Sazuna/UAT_keywords huggingface dataset:
Detection of the White Dwarf Spin of the Long-orbital Period Magnetic Cataclysmic Variable V1082 Sgr. We report on the discovery of circular polarization modulated with a period of 1.943 ± 0.002 hr in the cataclysmic variable V1082 Sgr. These findings unambiguously reveal the rotation of a magnetic white dwarf and establish its intermediate polar nature. Along with its extraordinary long orbital period (Porb) of 20.8 hr, the spin period (Pspin) places this system in an extreme position of the Pspin versus Porb distribution. The circular polarization phase diagram has a single peak and an amplitude smaller than 1%. These data were used to model the postshock region of the accretion flow on the white dwarf surface using the CYCLOPS code. We obtained a magnetic field in the white dwarf pole of 11 MG and a magnetospheric radius consistent with the coupling region at around 2–3 white dwarf radii. The Pspin/Porb value and the estimated magnetic field momentum suggest that V1082 Sgr could be out of spin equilibrium or in a spin-up state, possibly in a stream accretion mode.

Keywords: Close binary stars, White dwarf stars, Stellar magnetic fields, Starlight polarization, Stellar accretion, Cataclysmic variable stars
On the Uniqueness and Causal Relationship of Precursor Activity to Solar Energetic Events. I. Transient Brightenings—Introduction and Overview. The physical role played by small-scale activity that occurs before the sudden onset of solar energetic events (SEEs, i.e., solar flares and coronal mass ejections) remains in question, in particular as related to SEE initiation and early evolution. It is still unclear whether such precursor activity, often interpreted as plasma heating, particle acceleration, or early filament activation, is indicative of a pre-event phase or simply ongoing background activity. In this series, we statistically investigate the uniqueness and causal connection between precursors and SEEs using paired activity-quiet epochs. This first paper specifically introduces transient brightenings (TBs) and presents analysis regimes to study their role as precursors, including imaging of the solar atmosphere, magnetic field, and topology analysis. Applying these methods qualitatively to three cases, we find that, prior to solar flares, TBs (1) tend to occur in one large cluster close to the future flare ribbon location and below the separatrix surface of a coronal magnetic null point, (2) are cospatial with reconnection signatures in the lower solar atmosphere, such as bald patches and null-point fan traces, and (3) cluster in the vicinity of strong-gradient polarity inversion lines and regions of increased excess magnetic energy density. TBs are also observed during quiet epochs of the same active regions, but they appear in smaller clusters not following a clear spatial pattern, although sometimes associated with short, spatially intermittent bald patches and fan traces, but predominantly away from strong-gradient polarity inversion lines in areas with little excess energy density.

Keywords: Solar activity, Solar flares, Solar coronal mass ejections
Irregularly Sampled Time Series Interpolation for Detailed Binary Evolution Simulations. Modeling of large populations of binary stellar systems is an integral part of many areas of astrophysics, from radio pulsars and supernovae to X-ray binaries, gamma-ray bursts, and gravitational-wave mergers. Binary population synthesis codes that employ self-consistently the most advanced physics treatment available for stellar interiors and their evolution and are at the same time computationally tractable have started to emerge only recently. One element that is still missing from these codes is the ability to generate the complete time evolution of binaries with arbitrary initial conditions using precomputed three-dimensional grids of binary sequences. Here, we present a highly interpretable method, from binary evolution track interpolation. Our method implements simulation generation from irregularly sampled time series. Our results indicate that this method is appropriate for applications within binary population synthesis and computational astrophysics with time-dependent simulations in general. Furthermore, we point out and offer solutions to the difficulty surrounding evaluating the performance of signals exhibiting extreme morphologies akin to discontinuities.

Keywords: Interdisciplinary astronomy, Computational methods, Stellar evolutionary tracks, Binary stars
Chandra Detects Low-luminosity Active Galactic Nucleus with M<SUB>BH</SUB> = 10<SUP>4</SUP>–10<SUP>6</SUP> M<SUB>⊙</SUB> in Nearby (z &lt; 0.5) Dwarf and Star-forming Galaxies. We searched the Chandra and XMM archives for 900 Green Pea galaxies to identify signs of active galactic nuclei (AGN). Green peas are low-mass, emission-line galaxies that resemble high-redshift dwarf galaxies. From 29 observations, we detected X-rays in nine galaxies with signal-to-noise ratio &gt; 3. These X-ray sources also show He II and broad Hα emissions, suggesting winds, though the weak correlation between their line widths implies that the He II emission is not from super-Eddington accretors. The ratio of X-ray luminosity to star formation rate aligns with an anticorrelation with metallicity for most detected sources, pointing to ultraluminous X-ray sources as likely contributors. The X-ray emission exceeds what stellar processes can produce, supporting the existence of low-luminosity AGN. Using the broad Hα emission lines, we infer black hole masses ranging from 104 to 106 M⊙ in these sources. Since Green Peas are significant Lyman continuum leakers, these AGN may have played a role in cosmic reionization.

Keywords: AGN host galaxies, Reionization, Dwarf galaxies, Black holes
3D CMZ. I. Central Molecular Zone Overview. The Central Molecular Zone (CMZ) is the largest reservoir of dense molecular gas in the Galaxy and is heavily obscured in the optical and near-IR. We present an overview of the far-IR dust continuum, where the molecular clouds are revealed, provided by Herschel in the inner 40° (∣l∣ &lt; 20°) of the Milky Way with a particular focus on the CMZ. We report a total dense gas (N(H2) &gt; 1023 cm‑2) CMZ mass of   M⊙ and confirm that there is a highly asymmetric distribution of dense gas, with about 70%–75% at positive longitudes. We create and publicly release complete fore/background-subtracted column density and dust temperature maps in the inner 40° (∣l∣ &lt; 20°) of the Galaxy. We find that the CMZ clearly stands out as a distinct structure, with an average mass per longitude that is at least 3× higher than the rest of the inner Galaxy contiguously from 1 8 &gt; ℓ &gt; ‑1 3. This CMZ extent is larger than previously assumed, but is consistent with constraints from velocity information. The inner Galaxy's column density peaks towards the SgrB2 complex with a value of about 2 × 1024 cm‑2, and typical CMZ molecular clouds are about N(H2) ∼ 1023 cm‑2. Typical CMZ dust temperatures range from ∼12–35 K with relatively little variation. We identify a ridge of warm dust in the inner CMZ that potentially traces the base of the northern Galactic outflow seen with MEERKAT.

Keywords: Dust continuum emission, Galactic center, Star formation, Far infrared astronomy
3D CMZ. II. Hierarchical Structure Analysis of the Central Molecular Zone. The Central Molecular Zone (CMZ) is the way station at the heart of our Milky Way Galaxy, connecting gas flowing in from Galactic scales with the central nucleus. Key open questions remain about its 3D structure, star formation properties, and role in regulating this gas inflow. In this work, we identify a hierarchy of discrete structures in the CMZ using column density maps from Paper I (C. Battersby et al.) We calculate the physical (N(H2), Tdust, mass, radius) and kinematic (HNCO, HCN, and HC3N moments) properties of each structure as well as their bolometric luminosities and star formation rates. We compare these properties with regions in the Milky Way disk and external galaxies. Despite the fact that the CMZ overall is well below the Gao-Solomon dense gas star formation relation (and in modest agreement with the Schmidt–Kennicutt relation), individual structures on the scale of molecular clouds generally follow these star formation relations and agree well with other Milky Way and extragalactic regions. We find that individual CMZ structures require a large external pressure (Pe/kB &gt; 107‑9 K cm‑3) to be considered bound; however, simple estimates suggest that most CMZ molecular-cloud-sized structures are consistent with being in pressure-bounded virial equilibrium. We perform power-law fits to the column density probability distribution functions of the inner 100 pc, SgrB2, and the outer 100 pc of the CMZ as well as several individual molecular cloud structures and find generally steeper power-law slopes (‑9 &lt; α &lt; ‑2) compared with the literature (‑6 &lt; α &lt; ‑1).

Keywords: Galactic center, Star formation, Molecular clouds
3D CMZ. III. Constraining the 3D Structure of the Central Molecular Zone via Molecular Line Emission and Absorption. The Milky Way's Central Molecular Zone (CMZ) is the largest concentration of dense molecular gas in the Galaxy, the structure of which is shaped by the complex interplay between Galactic-scale dynamics and extreme physical conditions. Understanding the 3D geometry of this gas is crucial, as it determines the locations of star formation and subsequent feedback. We present a catalog of clouds in the CMZ using Herschel data. Using archival data from the APEX and MOPRA CMZ surveys, we measure averaged kinematic properties of the clouds at 1 and 3 mm. We use archival ATCA data of the H2CO (11,0─11,1) 4.8 GHz line to search for absorption towards the clouds, and 4.85 GHz Green Bank Telescope (GBT) C-band data to measure the radio continuum emission. We measure the absorption against the continuum to provide new constraints for the line-of-sight positions of the clouds relative to the Galactic Center, and find a highly asymmetric distribution, with most clouds residing in front of the Galactic Center. The results are compared with different orbital models, and we introduce a revised toy model of a vertically oscillating closed elliptical orbit. We find that most models describe the position─position─velocity structure of the gas reasonably well, but find significant inconsistencies in all cases regarding the near versus far placement of individual clouds. Our results highlight that the CMZ is likely more complex than can be captured by these simple geometric models, along with the need for new data to provide further constraints on the true 3D structure of the CMZ.

Keywords: Galactic center, Molecular clouds
3D CMZ. IV. Distinguishing Near versus Far Distances in the Galactic Center Using Spitzer and Herschel. A comprehensive 3D model of the central 300 pc of the Milky Way, the Central Molecular Zone (CMZ) is of fundamental importance in understanding energy cycles in galactic nuclei, since the 3D structure influences the location and intensity of star formation, feedback, and black hole accretion. Current observational constraints are insufficient to distinguish between existing 3D models. Dust extinction is one diagnostic tool that can help determine the location of dark molecular clouds relative to the bright Galactic Center emission. By combining Herschel and Spitzer observations, we developed three new dust extinction techniques to estimate the likely near/far locations for each cloud in the CMZ. We compare our results to four geometric CMZ orbital models. Our extinction methods show good agreement with each other, and with results from spectral line absorption analysis from Walker et al. Our near/far results for CMZ clouds are inconsistent with a projected version of the Y. Sofue two-spiral-arms model, and show disagreement in position–velocity space with the S. Molinari et al. closed elliptical orbit. Our results are in reasonable agreement with the J. M. D. Kruijssen et al. open streams. We find that a simplified toy-model elliptical orbit that conserves angular momentum shows promising fits in both position–position and position–velocity space. We conclude that all current CMZ orbital models lack the complexity needed to describe the motion of gas in the CMZ, and further work is needed to construct a complex orbital model to accurately describe gas flows in the CMZ.

Keywords: Galactic center, Interstellar dust extinction, Infrared dark clouds
SN 2021hpr: A Normal Type Ia Supernova Showing Excess Emission in the Early Rising Phase. We present extensive optical observations of a nearby Type Ia supernova (SN Ia), SN 2021hpr, located in the spiral galaxy NGC 3147 at a distance of ∼45 Mpc. Our observations cover a phase within ∼1–2 days to ∼290 days after the explosion. SN 2021hpr is found to be a spectroscopically normal SN Ia, with an absolute B-band peak magnitude of   mag and a postpeak decline rate of Δm15(B) = 1.0 ± 0.01 mag. Early time light curves showed a ∼7.0% excess emission compared to a homogeneously expanding fireball model, likely due to SN ejecta interacting with a companion or immediate circumstellar matter (CSM). The optical spectra of SN 2021hpr are overall similar to those of normal SNe Ia, but characterized by prominent detached high-velocity features (HVFs) of Si II and Ca II in the early phase. After examining a small sample of well-observed normal SNe Ia, we find that the HVFs are likely common for the subgroup with early excess emission. The association of an early bump feature with the HVFs could be attributed to density or abundance enhancement at the outer layer of the exploding star, likely as a result of interactions with companion/CSM or experiencing more complete burning. Nevertheless, the redshifted Fe II and Ni II lines in the nebular-phase spectra of SN 2021hpr, contrary to the blueshift trend seen in other SNe Ia showing early bump features, indicate its peculiarity in the explosion that remains to be understood.

Keywords: Type Ia supernovae, Supernovae
The Gaseous Blowout of the 30 Doradus Starburst Region in the LMC. Widespread galactic winds emanate from the Large Magellanic Cloud (LMC), with the 30 Doradus starburst region generating the fastest and most concentrated gas flows. We report on the gas distribution, kinematics, and ionization conditions of the near-side outflow along eight down-the-barrel sightlines using UV absorption-line observations from the Hubble Space Telescope's Ultraviolet Legacy Library of Young Stars as Essential Standards (ULLYSES) program for this region along with H I 21 cm observations from the Parkes Galactic All-Sky Survey (GASS) and Galactic Australian Square Kilometre Array Pathfinder (GASKAP) survey. We find that within Δθ ≲ 1 7 from the center of 30 Doradus, the wind reaches maximum speeds of 100–150 km s‑1 from the LMC's disk. The total integrated column densities of low ions (O I, Si II, and Fe II) in the blueshifted wind, up to vLSR = 150 km s‑1, are highest near the center and decline radially outward. We estimate an outflow mass of Moutflow, Si II ≈ (5.7–8.6) × 105M⊙, outflow rate of  , and mass loading factor of η ≳ 0.10 within Δθ ≲ 0 52 from the center of 30 Doradus. The observed ion ratios—together with photoionization modeling—reveal that this wind is roughly 40%–97% photoionized. The metallicities and dust depletion patterns of the high-velocity absorbers at vLSR ≈ +120 km s‑1 can be explained by either a foreground Milky Way (MW) halo cloud or an outflow from the LMC. For the high ions, Si IV and C IV are broader and kinematically offset from the low ions, suggesting turbulent mixing layers existing in the wind. Finally, our hydrodynamical simulations of the Magellanic Clouds and MW system suggest that the Magellanic Corona can protect the LMC winds from the ram pressure forces exerted by the MW's halo.

Keywords: Galactic winds, Large Magellanic Cloud, Circumgalactic medium
oMEGACat. V. Helium Enrichment in ω Centauri as a Function of Metallicity. Constraining the helium enhancement in stars is critical for understanding the formation mechanisms of multiple populations in star clusters. However, measuring helium variations for many stars within a cluster remains observationally challenging. We use Hubble Space Telescope photometry combined with MUSE spectroscopic data for over 7200 red giant branch stars in ωCen to measure helium differences between distinct groups of stars as a function of metallicity, separating the impact of helium enhancements from other abundance variations on the pseudo-color (chromosome) diagram. Our results show that stars at all metallicities have subpopulations with significant helium enhancement (∆Ymin ≳ 0.11). We find a rapid increase in helium enhancement across low metallicities ([Fe/H] ≃ −2.05 to [Fe/H] ≃ −1.92), with this enhancement leveling out at ∆Y = 0.15 at higher metallicities. The fraction of helium-enhanced stars steadily increases with metallicity from 10% at [Fe/H] ≃ −2.04 to over 90% at [Fe/H] ≃ −1.04. From these measurements, we calculate the total mass in helium produced over the cluster's lifetime, finding  . This study is the first to examine helium enhancement across the full range of metallicities in ωCen, providing new insight into its formation history and additional constraints on enrichment mechanisms.

Keywords: Globular star clusters, Helium-rich stars, Stellar populations, Galactic archaeology, Stellar astronomy, Star clusters
The LUNIS-AGN Catalog: Trends of Emission Line Velocity Dispersion and Surface Brightness within the Circumnuclear Regions of Seyfert Galaxies. We present the Local Universe Near-Infrared Seyfert catalog of K-band integral field unit data of 88 nearby active galactic nuclei (AGN), curated from SINFONI/Very Large Telescope and OSIRIS/Keck archival data sets. This catalog includes both type 1 and type 2 Seyfert AGN probed down to scales of tens of parsecs with z &lt; 0.02 and spanning over 5 orders of magnitude in L14−195 keV AGN luminosity. As part of this catalog, we make publicly available for all galaxies the processed data cubes, a central 200 pc integrated spectrum, and two-dimensional maps of flux, velocity, and velocity dispersion for H2 1-0 S(1) 2.1218 μm, [Si VI] 1.9641 μm, and Br-γ 2.1655 μm. The morphology and geometry of [Si VI], a tracer of AGN outflows, are reported for the 66% of galaxies with extended emission. We utilize this large sample to probe the behavior of molecular and ionized gas, identifying trends in the properties of the circumnuclear gas (surface brightness and velocity dispersion) with fundamental AGN properties (obscuration and X-ray luminosity). While there is significant variation in circumnuclear gas characteristics across the sample, we find molecular hydrogen to be less centrally concentrated and to exhibit lower velocity dispersion relative to ionized gas. In addition, we find elevated molecular hydrogen surface brightness and decreased [Si VI] velocity dispersion in obscured relative to unobscured AGN. The [Si VI] and Br-γ emission scale with L14−195 keV X-ray luminosity, which, along with the elevated velocity dispersion compared to the molecular gas, verifies an association with AGN outflow processes.

Keywords: Seyfert galaxies, Active galactic nuclei
Multi-height Study of the Chromospheric Inverse Evershed Flow and its Association with Photospheric Flows. We analyzed the inverse Evershed flow (IEF) around a sunspot (NOAA 13131) using line scan observations in the Fe I 6173 Å and Ca II 8542 Å spectral lines, complemented with data products from the Solar Dynamics Observatory's Helioseismic and Magnetic Imager. Line-of-sight (LOS) velocities were obtained for different bisector levels in both spectral lines. Additionally, the Ca II 8542 Å spectra were inverted using the Non-LTE Inversion COde using the Lorien Engine (or NICOLE) to retrieve the temperature and velocity stratification over different layers of the lower solar atmosphere. The IEF evolved dynamically in time and with height in the solar atmosphere. The flow speed associated with the IEF channels was on the order of 8 km s‑1 in the upper chromosphere, which decreased in the lower layers of the atmosphere. The flow was traced to the lower chromosphere in LOS velocity maps and the upper photosphere in intensity images. The temperature enhancements associated with the IEF were up to 300 K at log τ ≈ ‑2 and 800 K at log τ ≈ ‑6 near the end point of one channel. The overall appearance of the flow along the IEF channels seems consistent with a siphon flow model. We investigated the association of the IEF with the photospheric Evershed flow, but no obvious connection was found in our analysis. We also analyzed the effect of the IEF on moving magnetic features (MMF) selected near and away from IEF channels. MMFs moved radially outward with velocities in the 0.2–1 km s‑1 range, with no apparent association with the IEF.

Keywords: Solar photosphere, Sunspots, Sunspot flow, Solar chromosphere
Diverse Dust Populations in the Near-Sun Environment Characterized by PSP/ISʘIS. The Integrated Science Investigation of the Sun energetic particle instrument suite on the Parker Solar Probe is dedicated to measuring energetic ions and electrons in the near-Sun environment. It includes a half-sky-viewing time-of-flight mass spectrometer (EPI-Lo) and five high-energy silicon solid-state detector-telescopes (EPI-Hi). To 2024 August, eight of EPI-Lo's eighty separate telescope foils have experienced direct dust puncture events, most of which occurred inside 40 solar radii (0.19 au). These impacts represent the closest high-fidelity dust detections to the Sun. While there is limited information about the size/mass of each impact due to the lack of a dedicated dust instrument, we can determine the impact direction for six punctures, allowing us to partially constrain abundant dust populations in the inner zodiacal cloud. Remarkably, one of six unambiguous dust impactors was likely on a retrograde orbit, suggesting long-period cometary material may survive within 20 solar radii (0.09 au). We discuss observations in the context of highlighting multiple dust populations responsible for these events to improve our understanding of the zodiacal dust environment in the inner heliosphere ( 1 au).

Keywords: Zodiacal cloud, Interplanetary dust, Meteoroids
Upper Limits to the Proper Motions of JuMBO 24, a Jupiter-mass Binary Object Candidate in Orion. Using JWST near-infrared data of the inner Orion Nebula, S. G. Pearson &amp; M. J. McCaughrean detected 40 binary systems they proposed to be Jupiter-mass binary objects (JuMBOs)—although their actual nature is still in debate. Only one of the objects, JuMBO 24, was detected in the radio continuum. Here, we report on new radio continuum (10 GHz) Karl G. Jansky Very Large Array (VLA) detections of the radio counterpart to JuMBO 24, and on an unsuccessful search for 5 GHz continuum emission with the High Sensitivity Array (HSA). From our new VLA detections and adopting a distance to the region, we set an upper limit of ≃6 km s‑1 to the velocity of the radio source in the plane of the sky. This upper limit favors an origin for this source similar to that of stars, that is, from a stationary contracting core. The nature of the radio emission remains uncertain, but the lack of strong variability (all VLA observations are consistent with a steady flux of ∼50 μJy), of detection on long HSA baselines, and of detectable circular polarization in VLA data do not favor a nonthermal origin.

Keywords: Exoplanets