapitulate the 1D stationary solutions, while for more massive progenitors they deviate significantly owing to aspherical accretion. The Y  e  temporal evolution in winds is stochastic, and there can be some neutron-rich phases. Though no strong r-process is seen in any model, a weak r-process can be produced, and isotopes up to 90Zr are synthesized in some models. Finally, we find that there is at most a few percent of a solar mass in the integrated wind component, while the energy carried by the wind itself can be as much as 10%-20% of the total explosion energy.

Keywords: Nucleosynthesis, Supernova dynamics, Core-collapse supernovae
The Baryonic Content of Galaxies Mapped by MaNGA and the Gas Around Them. We analyze the cool gas in and around 14 nearby galaxies (at z &lt; 0.1) mapped with the Sloan Digital Sky Survey IV MaNGA survey by measuring absorption lines produced by gas in spectra of background quasars/active galactic nuclei at impact parameters of 0-25 effective radii from the galactic centers. Using Hubble Space Telescope/Cosmic Origins Spectrograph, we detect absorption at the galactic redshift and measure or constrain column densities of neutral (H I, N I, O I, and Ar I), low-ionization (Si II, S II, C II, N II, and Fe II), and high-ionization (Si III, Fe III, N V, and O VI) species for 11 galaxies. We derive the ionization parameter and ionization-corrected metallicity using CLOUDY photoionization models. The H I column density ranges from ~1013 to ~1020 cm-2 and decreases with impact parameter for r ≳ R  e . Galaxies with higher stellar mass have weaker H I absorption. Comparing absorption velocities with MaNGA radial velocity maps of ionized gas line emissions in galactic disks, we find that the neutral gas seen in absorption corotates with the disk out to ~10 R  e . Sight lines with lower elevation angles show lower metallicities, consistent with the metallicity gradient in the disk derived from MaNGA maps. Higher-elevation angle sight lines show higher ionization, lower H I column density, supersolar metallicity, and velocities consistent with the direction of galactic outflow. Our data offer the first detailed comparisons of circumgalactic medium (CGM) properties (kinematics and metallicity) with extrapolations of detailed galaxy maps from integral field spectroscopy; similar studies for larger samples are needed to more fully understand how galaxies interact with their CGM.

Keywords: Quasar absorption line spectroscopy, Observational cosmology, Star formation, Galaxy evolution, Interstellar medium
NuSTAR Observations of Four Mid-IR-Selected Dual AGN Candidates in Galaxy Mergers. Mergers of galaxies are a ubiquitous phenomenon in the universe and represent a natural consequence of the "bottom-up" mass accumulation and galaxy evolution cosmological paradigm. It is generally accepted that the peak of active galactic nucleus (AGN) accretion activity occurs at nuclear separations of ≲10 kpc for major mergers. Here we present new NuSTAR and XMM-Newton observations for a subsample of mid-IR preselected dual AGN candidates in an effort to better constrain the column densities along the line of sight (LOS) for each system. Only one dual AGN candidate, J0841+0101, is detected as a single, unresolved source in the XMM-Newton and NuSTAR imaging, while the remaining three dual AGN candidates, J0122+0100, J1221+1137, and J1306+0735, are not detected with NuSTAR; if these nondetections are due to obscuration alone, these systems are consistent with being absorbed by column densities of log(N H/cm-2) ≥ 24.9, 24.6, and 24.3, which are roughly consistent with previously inferred column densities in these merging systems. In the case of J0841+0101, the analysis of the 0.3-30 keV spectra reveal an LOS column density of N H ≳ 1024 cm-2, significantly larger than the column densities previously reported for this system and demonstrating the importance of the higher signal-to-noise ratio XMM-Newton spectra and access to the &gt;10 keV energies via NuSTAR. Though it is unclear if J0841+0101 truly hosts a dual AGN, these results are in agreement with the high obscuring columns expected in AGNs in late-stage mergers.

Keywords: AGN host galaxies, Galaxy mergers
Slowly Rotating Accretion Flow Around Supermassive Black Holes in Elliptical Galaxies: Case With Outflow. Observational evidence and many numerical simulations show the existence of winds (i.e., uncollimated outflows) in the accretion systems of elliptical galaxy centers. One of the primary aims of this study is to investigate the solutions of slowly rotating accretion flows around supermassive black holes with outflows. This paper presents two distinct physical regions, supersonic and subsonic, which extend from the outer boundary to the black hole. In our numerical solution, the outer boundary is chosen beyond the Bondi radius. Due to strong gravity, we ignore outflow (i.e., s = 0) in the inner region (within ~10r  s ). The radial velocity of the flow at the outer region is significantly increased due to the presence of the outflow. Compared to previous works, the accretion mode, namely, the slowly rotating case, that corresponds to low accretion rates that have general wind output is carefully described, and the effect of the galaxy potential and feedback by the wind in this mode are taken into account. As the power-law form of the mass accretion rate is mathematically compatible with our equations, we consider a radius-dependent mass accretion rate ( ${\dot{M}}_{\mathrm{in}}\propto {r}^{s}$ ), where s is a free parameter and shows the intensity of outflow. There is an unknown mechanism for removing the mass, angular momentum, and energy by outflows in this study. The effects of the outflow appear well on the outer edge of the flow.

Keywords: Accretion, Elliptical galaxies
Scaling of Magnetic Reconnection Electron Bulk Heating in the High-Alfvén-speed and Low-β Regime of Earth's Magnetotail. We have surveyed 21 reconnection exhaust events observed by Magnetospheric MultiScale in the low-plasma-β and high-Alfvén-speed regime of the Earth's magnetotail to investigate the scaling of electron bulk heating produced by reconnection. The ranges of inflow Alfvén speed and inflow electron β e covered by this study are 800-4000 km s-1 and 0.001-0.1, respectively, and the observed heating ranges from a few hundred electronvolts to several kiloelectronvolts. We find that the temperature change in the reconnection exhaust relative to the inflow, ΔT e, is correlated with the inflow Alfvén speed, V Ax,in, based on the reconnecting magnetic field and the inflow plasma density. Furthermore, ΔT e is linearly proportional to the inflowing magnetic energy per particle, ${{m}_{{\rm{i}}}{V}_{\mathrm{Ax},\mathrm{in}}}^{2}$ , and the best fit to the data produces the empirical relation ΔT e = 0.020 ${{m}_{{\rm{i}}}{V}_{\mathrm{Ax},\mathrm{in}}}^{2}$ , i.e., the electron temperature increase is on average ~2% of the inflowing magnetic energy per particle. This magnetotail study extends a previous magnetopause reconnection study by two orders of magnitude in both magnetic energy and electron β, to a regime that is comparable to the solar corona. The validity of the empirical relation over such a large combined magnetopause-magnetotail plasma parameter range of V A ~ 10-4000 km s-1 and β e ~ 0.001-10 suggests that one can predict the magnitude of the bulk electron heating by reconnection in a variety of contexts from the simple knowledge of a single parameter: the Alfvén speed of the ambient plasma.

Keywords: Space plasmas, Geomagnetic fields, Plasma physics, Planetary magnetospheres, Magnetic fields
Evidence of Extended Dust and Feedback around z ≈ 1 Quiescent Galaxies via Millimeter Observations. We use public data from the South Pole Telescope (SPT) and Atacama Cosmology Telescope (ACT) to measure the radial profiles of the thermal Sunyaev-Zel'dovich (tSZ) effect and dust emission around massive quiescent galaxies at z ≈ 1. Using survey data from the Dark Energy Survey and Wide-Field Infrared Survey Explorer, we selected 387,627 quiescent galaxies within the ACT field, with a mean stellar ${\mathrm{log}}_{10}({M}_{\star }/{M}_{\odot })$ of 11.40. A subset of 94,452 galaxies, with a mean stellar ${\mathrm{log}}_{10}({M}_{\star }/{M}_{\odot })$ of 11.36, are also covered by SPT. In $0\buildrel{\,\prime}\over{.} \,5$ bins around these galaxies, we detect the tSZ profile at levels up to 11σ, and dust profile up to 20σ. Both profiles are extended, and the dust profile slope at large radii is consistent with galaxy clustering. We analyze the thermal energy and dust mass versus stellar mass via integration within $R=2\buildrel{\,\prime}\over{.} \,0$ circular apertures and fit them with a forward-modeled power law to correct for our photometric stellar mass uncertainties. At the mean log stellar mass of our Overlap and Wide-Area Samples, respectively, we extract thermal energies from the tSZ of ${E}_{\mathrm{pk}}={6.45}_{-1.52}^{+1.67}\times {10}^{60}\,\mathrm{erg}$ and ${8.20}_{-0.52}^{+0.52}\times {10}^{60}\,\mathrm{erg},$ most consistent with moderate to high levels of active galactic nucleus feedback acting upon the circumgalactic medium. Dust masses at the mean log stellar mass are ${M}_{{\rm{d}},\mathrm{pk}}={6.23}_{-0.67}^{+0.67}\times {10}^{8}\,{M}_{\odot }$ and ${6.76}_{-0.56}^{+0.56}\times {10}^{8}\,{M}_{\odot },$ respectively, and we find a greater than linear dust-to-stellar mass relation, which indicates that the more-massive galaxies in our study retain more dust. Our work highlights the current capabilities of stacking millimeter data around individual galaxies and their potential for future use.

Keywords: Interstellar dust, Large-scale structure of the universe, Quasars, Sunyaev-Zeldovich effect, Galaxy evolution, Intergalactic medium, Cosmic background radiation
Observational Analysis of Lyα Emission in Equivalent-magnitude Solar Flares. The chromospheric Lyα line of neutral hydrogen (1216 Å) is the most intense emission line in the solar spectrum, yet until recently observations of flare-related Lyα emission have been scarce. Here, we examine the relationship between nonthermal electrons accelerated during the impulsive phase of three M3 flares that were co-observed by RHESSI, GOES, and the Solar Dynamics Observatory, and the corresponding response of the chromosphere in Lyα. Despite having identical X-ray magnitudes, these flares showed significantly different Lyα responses. The peak Lyα enhancements above the quiescent background for these flares were 1.5%, 3.3%, and 6.4%. However, the predicted Lyα enhancements from FISM2 were consistently &lt;2.5%. By comparing the properties of the nonthermal electrons derived from spectral analysis of hard X-ray observations, flares with a "harder" spectral index were found to produce a greater Lyα enhancement. The percentage of nonthermal energy radiated by the Lyα line during the impulsive phase was found to range from 2.0% to 7.9%. Comparatively, the radiative losses in He II (304 Å) were found to range from 0.6% to 1.4% of the nonthermal energy while displaying enhancements above the background of 7.3% to 10.8%. FISM2 was also found to underestimate the level of He II emission in two of the three flares. These results may have implications for space weather studies and for modeling the response of the terrestrial atmosphere to changes in the solar irradiance, and will guide the interpretation of flare-related Lyα observations that will become available during Solar Cycle 25.

Keywords: Solar flares, Solar extreme ultraviolet emission, Active sun, Solar physics, Spectroscopy, Solar x-ray flares, Solar chromosphere
The Missing Link: Testing Galactic Chemical Evolution Models with the First Multi-isotopic Abundances in Solar Twin Stars. We present the first isotopic abundances of both 13CO and C18O in solar twin stars and test the results against several galactic chemical evolution (GCE) models with different nucleosynthesis prescriptions. First, we compare M-band spectra from IRTF/iSHELL to synthetic spectra generated from custom solar atmosphere models using the PHOENIX atmosphere code. Next, we compare our calculated abundances to GCE models that consider isotopic yields from massive stars, asymptotic giant branch stars, and fast-rotating stars. The 12C/13C ratios determined for this sample of solar twins are consistent with predictions from the selected GCE models; however, the 16O/18O ratios tentatively contradict these predictions. This project constitutes the first in a stellar chemical abundance series seeking to (1) support the James Webb Space Telescope as it characterizes exoplanet atmospheres, interiors, and biosignatures by providing host star abundances; (2) identify how unexplored stellar abundances reveal the process of galactic chemical evolution and correlate with star formation, interior, age, metallicity, and activity; and (3) provide improved stellar ages using stellar abundance measurements. By measuring elemental and isotopic abundances in a variety of stars, we not only supply refined host star parameters, but also provide the necessary foundations for complementary exoplanet characterization studies-and ultimately contribute to the exploration of galactic, stellar, and planetary origins and evolution.

Keywords: Late-type stars, Isotopic abundances, Solar analogs, Galaxy chemical evolution