Sazuna/UAT_keywords huggingface dataset:
Footprints in the Wind: Probing X-Ray Outflows in NGC 7469 Using Near-infrared Emission Lines. Active galactic nuclei (AGN) winds play an important role in the coevolution of supermassive black holes and their host galaxies, yet their driving mechanisms and impact on star formation remain subjects of active investigation. Critically, the lack of X-ray integral field units currently limits our ability to acquire spatially resolved velocity information in the X-ray regime. However, instead, this can be achieved using the James Webb Space Telescope. As part of an ongoing investigation of the nuclear feedback processes in the nearby luminous AGN NGC 7469, we present an analysis of the kinematics of the X-ray emitting outflows using near-infrared footprint lines such as [Mg VIII] λ3.03 μm. These high-ionization emission lines are associated with the same gas analyzed in the X-ray, and thus can be used to probe the footprint of the X-ray wind's velocity structure and ionization state. Thanks to the wide wavelength range available with JWST we also use nebular (e.g., [S IV] λ10.51 μm) and coronal (e.g., [Ne V] λ14.32 μm) emission lines to offer a comprehensive multiphase view of the outflows. We present mass and kinetic energy outflow rates and find that while the feedback processes in NGC 7469 are not efficient by theoretical benchmarks, the most massive and energetic component is the high ionization X-ray gas.

Keywords: AGN host galaxies, X-ray astronomy, Active galaxies, Infrared astronomy, Active galactic nuclei
Astrometric and Spectroscopic Analysis of IC 2714: An Open Cluster Hosting a Lithium-rich Giant. Open clusters serve as laboratories to study and evaluate stellar evolution and Galactic chemical evolution models. Chemical peculiarities, such as lithium-rich giants, are rarely observed in these stellar systems. This work focuses on eight red giants (#005, #028, #034, #053, #087, #121, #126, and #190) previously reported as members of the Galactic cluster IC 2714. We conducted a detailed investigation using high-resolution spectroscopy, supplemented with data from the Gaia DR3 catalog. Besides deriving the cluster's fundamental parameters, we provide the most thorough chemical characterization of IC 2714 to date, reporting the abundance of 23 species, including light elements (Li, C, N, O), odd-Z elements (Na, Al), α-elements (Si, Ca, Ti, Mg), iron-peak elements (Sc, Cr, Ni), s-process-dominated elements (Y, Zr, Ba, La, Ce, Nd) and r-process elements (Sm, Eu). We also present the carbon isotopic ratios 12C/13C for the first time for seven stars. One particular star (#087) exhibits a high lithium abundance ( log∊ (Li)NLTE = +1.54 dex) and a slightly higher projected rotational velocity ( vsini  = 6.7 km s−1). Our results suggest that the analyzed stars are in the core-helium-burning phase of evolution, where the most lithium-rich giants are found. Combining astrometric probabilities and chemical abundances, we conclude that two giants (#028 and #034) might not be cluster members.

Keywords: Fundamental parameters of stars, Stellar abundances, High resolution spectroscopy, Chemically peculiar giant stars
Spectroscopic and Decade-long Photometric Observations of the Contact Binary V2790 Ori: Evidence for a Brown Dwarf Companion and a Solar-like Magnetic Activity Cycle. We present 22 sets of light curves and one radial velocity curve for the W UMa-type total eclipse contact binary system V2790 Ori, derived by combining all available public photometric data, the photometric data in previous studies, and our own spectroscopic and decade-long photometric observations. Our simultaneous analysis of the light curves and radial velocity curve shows that V2790 Ori is a W-subtype contact binary with a mass ratio of q = 0.322(±0.001) and a shallow contact degree of 14.8(±0.6)%. The orbital period analysis based on 445 eclipsing minima reveals a secular decrease at a rate of  Ṗ=−3.18(±0.75)×10−8daysyr−1 , superimposed with a cyclic variation with an amplitude of A = 8.98(±2.19) × 10−4 days and a period of P3 = 7.44(±0.52) yr. The secular decrease is caused by angular momentum loss via magnetic braking, while the cyclic period variation is explained by the light-travel time effect due to a third body, which is likely to be a brown dwarf. Furthermore, our analysis indicates a mass transfer from the more massive component to the less massive one at a rate of 1.22(±0.29) × 10−8 M⊙ yr−1. A model with a cool spot on each component was adopted to fit the O'Connell effect observed in the light curves. Since the O'Connell effect varies over time, we identified a solar-like magnetic activity cycle with a period of approximately 5.4 yr by analyzing the magnitude difference (∆m) at the two light maxima and the O'Connell effect ratio. In addition, evolutionary analysis suggests that V2790 Ori is a newly formed contact binary that evolved from a detached phase into the present contact configuration.

Keywords: Fundamental parameters of stars, W Ursae Majoris variable stars, Close binary stars, Stellar activity, Eclipsing binary stars, Stellar evolution
UV Spectral Slope and Nebular Dust Attenuation in Dwarf Galaxies at 1.4 &lt; z &lt; 2.6. We analyze nebular dust attenuation and its correlation with stellar mass (M*) and ultraviolet (UV) spectral slope (β) in 33 lensed, low-mass star-forming galaxies at 1.4 ≤ z ≤ 2.6, using Keck/Multi-Object Spectrometer For IR Exploration (MOSFIRE) rest-frame optical spectroscopy. Located behind three massive lensing galaxy clusters A1689, MACS J1149.5+2223, and MACS J0717.5+3745, galaxies in our sample have a median stellar mass of  log(M*/M⊙)=8.3  and an intrinsic UV absolute magnitude range of −20.9 &lt; MUV &lt; −13. We measure nebular dust attenuation via Balmer optical depth (τB), defined as the Hα/Hβ ratio. We also derive physical properties from Hubble Space Telescope multiwavelength photometry and construct composite spectra using median stacking in bins of M* and β. We find that the τB─β relation for the dwarf galaxies in this study is best represented by the SMC dust curve. This is consistent with previous studies of low-metallicity galaxies at similar redshifts, which show a steep attenuation curve similar to the SMC curve, in contrast to high-metallicity and more massive galaxies that exhibit a much shallower dust attenuation curve. We also investigate the relationship between nebular dust attenuation and stellar mass, E(B − V)nebular − M*, down to  log(M*/M⊙)∼7 . We demonstrate that this relation does not notably evolve with redshift and is consistent with what has been observed for local Sloan Digital Sky Survey (SDSS) galaxies at similar low stellar masses.

Keywords: Dwarf galaxies, Interstellar dust extinction, High-redshift galaxy clusters
Radiation-driven Destruction of N-heterocycles in the Presence and Absence of Water Ice. Simple N-heterocycles are expected to be an abundant class of molecules within the interstellar medium, and increasingly complex heterocycles (e.g., nucleobases) have been detected within meteoritic organic material and in samples returned from the carbonaceous asteroid Bennu. Despite this, these molecules have not been detected in any interstellar environment or in the outer solar system. One possible reason for the nondetection of N-heterocycles could be that they are less stable to radiation than the aromatic compounds that have been identified in space (e.g., benzene). Here, we present the radiolytic destruction kinetics of benzene and several N-heterocycles, both as single-component ices and as dilute water-ice mixtures at 15 K, where we have quantified the radiolytic destruction rate constants and radiolytic half-lives of these aromatic molecules using IR spectroscopy. We found that the destruction rate constants for single-component ices, and to a lesser extent for water-ice mixtures, depended on the number of nitrogen atoms in the aromatic ring. Our radiolytic half-lives indicate that these molecules should persist in extraterrestrial radiation environments, and radiolytic destruction cannot fully explain the nondetections of N-heterocycles.

Keywords: Cosmic rays, Laboratory astrophysics, Reaction rates, Astrochemistry
JWST's PEARLS: A Candidate Massive Binary Star System in a Lensed Galaxy at Redshift 0.94. Massive stars at cosmological distances can be individually detected during transient microlensing events, when gravitational lensing magnifications may exceed μ ≍ 1000. Nine such sources were identified in JWST NIRCam imaging of a single galaxy at redshift z = 0.94 known as the "Warhol arc," which is mirror imaged by the galaxy cluster MACS J0416.1−2403. Here we present the discovery of two coincident and well-characterized microlensing events at the same location followed by a third event observed in a single filter approximately 18 months later. The events can be explained by microlensing of a binary star system consisting of a red supergiant (T ≍ 4000 K) and a B-type (T ≳ 13,000 K) companion star. The timescale of the coincident microlensing events constrains the estimated projected source-plane size to tens of astronomical units. The most likely binary configurations consistent with the observational constraints on the temperature and luminosity of each star are stars with initial masses  M1init=23.6−4.3+5.3  M⊙ and an initial mass ratio between the two stars close to unity. A kinematic model that reproduces the observed light curves in all filters gives a relatively small transverse velocity of ∼50 km s−1. This requires the dominant velocity component of several hundreds of kilometers per second to be roughly parallel to the microcaustic. An alternative possibility would be that the three microlensing events correspond to unrelated stars crossing distinct microcaustics, but this would imply a highly elevated rate of events at their common position, even though no underlying knot is present at the location.

Keywords: Stellar populations, Massive stars, Gravitational lensing, Binary stars
High-fidelity 3D Reconstruction of Solar Coronal Physics with the Updated CROBAR Method. We present an extension of the Coronal Reconstruction Onto B-Aligned Regions (CROBAR) method to Linear Force Free Field (LFFF) extrapolations, and apply it to the reconstruction of a set of Atmospheric Imaging Assembly, Michelson Doppler Imager, and STEREO EUVI data. The results demonstrate that CROBAR is not only capable of reconstructing coronal emission structures, but also the previously made claim that it can constrain coronal field extrapolations, in this case the LFFF's α parameter. They also provide a real-world example of how CROBAR can easily incorporate information from multiple perspectives to improve its reconstructions, and we also use the additional perspectives to help validate the reconstructions. We furthermore touch on the use of real-world emission passbands rather than idealized power-law type ones using differential emission measures (DEMs). We conclude with a comparison of CROBAR-generated emission to observed emission and those produced with idealized DEM based power laws. These results further illustrate the promise of CROBAR for real-world applications, and we make available a preliminary release of the software available for download.

Keywords: Solar extreme ultraviolet emission, Solar coronal loops, Astronomy data analysis, Solar x-ray emission, Computational methods, Solar corona, Solar magnetic fields, Active solar corona
A Study Revealing the Physical Attributes of the Supernova Remnant in G321.3─3.9. We present a radio analysis of the recently identified supernova remnant G321.3─3.9 using archival multiwavelength data spanning 88─2304 MHz. The source exhibits an elliptical shell-like morphology (1 .° 3 × 1 .° 7) and a relatively flat nonthermal spectral index of α = −0.40 ± 0.03. The distance is estimated using both the Σ─D relation (1.6─2.9 kpc) and tentative associations with H I structures, the latter suggesting a near-side solution of 2.5─3.3 kpc, though the physical connection remains uncertain.

Keywords: Supernova remnants, Interstellar medium, Nebulae
The Centennial Evolution of Solar Chromospheric Rotation. Rotation is a prominent feature of the Sun, and it plays a crucial role in the generation and dynamic evolution of solar magnetic fields. The daily composite time series of Ca II K plage areas from 1907 February 1 to 2023 December 31 is used to analyze its periodicity and examine the temporal variation of its rotation period lengths (RPLs) using continuous wavelet transform. Wavelet analysis reveals that over a time span of more than a century, chromospheric rotation exhibits a dominant synodic period of approximately 26.62 days, with complex temporal variations. The long-term trend of chromospheric rotation is well-characterized by a statistically significant quadratic polynomial, showing a gradual deceleration from solar cycles 15 to 19, followed by a gradual acceleration from cycles 19 to 24. The RPLs exhibit a negative correlation between the rotation rate of the chromosphere and solar magnetic activity. Their behavior follows a distinct pattern within a Schwabe cycle: the rotation period progressively lengthens during the initial approximately 3 yr, then maintains a relatively long value from year 3 to approximately 7.5, and finally shortens during the declining phase, returning to a minimum near the subsequent solar minimum. The variations of chromospheric RPLs show significant periods of 3.2, 5.7, 7.7, 10.3, and 12.3 yr, with cross-correlation analysis pointing to a complex relationship with solar activity. The possible mechanisms for the temporal variation of the chromospheric rotation are discussed.

Keywords: Solar rotation, Stellar magnetic fields
Deuterium Fractionation and CO Depletion in Barnard 5. Deuterium fractionation provides a key diagnostic of the physical and chemical evolution of prestellar and protostellar cores, where it is strongly linked to CO depletion in cold, dense gas. We present the first spatially resolved maps of deuterium fraction and CO depletion in the Barnard 5 region of the Perseus molecular cloud, covering both a starless core and the protostellar core hosting the Class 0/I source IRAS 03445+3242. Using IRAM 30 m observations of N2H+(1─0), N2D+(1─0), H13CO+(1─0), and DCO+(2─1), complemented by C18O(2─1) data, we derive column density, deuterium fraction, and CO depletion maps. We find that the deuterium fraction in the abovementioned nitrogen- and carbon-bearing species increases from the protostellar to the starless core, reaching  RDN2H+=0.43±0.10  and  RDHCO+=0.09±0.02  in the starless core, compared with 0.15 ± 0.03 and 0.05 ± 0.01, respectively, in the protostellar core. The CO depletion factor also rises from 4.1 ± 0.1 to 5.0 ± 0.1 across the same transition. While the embedded young stellar object reduces deuteration in the dense inner gas, the less dense envelope traced by HCO+ is only slightly affected at our resolution. Our analysis confirms that CO freeze-out and the presence of a protostar jointly regulate deuterium chemistry in star-forming regions.

Keywords: Radio spectroscopy, Interstellar filaments, Star forming regions, Chemical abundances, Astrochemistry, Interstellar clouds
Polka-dotted Stars. II. Starspots and Obliquities of Kepler-17 and Kepler-63. Starspots trace stellar magnetic activity and affect both stellar evolution and exoplanet characterization. While occultation-based spot studies have been applied to individual systems, comparative analyses remain limited. We apply the StarryStarryProcess Bayesian surface mapping framework to archival Kepler light curves of two planet hosts—Kepler-63 and Kepler-17—extending the validation established on TOI-3884 (Paper I). Across both systems, we infer characteristic spot radii of &lt;10∘. The latitudinal distributions of both G-dwarfs exhibit active latitudes (Kepler-63 at ±30∘, Kepler-17 at ±15∘). Our analysis yields stellar obliquity measurements in excellent agreement with previous studies for both systems. This validates our methodology and demonstrates that transit-based surface mapping can simultaneously recover planetary parameters, stellar orientations, and magnetic morphologies. The analysis of the systems inferred nearly aligned (Kepler-17) to highly misaligned (Kepler-63) geometries.

Keywords: Starspots, Orbits, Astronomy data analysis, Exoplanet astronomy, Gaussian Processes regression
Extremely Energetic Extreme-ultraviolet Late Phase of a Pair of C-class Flares Caused by a Noneruptive Sigmoid. The extreme-ultraviolet (EUV) late phase (ELP) is the second increase of the irradiance of warm coronal lines during solar flares, and has a crucial impact on the Earth's ionosphere. In this paper, we report on the extremely energetic ELP of a pair of C-class flares (SOL2012-06-17T17:26:11) observed on 2012 June 17 in NOAA active region 11504 by the Atmospheric Imaging Assembly (AIA) instrument on board the Solar Dynamics Observatory. The light curves integrated over the flaring region show that a factor of 4.2 more energy is released in the "warm-temperature" (2─3 × 106 K) passbands (e.g., AIA 335 Å) during the late phase than during the main peaks. The origin of the emission in this extremely energetic ELP is a noneruptive sigmoid situated in a multipolar magnetic field configuration, which is rapidly energized by C-class flares. The sigmoid plasma appears to reach temperatures in excess of 107 K, before cooling to produce the ELP emission. This is seen in high-temperature passbands (e.g., AIA 131 Å) and by using differential emission measure analysis. Magnetic extrapolations indicate that the sigmoid is consistent with formation by magnetic reconnection between previously existing J-shaped loops. The sigmoid experienced fast and slow cooling stages, both of which were dominated by conductive cooling. The estimated total cooling time of the sigmoid is shorter than the observed value. So, we proposed that the noneruptive sigmoid, heated by continuous magnetic reconnection, leads to the extremely energetic ELP.

Keywords: Solar flares, Solar extreme ultraviolet emission
Discovery of High X-Ray Polarization from the Neutron Star Low-mass X-Ray Binary Cyg X-2 on the Horizontal Branch. We present results from simultaneous X-ray polarimetric and spectroscopic observations of the bright neutron star low-mass X-ray binary Cyg X-2, performed by the Imaging X-ray Polarimetry Explorer (IXPE) and the Nuclear Spectroscopic Telescope Array. IXPE detected significant polarization (15σ) from the source in the 2─8 keV energy band with an average polarization degree (PD) of 4.5% ± 0.3% and a polarization angle (PA) of 128° ± 2° as the source moved along the horizontal branch of its Z-track. The PD increases with energy reaching 9.9% ± 2.8% in the 7─8 keV band, with no evidence for energy-dependent variation in the PA. The PA is roughly consistent with previous measurements obtained during the normal and flaring branches and also with the known radio jet axis. From spectropolarimetric analysis, the main contribution to the polarized radiation is due to Comptonized photons, but the polarization is higher than predicted in typical spreading layer geometries. The observed high polarization may be due to a combination of a highly polarized reflected component and a moderately polarized spreading layer on the neutron star surface or produced by electron scattering in an equatorial wind.

Keywords: Neutron stars, Accretion, Spectropolarimetry, Low-mass x-ray binary stars, Polarimetry
Investigating the Active Galactic Nuclei Variability Timescale─Black Hole Mass Relationship with Gaia, SDSS, and ZTF. Active galactic nuclei (AGNs) exhibit variability in their luminosities with timescales that correlate with the mass of the black hole at the centre of the AGN. Presently, the empirical correlation lacks sufficient precision to confidently convert these timescales into black hole masses, especially at the low-mass end. To find more AGNs with timescale measurements, we study a very large catalog of AGNs from Data Release 3 of Gaia, called Gaia variabLE AgN (GLEAN, with 872,228 objects). We identify GLEAN objects with optical spectra from the Sloan Digital Sky Survey Data Release 17 and light curves from the Zwicky Transient Facility (ZTF) Data Release 21. After fitting the light curves with a damped random walk (DRW) model, we find that the GLEAN light curves have insufficient sampling to extract reliable amplitude and timescale measurements outside the range of 50─100 days. On the other hand, well-sampled ZTF light curves allow more accurate estimations of these parameters. The fractional variability amplitude is an effective, model-independent metric for measuring variability amplitude, but only when derived from high-quality light curves. We provide a catalog of 127 GLEAN AGNs with spectroscopic virial black hole masses, and variability amplitudes and timescales. Though we do not find any low-mass black holes in this AGN sample, we confirm a relationship between the DRW timescale and the black hole mass that is consistent with previous studies.

Keywords: Supermassive black holes, Active galactic nuclei, Gaia
SMILES Data Release. II. Probing Galaxy Evolution during Cosmic Noon and Beyond with NIRSpec Medium-resolution Spectra. We present the second data release of the Systematic Mid-Infrared Instrument Legacy Extragalactic Survey (SMILES), focusing on JWST/NIRSpec medium-resolution spectroscopy of galaxies across cosmic time. This release includes spectroscopic observations of 166 galaxies spanning 0 &lt; z &lt; 7.5, sampling star-forming galaxies, quiescent systems, and active galactic nuclei (AGNs), with an emphasis on galaxies at cosmic noon (z ∼ 1─3). We describe the target selection strategy, the observational setup with the G140M/F100LP and G235M/F170LP gratings, and the data calibration process. The final data products include the reduced spectra, redshift catalog, emission-line catalogs produced with GELATO for emission-line galaxies and pPXF fits for quiescent systems, and ancillary spectral energy distribution fit results derived from multiband photometry. The SMILES NIRSpec dataset enables investigations of obscured AGNs, multiphase outflows, ionizing properties, and the role of environment in galaxy evolution. All data products are publicly available through STScI/MAST at https://archive.stsci.edu/hlsp/smiles.

Keywords: Active galactic nuclei, Galaxy spectroscopy, High-redshift galaxies
Flare Activity and Magnetic Feature Analysis of the Flare Stars. III. K-type Dwarf Binary Components. We analyze the light curve of 199 dwarf stars that are members of binary systems resolved by Kepler mission. All of them are K-type active stars in binary systems of which their flare activity has been confirmed. From the light-curve modulation, we can infer stability, relative coverage, and contrast of the magnetic structures. In addition, we extract the flare component from the light-curve fluctuations and study the flare characteristics such as total time duration, power, and flux magnitude. These magnetic activity indicators show the same dependency to the Rossby number such as single main-sequence (MS) stars and have the same saturation or supersaturation behavior at high rotation rates. Also, while the average rotation period of the binary sample is much lower than single MS and subgiant branch (SGB), their flare activity level is just slightly higher than the single MS and is lower than the single SGB stars. This shows that the production of magnetic fields through a dynamo procedure is more affected by the convective depth rather than the rotation period. Furthermore, the presence of the companion star and spinning up of the rotation period has a greater effect on the relative coverage and contrast of the magnetic features than the flare activity.

Keywords: Starspots, Magnetic stars, Stellar activity, Flare stars, Stellar rotation, Magnetic fields