Sazuna/UAT_keywords huggingface dataset:
Constraining Annihilating Dark Matter Mass by the Radio Continuum Spectral Data of a High-redshift Galaxy Cluster. In the past decade, the properties of annihilating dark matter models were examined by various kinds of data, including the data of gamma-rays, radio waves, X-rays, positrons, electrons, antiprotons and neutrinos. In particular, most of the studies focus on the data of our Galaxy, nearby galaxies (e.g., M31 galaxy) or nearby galaxy clusters (e.g., Fornax cluster). In this article, we examine the archival radio continuum spectral data of a relatively high-redshift galaxy cluster (A697 cluster) to constrain the properties of annihilating dark matter. We find that leptophilic annihilation channels (e+ e-, μ+ μ-, and τ+ τ-) can give very good fits to the radio continuum spectrum of the A697 cluster.

Keywords: Dark matter, Particle astrophysics
Discovery of a Radio Relic in the Massive Merging Cluster SPT-CL J2023-5535 from the ASKAP-EMU Pilot Survey. The ASKAP-EMU survey is a deep wide-field radio continuum survey designed to cover the entire southern sky and a significant fraction of the northern sky up to +30°. Here, we report a discovery of a radio relic in the merging cluster SPT-CL J2023-5535 at z = 0.23 from the ASKAP-EMU pilot 300 square degree survey (800-1088 MHz). The deep high-resolution data reveal a ∼2 Mpc scale radio halo elongated in the east-west direction, coincident with the intracluster gas. The radio relic is located at the western edge of this radio halo stretched ∼0.5 Mpc in the north-south orientation. The integrated spectral index of the radio relic within the narrow bandwidth is ${\alpha }_{800\,\mathrm{MHz}}^{1088\,\mathrm{MHz}}=-0.76\pm 0.06$ . Our weak-lensing analysis shows that the system is massive ( ${M}_{200}=1.04\pm 0.36\times {10}^{15}\,{M}_{\odot }$ ) and composed of at least three subclusters. We suggest a scenario, wherein the radio features arise from the collision between the eastern and middle subclusters. Our discovery illustrates the effectiveness of the ASKAP-EMU survey in detecting diffuse emissions in galaxy clusters and when completed, the survey will greatly increase the number of merging cluster detections with diffuse radio emissions.

Keywords: Galaxy clusters, X-ray astronomy, Weak gravitational lensing, Radio telescopes, Radio continuum emission
Magnetic Flux of Active Regions Determining the Eruptive Character of Large Solar Flares. We establish the largest eruptive/confined flare database to date and analyze 322 flares of Geostationary Operational Environmental Satellite class M1.0 and larger that occurred during 2010-2019, i.e., almost spanning all of solar cycle 24. We find that the total unsigned magnetic flux ( ${{\rm{\Phi }}}_{\mathrm{AR}}$ ) of active regions (ARs) is a key parameter governing the eruptive character of large flares, with the proportion of eruptive flares exhibiting a strong anticorrelation with ${{\rm{\Phi }}}_{\mathrm{AR}}$ . This means that an AR containing a large magnetic flux has a lower probability that the large flares it produces will be associated with a coronal mass ejection (CME). This finding is supported by the high positive correlation we obtained between the critical decay index height and ${{\rm{\Phi }}}_{\mathrm{AR}}$ , implying that ARs with a larger ${{\rm{\Phi }}}_{\mathrm{AR}}$ have a stronger magnetic confinement. Moreover, the confined flares originating from ARs larger than $1.0\times {10}^{23}$ Mx have several characteristics in common: stable filament, slipping magnetic reconnection, and strongly sheared post-flare loops. Our findings reveal new relations between the magnetic flux of ARs and the occurrence of CMEs in association with large flares. The relations obtained here provide quantitative criteria for forecasting CMEs and adverse space weather, and have important implications for "superflares" on solar-type stars and stellar CMEs.

Keywords: Solar flares, Stellar coronal mass ejections, Stellar flares, Solar coronal mass ejections, Solar magnetic fields, Solar activity
The Alignment of Satellite Systems with Cosmic Filaments in the SDSS DR12. Galaxies, as well as their satellites, are known to form within the cosmic web, the large, multi-scale distribution of matter in the universe. It is known that the surrounding large-scale structure (LSS) can impact and influence the formation of galaxies, e.g., the spin and shape of halos or galaxies are correlated with the LSS and the correlation depends on halo mass or galaxy morphology. In this work, we use group and filament catalogs constructed from the SDSS DR12 to investigate the correlation between satellite systems and the large-scale filaments they are located in. We find that the distribution of satellites is significantly correlated with filaments, namely the major axis of the satellite systems are preferentially aligned with the spine of the closest filament. Stronger alignment signals are found for the cases where the system is far from the filament spine, while systems close to the filament spine show significantly weaker alignment. Our results suggest that satellites are accreted along filaments, which agrees with previous works. The case where the system is far from the filament spine may help us to understand how the filament forms as well as the peculiar satellite distribution in the local universe.

Keywords: Observational astronomy, Large-scale structure of the universe, Astrostatistics, Galaxy evolution, Galaxies
Spectral Diagnostics of Solar Photospheric Bright Points. Through the use of the high-resolution spectral data and the broadband imaging obtained with the Goode Solar Telescope at the Big Bear Solar Observatory on 2013 June 6, the spectra of three typical photospheric bright points (PBPs) have been analyzed. Based on the Hα and Ca II 8542 Å line profiles, as well as the TiO continuum emission, for the first time, the non-LTE semiempirical atmospheric models for the PBPs are computed. The attractive characteristic is the temperature enhancement in the lower photosphere. The temperature enhancement is about 200-500 K at the same column mass density as in the atmospheric model of the quiet-Sun. The total excess radiative energy of a typical PBP is estimated to be 1 × 1027-2 × 1027 erg, which can be regarded as the lower limit energy of the PBPs. The radiation flux in the visible continuum for the PBPs is about 5.5 × 1010 erg cm-2 s-1. Our result also indicates that the temperature in the atmosphere above PBPs is close to that of a plage. It gives clear evidence that PBPs may contribute significantly to the heating of the plage atmosphere. Using our semiempirical atmospheric models, we estimate self-consistently the average magnetic flux density B in the PBPs. It is shown that the maximum value is about 1 kG, and it decreases toward both higher and lower layers, reminding us of the structure of a flux tube between photospheric granules.

Keywords: Solar atmosphere, Solar chromosphere, Solar photosphere
Ionized and Atomic Interstellar Medium in the z = 6.003 Quasar SDSS J2310+1855. Observing the interstellar medium (ISM) in the z ≳ 6 quasar host galaxies is essential for understanding the coevolution between supermassive black holes and their hosts. To probe the gas physical conditions and search for imprints of active galactic nuclei (AGNs) on the ISM, we report ALMA observations of the [N II]122 μm and [O I]146 μm lines and the underlying continuum from the z = 6.003 quasar SDSS J231038.88+185519.7. Together with previous [C II]158 μm and [O III]88 μm observations, we use the ratios of these fine-structure lines to probe the ISM properties. Similar to other high-z systems, this object exhibits a [C II]158 μm/[O I]146 μm ratio comparable to the lowest values found in local (ultra)luminous infrared galaxies, suggesting a "warmer" and "denser" gas component compared to typical local systems. The [O III]88 μm/[O I]146 μm ratio is lower than that of other local and high-z systems, indicating a smaller ionized gas fraction in this quasar. The [O III]88 μm/[N II]122 μm ratio is comparable to that of local systems and suggests a metallicity of Z/Z⊙ = 1.5-2.1. Based on the [N II]122 μm detection, we estimate that 17% of the [C II]158 μm emission is associated with ionized gas. The [N II]122 μm line shows a "flux deficit" comparable to local systems. The [O I]146 μm line, with an [O I]146 μm/FIR ratio &gt;2× than expected from the local relation, indicates no [O I]146 μm deficit. The low [C II]158 μm/[O I]146 μm ratio, together with the high [O I]146 μm/FIR ratio in J2310+1855, reveals that the warm and dense gas is likely a result of AGN heating of the ISM.

Keywords: Early universe, Quasars, Active galactic nuclei, Dust continuum emission, Interstellar medium, Submillimeter astronomy, High-redshift galaxies
A SOFIA Survey of [C II] in the Galaxy M51. II. [C II] and CO Kinematics across the Spiral Arms. We present the first complete, velocity-resolved [C II] 158 μm image of the M51 grand-design spiral galaxy, observed with the upgraded German Receiver for Astronomy at Terahertz frequencies instrument on the Stratospheric Observatory for Infrared Astronomy. [C II] is an important tracer of various phases of the interstellar medium (ISM), including ionized gas, neutral atomic, and diffuse molecular regions. We combine the [C II] data with H I, CO, 24 μm dust continuum, FUV, and NIR K-band observations to study the evolution of the ISM across M51's spiral arms in both position-position and position-velocity space. Our data show strong velocity gradients in H I, 12CO, and [C II] at the locations of the stellar arms (traced by K-band data) with a clear offset in position-velocity space between upstream molecular gas (traced by 12CO) and downstream star formation (traced by [C II]). We compare the observed position-velocity maps across the spiral arms with synthetic observations from numerical simulations of galaxies with both dynamical and quasi-stationary steady spiral arms that predict both tangential and radial velocities at the location of the spiral arms. We find that our observations, based on the observed velocity gradients and associated offset between CO and [C II], are consistent with the presence of shocks in the spiral arms in the inner parts of M51 and in the arm connecting the companion galaxy, M51b, in the outer parts of M51.

Keywords: Galaxies, Interstellar medium, Galactic and extragalactic astronomy
Giant Planet Formation Models with a Self-consistent Treatment of the Heavy Elements. We present a new numerical framework to model the formation and evolution of giant planets. The code is based on the further development of the stellar evolution toolkit Modules for Experiments in Stellar Astrophysics. The model includes the dissolution of the accreted planetesimals/pebbles, which are assumed to be made of water ice, in the planetary gaseous envelope, and the effect of envelope enrichment on the planetary growth and internal structure is computed self-consistently. We apply our simulations to Jupiter and investigate the impact of different heavy-element and gas accretion rates on its formation history. We show that the assumed runaway gas accretion rate significantly affects the planetary radius and luminosity. It is confirmed that heavy-element enrichment leads to shorter formation timescales due to more efficient gas accretion. We find that with heavy-element enrichment Jupiter's formation timescale is compatible with typical disks' lifetimes even when assuming a low heavy-element accretion rate (oligarchic regime). Finally, we provide an approximation for the heavy-element profile in the innermost part of the planet, providing a link between the internal structure and the planetary growth history.

Keywords: Exoplanet formation, Extrasolar gaseous giant planets, Planet formation
VLA Limits on Intermediate-mass Black Holes in 19 Massive Globular Clusters. The NSF's Karl G. Jansky Very Large Array (VLA) was used at 3 cm to search for accretion signatures from intermediate-mass black holes (IMBHs) in 19 globular star clusters (GCs) in NGC 3115, an early-type galaxy at a distance of 9.4 Mpc. The 19 GCs have stellar masses M⋆ ∼ (1.1-2.7) × 106 M⊙, with a mean $\overline{{M}_{\star }}\sim 1.8\times {10}^{6}\,{M}_{\odot }$ . None were detected. An IMBH accretion model was applied to the individual GCs and their radio stack. The radio-stacked GCs have an IMBH mass $\overline{{M}_{\mathrm{IMBH}}}\lt 1.7\times {10}^{5}\,{M}_{\odot }$ and mass fraction $\overline{{M}_{\mathrm{IMBH}}}/\overline{{M}_{\star }}\lt 9.5 \% $ , with each limit being uncertain by a factor of about 2.5. The latter limit contrasts with the extremes of some stripped nuclei, suggesting that the set of stacked GCs in NGC 3115 is not a set of such nuclei. The radio luminosities of the individual GCs correspond to X-ray luminosities LX &lt; (3.3-10) × 1038 erg s-1, with a factor of about 2.5 uncertainty. These limits predicted for putative IMBHs in the GCs are consistent with extant Chandra observations. Finally, a simulated observation with a next-generation VLA demonstrates that accretion signatures from IMBHs in GCs can be detected in a radio-only search, yet they elude detection in an X-ray-only search due to confusion from X-ray binaries in the GCs.

Keywords: Globular star clusters, Intermediate-mass black holes, Accretion, Aperture synthesis, Early-type galaxies
SCExAO/CHARIS High-contrast Imaging of Spirals and Darkening Features in the HD 34700 A Protoplanetary Disk. We present Subaru/SCExAO+Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS) broadband (JHK-band) integral field spectroscopy of HD 34700 A. CHARIS data recover HD 34700 A's disk ring and confirm multiple spirals discovered by Monnier et al. We set limits on substellar companions of ∼12 MJup at 0"3 (in the ring gap) and ∼5 MJup at 0"75 (outside the ring). The data reveal darkening effects on the ring and spiral, although we do not identify the origin of each feature such as shadows or physical features related to the outer spirals. Geometric albedos converted from the surface brightness suggest a greater scale height and/or prominently abundant submicron dust at position angles between ∼45° and 90°. Spiral fitting resulted in very large pitch angles (∼30°-50°); a stellar flyby of HD 34700 B or infall from a possible envelope is perhaps a reasonable scenario to explain the large pitch angles.

Keywords: Coronagraphic imaging, Protoplanetary disks
On Measuring Divergence for Magnetic Field Modeling. A physical magnetic field has a divergence of zero. Numerical error in constructing a model field and computing the divergence, however, introduces a finite divergence into these calculations. A popular metric for measuring divergence is the average fractional flux $\left\langle | {f}_{i}| \right\rangle $ . We show that $\left\langle | {f}_{i}| \right\rangle $ scales with the size of the computational mesh, and may be a poor measure of divergence because it becomes arbitrarily small for increasing mesh resolution, without the divergence actually decreasing. We define a modified version of this metric that does not scale with mesh size. We apply the new metric to the results of DeRosa et al., who measured $\left\langle | {f}_{i}| \right\rangle $ for a series of nonlinear force-free field models of the coronal magnetic field based on solar boundary data binned at different spatial resolutions. We compute a number of divergence metrics for the DeRosa et al. data and analyze the effect of spatial resolution on these metrics using a nonparametric method. We find that some of the trends reported by DeRosa et al. are due to the intrinsic scaling of $\left\langle | {f}_{i}| \right\rangle $ . We also find that different metrics give different results for the same data set and therefore there is value in measuring divergence via several metrics.

Keywords: Computational methods, Magnetic fields, Solar corona
Analysis of Red Supergiants in VDBH 222. Recent surveys uncovered new young massive clusters (YMCs) that host dozens of red supergiants (RSGs) in the inner Milky Way. These clusters are ideal for studying the most recent and violent star formation events in the inner Galaxy. However, due to the high extinction that affects the Galactic plane, they need to be studied through infrared (IR) spectroscopy. IR spectra of RSGs have proven to be powerful tools for obtaining chemical abundances. We present the first [Fe/H] measurement (-0.07 ± 0.02) for the YMC VdBH 222 through analysis of its RSGs using Very Large Telescope/X-shooter spectra. We find no evidence for multiple stellar populations in this YMC, contrary to what is routinely observed in older massive clusters.

Keywords: Chemical abundances, Red supergiant stars, Star clusters
White Dwarfs in the Era of the LSST and Its Synergies with Space-based Missions. With the imminent start of the Legacy Survey for Space and Time (LSST) at the Vera C. Rubin Observatory and several new space telescopes expected to begin operations later in this decade, both time-domain and wide-field astronomy are on the threshold of a new era. In this paper, we use a new multicomponent model for the distribution of white dwarfs (WDs) in our Galaxy to simulate the WD populations in four upcoming wide-field surveys (i.e., LSST, Euclid, the Roman Space Telescope, and the Cosmological Advanced Survey Telescope for Optical and uv Research) and use the resulting samples to explore some representative WD science cases. Our results confirm that LSST will provide a wealth of information for Galactic WDs, detecting more than 150 million WDs at the final depth of its stacked 10 yr survey. Within this sample, nearly 300,000 objects will have 5σ parallax measurements, and nearly 7 million will have 5σ proper-motion measurements, allowing the detection of the turnoff in the halo WD luminosity function and the discovery of more than 200,000 ZZ Ceti stars. The wide wavelength coverage that will be possible by combining LSST data with observations from Euclid and/or the Roman Space Telescope will also discover WDs with debris disks, highlighting the advantages of combining data between the ground- and space-based missions.

Keywords: Surveys, White dwarf stars, Star counts
Carnegie Supernova Project II: The Slowest Rising Type Ia Supernova LSQ14fmg and Clues to the Origin of Super-Chandrasekhar/03fg-like Events. The Type Ia supernova (SN Ia) LSQ14fmg exhibits exaggerated properties that may help to reveal the origin of the "super-Chandrasekhar" (or 03fg-like) group. The optical spectrum is typical of a 03fg-like SN Ia, but the light curves are unlike those of any SNe Ia observed. The light curves of LSQ14fmg rise extremely slowly. At -23 rest-frame days relative to B-band maximum, LSQ14fmg is already brighter than ${M}_{V}=-19$ mag before host extinction correction. The observed color curves show a flat evolution from the earliest observation to approximately 1 week after maximum. The near-infrared light curves peak brighter than -20.5 mag in the J and H bands, far more luminous than any 03fg-like SNe Ia with near-infrared observations. At 1 month past maximum, the optical light curves decline rapidly. The early, slow rise and flat color evolution are interpreted to result from an additional excess flux from a power source other than the radioactive decay of the synthesized 56Ni. The excess flux matches the interaction with a typical superwind of an asymptotic giant branch (AGB) star in density structure, mass-loss rate, and duration. The rapid decline starting at around 1 month past B-band maximum may be an indication of rapid cooling by active carbon monoxide (CO) formation, which requires a low-temperature and high-density environment. These peculiarities point to an AGB progenitor near the end of its evolution and the core degenerate scenario as the likely explosion mechanism for LSQ14fmg. * This paper includes data gathered with the 1 m Swope and 2.5 m du Pont telescopes at Las Campanas Observatory, Chile, and the Nordic Optical Telescope at the Observatorio del Roque de los Muchachos, La Palma, Spain.

Keywords: Asymptotic giant branch stars, Type Ia supernovae, Stellar winds
On the Fraction of X-Ray-weak Quasars from the Sloan Digital Sky Survey. We investigate systematically the X-ray emission from type 1 quasars using a sample of 1825 Sloan Digital Sky Survey non-broad absorption line (non-BAL) quasars with Chandra archival observations. A significant correlation is found between the X-ray-to-optical power-law slope parameter (αOX) and the 2500 Å monochromatic luminosity (L2500Å), and the X-ray weakness of a quasar is assessed via the deviation of its αOX value from that expected from this relation. We demonstrate the existence of a population of non-BAL X-ray-weak quasars, and the fractions of quasars that are X-ray weak by factors of ≥6 and ≥10 are 5.8% ± 0.7% and 2.7% ± 0.5%, respectively. We classify X-ray-weak quasars (X-ray weak by factors of ≥6) into three categories based on their optical spectral features: weak emission-line quasars (WLQs; C IV rest-frame equivalent width &lt; 16 Å), red quasars (Δ(g - i) &gt; 0.2), and unclassified X-ray-weak quasars. The X-ray-weak fraction of ${35}_{-9}^{+12} \% $ within the WLQ population is significantly higher than that within non-WLQs, confirming previous findings that WLQs represent one population of X-ray-weak quasars. The X-ray-weak fraction of ${13}_{-3}^{+5} \% $ within the red quasar population is also considerably higher than that within the normal quasar population. The unclassified X-ray-weak quasars do not have unusual optical spectral features, and their X-ray weakness may be mainly related to quasar X-ray variability.

Keywords: Active galaxies, X-ray quasars, Galaxy nuclei
Connecting Optical Morphology, Environment, and H I Mass Fraction for Low-redshift Galaxies Using Deep Learning. A galaxy's morphological features encode details about its gas content, star formation history, and feedback processes, which play important roles in regulating its growth and evolution. We use deep convolutional neural networks (CNNs) to learn a galaxy's optical morphological information in order to estimate its neutral atomic hydrogen (H I) content directly from Sloan Digital Sky Survey (SDSS) gri image cutouts. We are able to accurately predict a galaxy's logarithmic H I mass fraction, ${ \mathcal M }\equiv \mathrm{log}({M}_{{\rm{H}}{\rm\small{I}}}/{M}_{\star })$ , by training a CNN on galaxies in the Arecibo Legacy Fast ALFA Survey (ALFALFA) 40% sample. Using pattern recognition, we remove galaxies with unreliable ${ \mathcal M }$ estimates. We test CNN predictions on the ALFALFA 100%, extended Galaxy Evolution Explorer Arecibo SDSS Survey, and Nançay Interstellar Baryons Legacy Extragalactic Survey catalogs, and find that the CNN consistently outperforms previous estimators. The H I-morphology connection learned by the CNN appears to be constant in low- to intermediate-density galaxy environments, but it breaks down in the highest-density environments. We also use a visualization algorithm, Gradient-weighted Class Activation Maps, to determine which morphological features are associated with low or high gas content. These results demonstrate that CNNs are powerful tools for understanding the connections between optical morphology and other properties, as well as for probing other variables, in a quantitative and interpretable manner.

Keywords: Galaxies, Astronomy data modeling, Interstellar atomic gas, Galaxy environments, Neural networks, Convolutional neural networks, Astronomy data analysis, Galaxy evolution, Interstellar medium, Astronomy data visualization, Galaxy processes