Sazuna/UAT_keywords huggingface dataset:
The Small Separation A-star Companion Population: Tentative Signatures of Enhanced Multiplicity with Primary Mass. We present updated results from our near-infrared long-baseline interferometry (LBI) survey to constrain the multiplicity properties of intermediate-mass A-type stars within 80 pc. Previous adaptive optics surveys of A-type stars are incomplete at separations &lt;20 au. Therefore, an LBI survey allows us to explore separations previously unexplored. Our sample consists of 54 A-type primaries with estimated masses between 1.44 and 2.93M⊙ and ages 10–790 Myr, which we observed with the Michigan Infra-Red Combiner-eXeter and Michigan Young Star Imager at Center for High Angular Resolution Astronomy instruments at the Center for High Angular Resolution Astronomy Array. We use the open source software CANDID to detect two new companions, seven in total, and we performed a Bayesian demographic analysis to characterize the companion population. We find the separation distribution consistent with being flat, and we estimate a power-law fit to the mass ratio distribution with index –0.13 ‑0.95+0.92  and a companion frequency of 0.25 ‑0.11+0.17  over mass ratios 0.1–1.0 and projected separations 0.01–27.54 au. We find a posterior probability of 0.53 and 0.04 that our results are consistent with extrapolations based on previous models of the solar-type and B-type companion population, respectively. Our results suggest that the close companion population to A-type stars is comparable to that of solar-type stars and that close companions to B-type stars are potentially more frequent, which may be indicative of increased disk fragmentation for stars ≳3M⊙.

Keywords: Multiple stars, Binary stars, A stars, Bayesian statistics, Stellar physics, Long baseline interferometry, Star formation
Impact of Radio-mode Feedback on the Covering Fraction of the Circumgalactic Medium of Quasars. Utilizing data from the Low-Frequency Array Two-meter Sky Survey and the Sloan Digital Sky Survey, we assemble a sample of 1469 projected quasar pairs with detected radio emissions from foreground quasars, as well as a control sample of 5846 pairs without detected radio emission, with the aim being to assess the impact of radio-mode feedback from quasars on the characteristics of the circumgalactic medium (CGM). By analyzing transverse Mg II absorption lines associated with foreground quasars in the spectra of background quasars, we observe that the Mg II covering fraction (fc) for quasars with detected radio emissions is significantly higher (∼3σ) than those without radio detections at projected distances dp ≤ 100 kpc, while no significant differences are noted on larger scales. Furtherly, if we remove the radio-quiet quasars from our sample, we find that this discrepancy between radio-loud quasars and the control group becomes even more significant. However, at larger projected distances, all types of quasars tend to have similar covering fractions. These findings suggest that radio-mode feedback from quasars may substantially influence the properties of the CGM on specific scales, particularly as quasars with radio emissions possess more powerful jets, enabling them to expel gas more effectively across various scales. This study offers new insights into the role of radio-mode feedback in galaxy evolution and underscores the importance of jets in regulating the gas distribution within the CGM.

Keywords: Broad-absorption line quasar
Mapping Ground-based Coronagraphic Images to Helioprojective-Cartesian Coordinate System by Image Registration. A few ground-based solar coronagraphs have been installed in western China for observing the low-layer corona in recent years. However, determining the helioprojective coordinates for the coronagraphic data with high precision is an important but challenging step for further research with other multiwavelength data. In this paper, we propose an automatic coronal image registration method that combines local statistical correlation and feature point matching to achieve accurate registration between ground-based coronal green-line images and space-based 211 Å images. Then, the accurate field of view information of the coronal green-line images can be derived, allowing the images to be mapped to the helioprojective Cartesian coordinates with an accuracy of no less than  0.″1 . This method has been extensively validated using 100 days of coronal data spanning an 11 yr period, demonstrating its broad applicability to ground-based coronagraphs equipped with green-line observations. It significantly enhances the scientific value of ground-based coronal data, enabling comprehensive studies of coronal transient activities and facilitating the joint analysis of data from multiple instruments. Additionally, it holds potential for future applications in improving the pointing accuracy of coronagraphs.

Keywords: Coronagraphic imaging, Solar corona, Astronomy data reduction
JWST Discovery of Warm Dust in the Circumgalactic Medium of the Makani Galaxy. We report the detection of near- and mid-infrared emission from polycyclic aromatic hydrocarbons (PAHs) out to ∼35 kpc in the Makani Galaxy, a compact massive galaxy with a record-breaking 100 kpc scale starburst-driven wind at redshift z = 0.459. The NIRCam and MIRI observations with JWST take advantage of a coincidental match between the PAH spectral features at 3.3, 7.7, and (11.3 + 12.2) μm in Makani and the bandpasses of the MIRI and NIRCam filters. The warm dust is not only detected in the cool-gas tracers of the galactic wind associated with the more recent (7 Myr) starburst episode, but also in the outer warm ionized gas wind produced by the older (0.4 Gyr) episode. The presence of PAHs in the outer wind indicates that the PAHs have survived the long (R/v ∼ 108 yr) journey to the halo despite the harsh environment of the galactic wind. The measured F1800W/F1130W flux ratios in the unresolved nucleus, inner halo (R = 10─20 kpc), and outer halo (R = 20─35 kpc), tracers of the PAH (11.3 + 12.2)/7.7 ratios, indicate decreasing starlight intensity incident on the PAHs, decreasing PAH sizes, and increasing PAH ionization fractions with increasing distance from the nucleus. These data provide the strongest evidence to date that the ejected dust of galactic winds survives the long journey to the circumgalactic medium, but is eroded along the way.

Keywords: Galactic winds, Starburst galaxies, Dust physics, Stellar feedback, Circumgalactic medium, Shocks
Intergalactic Wandering Stars in the Local Universe: Theoretical Predictions for Their Distance and Luminosity Distribution. Intergalactic wandering stars (IWSs) within 10 Mpc remain a poorly explored area of astronomy. Such stars, if they exist, are supposed to be wandering objects as they are not bound by the gravitational potential of any galaxy. We set out to conduct dedicated studies to unravel such a wandering stellar population. As the first paper of the series, in the present work, we model the distance distribution and luminosity function of IWSs formed via the Hills mechanism of the Galactic central massive black hole (GCMBH). We implement a numerical simulation to generate IWSs, taking the ejection history of the GCMBH and the stellar evolution process into consideration, and present their luminosity function in the distance range of 200 kpc–10 Mpc. Our results suggest that a few hundred thousand IWSs have been generated by the GCMBH via the Hills mechanism in the past 14 billion yr. These IWSs have an apparent magnitude peaking at 30–35 mag in the Sloan Digital Sky Survey r band, which are hard to detect. However, a few thousand of them at the bright end are detectable by upcoming wide-field deep surveys, such as the China Space Station Telescope and the Vera Rubin Observatory. The forthcoming discovery of such a wandering stellar population will open the door for a precise understanding of the matter constitution of the nearby intergalactic space and the dynamical history of galaxies in the local Universe.

Keywords: Local Group, Milky Way Galaxy physics, Hypervelocity stars, Milky Way Galaxy
The Impact of Silicate Grain Coagulation on Millimeter Emission from Massive Protostellar Disks. Hot accretion disks around massive protostars provide a unique opportunity to study ice-free silicate grains that cannot be investigated in protoplanetary disks. We conduct a self-consistent investigation into grain-size evolution and its impact on (sub)millimeter-wave emission from massive protostellar disks. Our radiative transfer modeling accounts for dust self-scattering and includes vertical temperature gradients in the disk structure. The results show that once silicate grains grow to sizes exceeding the observing wavelength, enhanced scattering dims the disk emission by 20%─30% relative to the blackbody emission expected at the disk surface temperature. By comparing our model with Atacama Large Millimeter/submillimeter Array 1.14 mm observations of the disk around the massive protostar GGD27-MM1, we constrain the threshold velocity for collisional fragmentation of silicate grains to approximately 15 m s−1. This fragmentation velocity is lower than the typical maximum collisional velocities in protoplanetary disks around low-mass stars, suggesting that collisional coagulation alone is insufficient for silicate dust to form rocky planetesimals in such environments. Furthermore, our analysis identifies two potential scenarios to better reproduce the bright inner-disk emission of GGD27-MM1. One possibility is that the grain growth is limited to 160 μm by another growth barrier (e.g., collisional bouncing), reducing scattering dimming. Alternatively, the stellar luminosity may be as much as five times higher than current estimates, compensating for the reduced brightness. Future multiwavelength observations, particularly at shorter submillimeter wavelengths, will be crucial to distinguish between these scenarios and further constrain silicate grain coagulation processes in massive protostellar disks.

Keywords: Massive stars, Astrophysical dust processes, Star formation, Protoplanetary disks, Planetesimals, Stellar accretion disks, Protostars
Diversity in Hydrogen-rich Envelope Mass of Type II Supernovae. III. The Mass-loss and Evolutionary Pathways of the Red Supergiant Progenitors. We present a comprehensive analysis of 32 type II supernovae (SNe II) with plateau phase photometry and late phase (nebular) spectroscopy available, aiming to bridge the gap between the surface and core of their red supergiant (RSG) progenitors. Using MESA+STELLA, we compute an extensive grid of SN II light-curve models originating from RSG with effective temperatures Teff around 3650 K and hydrogen-rich envelopes artificially stripped to varying degrees. These models are then used to derive the hydrogen-rich envelope masses MHenv for SNe II from their plateau phase light curves. Nebular spectroscopy further constrains the progenitor RSG's luminosity log Lprog and is employed to remove the degeneracies in light-curve modeling. The comparison between log Lprog–MHenv reveals that MHenv spans a broad range at the same log Lprog, and almost all SNe II have lower MHenv than the prediction of the default stellar wind models. We explore alternative wind prescriptions, binary evolution models, and the possibility of more compact RSG progenitors. Although binary interaction offers a compelling explanation for the nonmonotonicity and large scatter in the log Lprog–MHenv relation, the high occurrence rate of partially stripped RSGs cannot be accounted for by stable binary mass transfer alone without fine-tuned orbital parameters. This highlights that, despite being the most commonly observed class of core-collapse SNe, SNe II likely originate from a variety of mass-loss histories and evolutionary pathways that are more diverse and complex than typically assumed in standard stellar evolution models.

Keywords: Type II supernovae, Red supergiant stars
Effects of Outer Giant Planets on In Situ Formation of Inner Super-Earths. Recent studies have found an observational correlation between the presence of outer giant planets and inner super-Earths, which implies that outer giants do not suppress the formation of super-Earths. We simulate late-stage in situ planet formation in the presence of outer giant planets using N-body simulations. We investigate the effects of two sets of outer giants: the four solar system giant (SSG) planets and three dynamically active giant (DAG) planets. Compared to systems without outer giants, we find that systems with SSGs tend to form inner super-Earths that are more compact, coplanar, and circular, while the systems with DAGs form inner super-Earths that are more eccentric, inclined, and widely spaced, with lower intrinsic multiplicity. Including a contribution from systems that form with DAG planets allows us to match observable quantities of super-Earths, including their two-component eccentricity distribution. However, matching the observed population requires different formation conditions prior to the giant impact stage for systems with versus without giant planets. In our model, observed super-Earths that form in the presence of dynamically active outer giants emerge from disks with lower solid surface densities and without a depleted gas stage, suggesting that the giant planets may have reduced, but not prevented, delivery and/or accretion of solids in the inner disk. With a large enough sample of inner and outer systems, we could break down occurrence rates of inner super-Earths based on the properties of outer giants, and vice versa, and then compare these conditional probabilities with simulations.

Keywords: Planetary system evolution, Super Earths, Protoplanetary disks, N-body simulations, Planet formation, Dynamical evolution
An All-sky Survey of White Dwarf Merger Remnants: Far-Ultraviolet Is the Key. The majority of merging white dwarfs leave behind a white dwarf remnant. Hot/warm DQ white dwarfs with carbon-rich atmospheres have high masses and unusual kinematics. All evidence points to a merger origin. Here, we demonstrate that far-UV (FUV) and optical photometry provides an efficient way to identify these merger remnants. We take advantage of this photometric selection to identify 167 candidates in the Galaxy Evolution Explorer All-Sky Imaging Survey footprint, and provide follow-up spectroscopy. Out of the 140 with spectral classifications, we identify 75 warm DQ white dwarfs with Teff &gt; 10,000 K, nearly tripling the number of such objects known. Our sample includes 13 DAQ white dwarfs with spectra dominated by hydrogen and (weaker) carbon lines. Ten of these are new discoveries, including the hottest DAQ known to date, with Teff ≍ 23,000 K and M = 1.31M⊙. We provide a model atmosphere analysis of all warm DQ white dwarfs found, and present their temperature and mass distributions. The sample mean and standard deviation are Teff = 14,560 ± 1970 K and M = 1.11 ± 0.09M⊙. Warm DQs are roughly twice as massive as the classical DQs found at cooler temperatures. All warm DQs are found on or near the crystallization sequence. Even though their estimated cooling ages are of order 1 Gyr, their kinematics indicate an origin in the thick disk or halo. Hence, they are likely stuck on the crystallization sequence for ∼10 Gyr due to significant cooling delays from distillation of neutron-rich impurities. Future all-sky FUV surveys like Ultraviolet Explorer have the potential to significantly expand this sample.

Keywords: White dwarf stars, DQ stars, Stellar mergers
Absolute Calibration of Cluster Mira Variables to Provide a New Anchor for the Hubble Constant Determination. Mira variables in globular clusters can provide an accurate and precise absolute calibration of their period─luminosity relations (PLRs) to independently anchor the cosmic distance scale and determine the Hubble constant. We present homogeneous near-infrared (JHKs) time-series photometric observations of a sample of 55 candidate long-period variables in 18 globular clusters covering a wide metallicity range (−1.7 &lt; [Fe/H] &lt; − 0.1 dex). The Gaia proper motions, long-period variability information, and optical-infrared colors are used to identify 41 oxygen-rich Miras as members of the globular clusters. Mean luminosities of Miras in the JHKs bands are independently calibrated using the recommended distances and mean parallaxes to their host clusters. Cluster Mira PLRs exhibit scatter comparable to the Large Magellanic Cloud (LMC) variables and do not show any dependence on iron abundance for a wide range of metallicities. We establish the accuracy of cluster Miras as independent anchors by determining a distance modulus to the LMC, 18.45 ± 0.04 mag, in agreement with the 1.2% precise geometric distance. Our H-band photometry is transformed to derive Hubble Space Telescope F160W PLR for cluster Miras, providing a three-anchor baseline with the LMC and NGC 4258. We employ a three-anchor solution to determine distances to two type Ia supernovae host galaxies, NGC 1559 (31.39 ± 0.05 mag) and M101 (29.07 ± 0.04 mag), and provide a 3.7% measurement of the Hubble constant, H0 = 73.06 ± 2.67 km s−1 Mpc−1. Similar to Cepheids, our independent baseline solution results in a local H0 determination that is systematically larger than its inference from the early universe probes, further supporting the ongoing Hubble tension.

Keywords: Globular star clusters, Cosmology, Distance indicators, Hubble constant, Mira variable stars
Intermittency in Voyager's Magnetic Field Beyond the Heliosphere. As the two Voyager spacecraft traveled beyond the heliosphere, they encountered a magnetic field environment that had never been observed before. Studies have attempted to characterize this new regime by examining the magnetic field intermittency. This is typically done by fitting the optimal kappa distribution function and interpreting its q-statistics to characterize the magnetic field increments. Using this approach, recent findings concluded that beyond a certain distance, the magnetic field increments in the very local interstellar medium (VLISM) follow Gaussian statistics, unlike those both inside the heliosphere and in the region just beyond the widely accepted heliopause location, raising questions about the heliopause identification. This study explores this issue in detail by (1) optimizing the derivation of the distribution function, (2) examining whether and how the results depend on increment windows and time periods, and (3) determining the statistical behavior of the examined time series. Using magnetic field measurements from Voyager 1, we present two independent techniques and introduce a statistical framework to systematically analyze the distributions of magnetic field increments. Contrary to previous findings, we find that magnetic field increments in the VLISM do not follow a Gaussian distribution (κ → ∞) and instead are in the non-Gaussian range of kappa values (3–7, when analyzed on a 30 days statistical period). We further demonstrate how erroneous, statistically induced results can arise that mimic Gaussian-like results when mixing different structures in such analyses. Our results show that Voyager 1 still travels in the intermittent magnetic field environment of the VLISM.

Keywords: Space plasmas, Heliosphere, Interstellar magnetic fields, Interstellar medium, Heliosheath
Spectral Energy Distribution Fitting of Globular Clusters in NGC 4874: Masses and Metallicities. In most nearby galaxies, photometry of the integrated light of their globular clusters (GCs) has been obtained in only two filters, yielding just a single color index. However, NGC 4874, the brightest central galaxy in the Coma Cluster, now has Hubble Space Telescope photometry available in 10 filters, giving us a special opportunity to test spectral energy distribution (SED) fitting procedures on GCs in distant galaxies. We fitted 29 of the brightest GCs with a library of SEDs from E-MILES and calculated the best-fit metallicity and mass of each cluster. Using the fitted masses and luminosities derived from the reddest magnitudes, in the flat portion of the GC spectrum, we also calculated inferred mass-to-light ratios for our sample GCs; these were in the range (M/L) ≃ 2─4, slightly larger than the average values for Milky Way GCs but within the conventional range.

Keywords: Globular star clusters, Stellar colors, Metallicity
Reexamination of the CO Absorption Line in the M87 Nucleus. We analyzed the archival Atacama Large Millimeter/submillimeter Array data of the nuclear region of M87 and evaluated the molecular gas content from the CO(2–1) absorption line. We found an enigmatic variability in the absorption line depth between two epochs separated by only two months. We reexamined the data set used in the analysis and found that the bandpass calibration source within the same data set also revealed a similar absorption line structure. Furthermore, we observed a rise in the system noise temperature spectrum. We concluded that the absorption line structure identified in a previous study, and attributed to CO(2–1), does not originate from M87 but instead results from telluric contamination, and that we still have only the upper limit on the molecular gas around the nucleus of M87.

Keywords: Brightest cluster galaxies, Active galactic nuclei, Elliptical galaxies, Interstellar medium
JWST NIRCam Observations of the Globular Cluster Population of RXJ 2129.7+0005. We present an analysis of the globular cluster (GC) population in the galaxy cluster RXJ 2129.7+0005 (z = 0.234) based on JWST NIRCam imaging in three filters: F115W, F150W, and F200W. We use this material to provide a detailed look at the color–magnitude distribution of the GCs and their spatial distribution around the central giant galaxy. We identified 3160 GC candidates brighter than F150W = 29.5, and assessed photometric completeness through artificial star tests. We determined that the GCs follow a radial power-law distribution with an index of 1.58 ± 0.04, with the redder GCs exhibiting a slightly greater central concentration. Their spatial distribution is also highly elliptical, closely following the shape of the brightest cluster galaxy halo light.

Keywords: Galaxy clusters, AB photometry, Globular star clusters
The First Model-independent Chromatic Microlensing Search: No Evidence in the Gravitational Wave Catalog of LIGO–Virgo–KAGRA. The lensing of gravitational waves (GWs) due to intervening matter distribution in the Universe can lead to chromatic and achromatic signatures in the wave-optics and geometrical-optics limit, respectively. This makes it difficult to model the unknown mass distribution of the lens and hence requires a model-independent lensing detection technique from GW data. We perform the first model-independent microlensing search in the wave-optics limit on the 72 superthreshold GW events observed with both the LIGO detectors up to the third observation catalog, GWTC-3 of LIGO–Virgo–KAGRA, using the analysis method μ-GLANCE. These unmodelled searches pick up one plausible candidate, GW190408_181802, with a slightly above-threshold residual amplitude compared to the residual expected from detector noise. However, exploring the microlensing modulation signatures on this event, we do not find any conclusive evidence of the microlensing signal in the data. With this, we confidently rule out the presence of any statistically significant microlensing signal in the 72 events up to GWTC-3 in a model-independent way.

Keywords: Gravitational microlensing, Gravitational lensing, Gravitational waves