Sazuna/UAT_keywords huggingface dataset:
The Crucial Role of Third Body in Formation and Evolution of Contact Binary Systems: Evidence from CY Ari and IK Lyn. CY Ari and IK Lyn are two eclipsing binary systems that share the same spectral type but exhibit significantly different metallicities. Based on the Wilson–Devinney (W-D) method, the first photometric solutions are obtained by analyzing the new complete BVRcIc light curves. The completely eclipsing nature of the light curves allows for the determination of reliable photometric parameters for both systems. Analysis of the light curves indicates that the two systems are structurally similar. Both belong to W-type shallow contact binary systems, with nearly identical degrees of contact. The O ‑ C analysis demonstrates that the orbital periods of CY Ari and IK Lyn are increasing over the long term, with the increase rate for IK Lyn being significantly higher than that for CY Ari. This discrepancy may arise from different mass transfer rates from the secondary star to the primary star. Additionally, a periodic oscillation with a period of 5.4 yr has been detected in CY Ari, potentially attributable to the light-time effect of an unseen third body. An analysis of the age and evolutionary stage elucidates the reasons behind the divergent evolutionary paths of CY Ari and IK Lyn. The presence of the third body accelerates the evolution of CY Ari by removing angular momentum from the central binary pair. Although CY Ari was formed later than IK Lyn, it has evolved into a similar stage. This study provides critical evidence of the significant role played by a third body in the formation and evolution of contact binary systems.

Keywords: Close binary stars, Eclipsing binary stars, Contact binary stars, Stellar evolution
A Galaxy with an Extremely Blue Ultraviolet Slope β = ‑3 at z = 9.25 Identified by JWST Spectroscopy: Evidence for a Weak Nebular Continuum and Efficient Ionizing Photon Escape?. We investigate UV continuum slopes β of 863 galaxies at 4 &lt; z &lt; 14 using archival JWST/NIRSpec PRISM spectra obtained from major JWST Guaranteed Time Observations (GTO), Early Release Science (ERS), and General Observers (GO) programs, including JADES, CEERS, and UNCOVER. Among these galaxies, we identify a remarkable galaxy at z = 9.25, dubbed extremely blue galaxy 1 (EBG-1), with a significantly blue UV slope β = ‑2.99 ± 0.15, unlike the rest of the galaxies that exhibit red continua or ambiguous blue continua hindered by large uncertainties. We confirm that the β value negligibly changes by the data reduction and fitting wavelength ranges for UV emission/absorption line masking. The extreme blue slope, β = ‑3.0, rules out significant contributions from dust extinction or AGN activity. Comparing with stellar and nebular emission models, we find that such a blue UV slope cannot be reproduced solely by stellar models even with very young, metal-poor, or top-heavy contiguous star formation associated with strong nebular continua making the UV slopes red, but with a high ionizing photon escape fraction,  fescion≳0.5 , for a weak nebular continuum. While the Hβ emission line is not detected, likely due to the limited sensitivity of the spectrum, we find moderately weak [O III]λλ4959,5007 emission lines for the given star formation rate (3 M⊙ yr‑1) and stellar mass (108.0 M⊙) that are about 3 times weaker than the average emission lines, again suggestive of the high ionizing photon escape fraction,  fescion∼0.7  or more. EBG-1 would provide crucial insights into stellar and nebular continuum emission in high-redshift galaxies, serving as an example of the ionizing photon escaping site at the epoch of reionization.

Keywords: Galaxy formation, Ultraviolet color, Galaxy evolution, Reionization, High-redshift galaxies
Rapid Change in the Orbital Period of the Remnant of Nova Scorpii AD 1437 (IGR J17014-4306). IGR J17014-4306 is the longest orbital period (12.8 hr) deep-eclipsing intermediate polar known, where a massive white dwarf (WD) accretes matter from its companion star via an accretion disk. Based on photometric observations from the Transiting Exoplanet Survey Satellite space telescope and the American Association of Variable Star Observers database, 70 eclipse timings were determined. It was also confirmed that the spin pulse profile of the WD does change, which is due to the amplitude variation with opposite trends in spin frequency and its first harmonic. This may be related to fluctuations in the accretion rate. The spin period shows slight fluctuations but no significant changing trends. We constructed the O–C diagram and discovered that the orbital period is increasing at a high rate of  Ṗorb=+4.3(3)×10‑7days·yr‑1=+0.037(3)s·yr‑1 , which is comparable to those detected in compact binary supersoft X-ray sources and recurrent novae. This continuous increase in the orbital period is caused by the mass transfer from the less-massive companion to the WD on its thermal timescale at a high rate. All these findings suggest that IGR J17014-4306 is an interesting target to investigate nova eruption, the real angular momentum loss mechanism, and the overall evolution of cataclysmic variables.

Keywords: Close binary stars, Cataclysmic variable stars, Eclipsing binary stars, Orbital evolution
Magnetic Fields in the Pillars of Creation. Due to dust grain alignment with magnetic fields, dust polarization observations of far-infrared emission from cold molecular clouds are often used to trace magnetic fields, allowing a probe of the effects of magnetic fields on the star formation process. We present inferred magnetic field maps of the Pillars of Creation region within the larger M16 emission nebula, derived from dust polarization data in the 89 and 154 μm continuum using the Stratospheric Observatory For Infrared Astronomy/High-resolution Airborne Wideband Camera. We derive magnetic field strength estimates using the Davis─Chandrasekhar─Fermi method. We compare the polarization and magnetic field strengths to column densities and dust continuum intensities across the region to build a coherent picture of the relationship between star-forming activity and magnetic fields in the region. The projected magnetic field strengths derived are in the range of ∼50─130 μG, which is typical for clouds of similar n(H2), i.e., molecular hydrogen volume density on the order of 104─105 cm−3. We conclude that star formation occurs in the finger tips when the magnetic fields are too weak to prevent radial collapse due to gravity but strong enough to oppose OB stellar radiation pressure, while in the base of the fingers the magnetic fields hinder mass accretion and consequently star formation. We also support an initial weak-field model (&lt;50 μG) with subsequent strengthening through realignment and compression, resulting in a dynamically important magnetic field.

Keywords: Star forming regions, Molecular clouds, Far infrared astronomy, Star formation, Dust continuum emission, Polarimetry
AMUSE-Antlia. II. Intracluster X-Ray Population in the Antlia Cluster. We conduct a systematic survey of X-ray sources in the inner (r ∼ 200 kpc) region of the Antlia cluster based on Chandra observations, down to a source detection limit of L(0.5–8 keV) ∼ 4.2 × 10‑7 ph cm‑2 s‑1 (2 × 1038 erg s‑1). We present an X-ray source catalog with 202 sources and provide their coordinates, multiband flux information, and hardness ratios. We find a statistically significant excess at a significance level of 4.2σ with 37.6 excess sources beyond 3 times the mean effective radius of the two brightest central galaxies (BCGs). This implies that these excess sources could be a genuine intracluster X-ray population that is not associated with the bulk stellar component. Also, the increased number of excess sources in the fields containing a BCG implies a potential connection between the excess sources and BCGs. The discovery of these sources in the Antlia cluster, together with previous research of similar findings in the other two nearby clusters, Virgo and Fornax, indicates that the intracluster X-ray population could be universal in nearby galaxy clusters. Furthermore, we discuss the candidate origins of the excess sources, including low-mass X-ray binaries (LMXBs) associated with intracluster light (ICL-LMXBs), LMXBs in globular clusters (GC-LMXBs), and supernova-kicked LMXBs (SN-kicked LMXBs). We estimate that the contribution of ICL-LMXBs, which should include the LMXBs related to the stellar halo surrounding BCGs, is unlikely to dominate the intracluster X-ray population in Antlia. Meanwhile, GC-LMXBs and SN-kicked LMXBs, each component could contribute ∼30% to the total excess sources.

Keywords: Galaxy clusters, X-ray binary stars
The Impact of Applying Black Hole–Host Galaxy Scaling Relations to Large Galaxy Populations. Supermassive black holes (SMBHs) with dynamically measured masses have shown empirical correlations with host galaxy properties. These correlations are often the only method available to estimate SMBH masses and gather statistics for large galaxy populations across a range of redshifts, even though the scaling relations themselves are derived from a small subset of nearby galaxies. Depending on the scaling relation used, estimated SMBH masses can vary significantly. The most widely used scaling relations are the MBH–Mbulge and MBH–σ relations, where Mbulge is galaxy bulge mass and σ is the bulge velocity dispersion. In this paper, we determine how severely the choice of scaling relation impacts SMBH mass estimates for different subsets of a large galaxy population. For this analysis, we use a sample of ∼400,000 galaxies, including 1240 Type 1 active galactic nuclei from the Sloan Digital Sky Survey. We calculate SMBH masses from MBH–Mbulge and MBH–σ and compare to single-epoch virial SMBH masses from broad-line Hβ, which are derived independently of black hole–host galaxy scaling relations. We find that SMBH masses derived from the single-epoch virial relation for Hβ are better reproduced by MBH–σ than MBH–Mbulge. Finally, in cases where σ and Mbulge cannot be measured directly, we show that it is possible to infer σ from photometry with more accuracy than we can infer Mbulge.

Keywords: Supermassive black holes, Active galaxies, Galaxies
Integrated Galaxy Light from Stacking 10<SUP>5</SUP> Random Pointings in the Dark Energy Survey Data. We present a new technique for measuring the integrated galaxy light (IGL) with stacked image data from the Dark Energy Survey (DES). We extract 1' × 1' cutouts from nearly 100,000 randomly selected positions in the g, r, i, z, and Y bands from the DES Data Release 2 maps. We generate source catalogs and masks for each cutout, and the images are subsequently stacked to generate deep images of the sky both with and without sources. The IGL is then calculated by taking the difference in average brightness between stacks that contain galaxies and stacks in which galaxies have been masked. We find IGL values of g = 4.27 ± 0.28, r = 6.97 ± 0.42, i = 8.66 ± 0.53, z = 10.16 ± 0.7, and Y = 13.78 ± 2.35 nW m‑2 sr‑1. These measurements, which require no foreground estimation or removal, are in agreement with previously reported IGL values derived from galaxy number counts and other methods. This stacking technique reduces the sensitivity to diffuse local backgrounds but is not sensitive to large-scale diffuse extragalactic background light.

Keywords: Optical astronomy, Cosmic background radiation
Multifrequency Radio Observations of the Magnetar Swift J1818.0–1607. We report on Green Bank Telescope observations of the radio magnetar Swift J1818.0–1607 between 820 MHz and 35 GHz, taken from 6 to 9 months after its 2020 March outburst. We obtained multihour observations at six frequencies, recording polarimetric, spectral, and single-pulse information. The spectrum peaks at a frequency of 5.4 ± 0.6 GHz, making Swift J1818.0–1607 one of many radio magnetars that exhibit a gigahertz-peaked spectrum. The radio flux decays steeply above the peak frequency, with in-band spectral indices α &lt; ‑2.3 above 9 GHz. The emission is highly (&gt;50%) linearly polarized, with a lower degree (&lt;30%) of circular polarization that can change handedness between single pulses. Across the frequency range of our observations, the time-integrated radio profiles share a common shape: a narrow "pulsar-like" central component flanked by "magnetar-like" components comprised of bright, spiky subpulses. The outer profile components exhibit larger degrees of flux modulation when compared to the central pulse component.

Keywords: Magnetars, Radio pulsars
A Possible Common Physics Picture Reflected by the Gamma-Ray Emission of the Galactic Center. Long-term observations of the Galactic center by Fermi and HESS have revealed a novel phenomenon: the high-energy gamma-ray spectrum from the gamma-ray source HESS J1745-290 exhibits a double power-law structure. In this study, we propose a new explanation for this phenomenon. We suggest that the low-energy (GeV) power-law spectrum originates from interactions between trapped background "sea" cosmic ray particles and the dense gaseous environment near the Galactic center. In contrast, the bubble-like structure in the high-energy (TeV) spectrum is produced by protons accelerated during active phases of the Galactic center, through the same physical process. Based on this framework, we first calculate the gamma-ray emission generated by cosmic ray protons accelerated in the Galactic center. Then, using a spatially dependent cosmic ray propagation model, we compute the energy spectrum of background "sea" cosmic ray protons and their associated diffuse gamma-ray emission in the Galactic center region. The results closely reproduce the observations from Fermi-LAT and HESS, suggesting that their long-term data support this picture: high-energy cosmic rays in the local region originate from nearby cosmic ray sources, while low-energy cosmic rays are a unified contribution from distant cosmic ray sources. We anticipate that this double power-law structure may be widely present in the halo of a Galactic cosmic-ray source or a slow-diffusion region. We hope that future observations will detect more such sources, allowing us to further test and validate our model.

Keywords: Galactic cosmic rays, Diffuse radiation, Galactic center
Leaky Dust Traps in Planet-embedded Protoplanetary Disks. From the survival of dust disks for a few Myr to the establishment of chemical dichotomy, dust traps are expected to play a pivotal role in sculpting protoplanetary disks and the early planet formation process. These traps may not be perfect, as evidenced by both numerical simulations and the observations of disks with gaps and cavities, inside which we detect some amounts of both gas and dust. Using two-fluid hydrodynamic global simulations in both 2D and 3D, we directly compute the dynamics of dust grains as they aerodynamically interact with the disk gas that is being perturbed by an embedded planet. In both 2D and 3D, we find the dust trap to be more leaky for a lower-mass planet and for a more turbulent disk. More crucially, we find that the fraction of dust mass that remains trapped within the pressure bump can be up to an order of magnitude more reduced in 3D compared to 2D, with all else being equal. Our simulations show a complex behavior of dust radial motion that is both azimuthally and poloidally nonuniform, with the overall dynamics dominated by the dust coupling to the gas flow even for Stokes number 0.1. The leaky traps we find suggest that the pebble isolation mass is likely not truly isolating and that gap-opening planets do not establish an unconditional impermeable barrier. Our findings have implications for recent JWST MINDS results, which show that volatiles, including water, are present in the inner regions of disks hosting outer dust rings.

Keywords: Astrophysical dust processes, Planetary-disk interactions, Protoplanetary disks
An ALMA Study of Molecular Complexity in the Hot Core G336.99-00.03 MM1. High-mass star formation involves complex processes, with the hot core phase playing a crucial role in chemical enrichment and the formation of complex organic molecules. However, molecular inventories in hot cores remain limited. Using data from the Atacama Large Millimeter/submillimeter Array Three-millimeter Observations of Massive Star-forming regions survey, the molecular composition and evolutionary stages of two distinct millimeter continuum sources in the high-mass star-forming region G336.99-00.03 have been characterized. MM1, with 19 distinct molecular species detected, along with eight isotopologues and several vibrationally/torsionally excited states, has been identified as a hot core. MM2, with only five species identified, was defined as a H II region. Isotopic ratios in MM1 were derived, with 12C/13C ranging from 16.0 to 29.2, 16O/18O at 47.7, and 32S/34S at 19.2. Molecular abundances in MM1 show strong agreement with other sources and three-phase warm-up chemical models within an order of magnitude for most species. Formation pathways of key molecules were explored, revealing chemical links and reaction networks. This study provides a detailed molecular inventory of two millimeter continuum sources, shedding light on the chemical diversity and evolutionary processes in high-mass star-forming regions. The derived molecular parameters and isotopic ratios offer benchmarks for astrochemical models, paving the way for further investigation into the formation and evolution of complex organic molecules during the hot core phase.

Keywords: Isotopic abundances, Interstellar medium, Star formation, Complex organic molecules
C-19 and Hot, Wide Star Streams. The C-19 star stream has the abundance characteristics of an unusually metal-poor globular cluster but kinematically is uncharacteristically hot and wide for a cluster stream, having a line-of-sight velocity dispersion of 7 ± 2 km s‑1 and a 1σ width of 240 pc. We show that the tidal dissolution of an old, lower-mass globular cluster in a cold dark matter (CDM) galactic halo can create a hot, wide stream currently near orbital apocenter. A cosmological Milky Way n-body simulation motivates the parameters for an evolving Milky Way halo potential containing an orbiting subhalo population in which we model a star cluster progenitor of C-19. The same model parameters have been used for a GD-1 stream model. The ∼7 km s‑1 velocity dispersion is readily accomplished with an evolving CDM subhalo population, a progenitor cluster mass ≃2 × 104 M⊙, and an orbit that keeps the progenitor orbital pericenter within about 10 kpc of the Milky Way dark halo or its precursors.

Keywords: Galaxy dark matter halos, Cold dark matter, Milky Way dark matter halo, Dark matter
JAGB 2.0: Improved Constraints on the J-region Asymptotic Giant Branch─based Hubble Constant from an Expanded Sample of JWST Observations. The J-region asymptotic giant branch (JAGB) is an overdensity of stars in the near-infrared, attributed to carbon-rich AGB stars, and recently used as a standard candle for measuring extragalactic distances and the Hubble constant. Using JWST in Cycle 2, we extend JAGB measurements to six hosts of nine Type Ia supernovae (SNe Ia; NGC 2525, NGC 3147, NGC 3370, NGC 3447, NGC 5468, and NGC 5861), with two at D ∼ 40 Mpc, all calibrated by the maser host NGC 4258. We investigate the effects of incompleteness and are unable to recover a JAGB measurement for NGC 3147. We compile all JWST JAGB observations of SN Ia hosts, 15 galaxies hosting 18 SNe Ia, from the SH0ES and CCHP programs, and employ all literature measures. We find no significant mean difference between these distances and those from Hubble Space Telescope Cepheids, −0.03 ± 0.02 (stat.) ± 0.05 (sys.) mag. We find a difference of 0.11 ± 0.022 mag between JAGB mode measurements in the CCHP analyses of two fields in NGC 4258, a feature also seen in two SH0ES fields (see field-to-field variations in S. Li et al.), indicating significant variation of NGC 4258 JAGB measurements, which produce a large absolute calibration uncertainty. Variations are also seen in the shape of the JAGB luminosity function (LF) across galaxies so that different measures produce different values of the Hubble constant. We look for but do not (yet) find a standardizing relation between JAGB LF skew or color dependence and the apparent variation. Using the middle result of all JAGB measures to calibrate SNe Ia yields a Hubble constant of H0 = 73.3 ± 1.4 (stat.) ± 2.0 (sys.) km s−1 Mpc−1 with the systematic dominated by apparent differences across the NGC 4258 calibrating fields or their measures.

Keywords: Luminosity function, Observational cosmology, Standard candles, Carbon stars, Distance indicators, Hubble constant, Asymptotic giant branch stars, James Webb Space Telescope, Stellar distance, Galaxies
Magnetogram-matching Biot–Savart Law and Decomposition of Vector Magnetograms. We generalize a magnetogram-matching Biot–Savart law (BSL) from planar to spherical geometry. For a given coronal current density J, this law determines the magnetic field  B∼  whose radial component vanishes at the surface. The superposition of  B∼  with a potential field defined by a given surface radial field, Br, provides the entire configuration where Br remains unchanged by the currents. Using this approach, we (1) upgrade our regularized BSLs for constructing coronal magnetic flux ropes (MFRs) and (2) propose a new method for decomposing a measured photospheric magnetic field as  B=Bpot+BT+BS∼ , where the potential, Bpot, toroidal, BT, and poloidal,  BS∼ , fields are determined by Br, Jr, and the surface divergence of B–Bpot, respectively, all derived from magnetic data. Our BT is identical to the one in the alternative Gaussian decomposition by P. W. Schuck et al., while Bpot and  BS∼  are different from their poloidal fields  BP&lt;  and  BP&gt; , which are potential in the infinitesimal proximity to the upper and lower side of the surface, respectively. In contrast, our  BS∼  has no such constraints and, as Bpot and BT, refers to the same upper side of the surface. In spite of these differences, for a continuous J distribution across the surface, Bpot and  BS∼  are linear combinations of  BP&lt;  and  BP&gt; . We demonstrate that, similar to the Gaussian method, our decomposition allows one to identify the footprints and projected surface-location of MFRs in the solar corona, as well as the direction and connectivity of their currents.

Keywords: Solar activity, Solar prominences, Solar magnetic fields, Solar filaments
Discovery of a Giant Molecular Cloud at the Midpoint of the Galactic Bar Dust Lanes: M4.7─0.8. We present the detection of a previously unknown giant molecular cloud (GMC) located at the midpoint of the Galactic Bar Dust Lanes (M4.7─0.8), using spectral line observations taken with the Green Bank Telescope. This ∼60 pc long GMC is associated with accreting material that is transitioning from the quieter Galactic disk environment to the more extreme central molecular zone (CMZ) environment. Our 24 GHz single-dish radio observations targeted the NH3 (1,1)−(4,4) and HC5N (9−8), known dense gas tracers. The observations reveal the main features of the GMC, which we have dubbed the "Nexus" and "Filament," covering a 0 .° 5 × 0 .° 25 area at 31″ angular resolution. In this publication, we investigate the gas kinematics within the observed region and compare the distribution of molecular emission to previous infrared surveys to better understand the dust component. The observed gas tracers show centrally condensed cores corresponding to the positions of high dust column densities and low dust temperatures. We report the detection of a previously unknown NH3 (3,3) maser, along with a 70 μm source association, which supports the identification of this region as being actively star-forming. Gas emission in this region shows broad linewidths, comparable to values seen in CMZ clouds. The overall description of this cloud that we present is that of a highly dynamic region comprising dense gas and dust. This encapsulates a wide range of features associated with star formation, in addition to material transport related to the CMZ.

Keywords: Giant molecular clouds, Galaxy bars, Interstellar medium