Sazuna/UAT_keywords huggingface dataset:
νGAN: A Deep Learning Emulator for Cosmic Web Simulations with Massive Neutrinos. Understanding the impact of neutrino masses on the evolution of the Universe is a central goal of modern cosmology. Due to their large free-streaming lengths, neutrinos significantly affect structure formation at nonlinear scales, requiring accurate theoretical predictions to fully exploit current and future galaxy surveys. However, generating such predictions through large ensembles of cosmological simulations is computationally expensive. In this work, we introduce a deep learning-based generative adversarial network, νGAN, to emulate the Universe across a range of neutrino masses from 0.0 to 1.2 eV. The generated 2D cosmic web maps are statistically independent, show no correlations with the training data, and closely reproduce the matter distribution of true simulations. We validate the model through visual inspection and key cosmological and computer-vision statistics. Our results show that νGAN achieves ∼5% accuracy in the 2D power spectrum over the range 0.03 ≲ k ≲ 1 h Mpc−1. Scales k ≳ 0.5 h Mpc−1, corresponding to the fully nonlinear regime, exhibit increased scatter, reflecting the intrinsic difficulty of modeling highly nonlinear structure formation dominated by strong mode coupling and non-Gaussian features. While νGAN attains percent-level accuracy across linear and quasi-nonlinear scales and remains reliable up to k ≍ 1 h Mpc−1, improved fidelity in the deeply nonlinear regime is expected to require more expressive generative approaches, such as diffusion models. This work establishes a proof of concept for fast, scalable emulation of massive neutrino cosmologies, enabling large simulation ensembles and precision cosmological analyses. Future extensions will focus on higher-resolution 3D data and more advanced generative models.

Keywords: Large-scale structure of the universe, Neural networks, Cosmological parameters, Convolutional neural networks, N-body simulations, Astronomical simulations
Inferring Photospheric Horizontal Flows from Multiple Observations with SUVEL Models. Photospheric horizontal velocity fields play essential roles in the formation and evolution of numerous solar activities. Various methods for estimating the horizontal velocity field have been proposed in the past. Aiming at the highest available (and future) spatial resolution (10 km pixel−1) observations, a new method, the Shallow U-net models (SUVEL), based on realistic numerical simulation and machine learning techniques, was recently developed to track the photospheric horizontal velocity fields. Although SUVEL has been tested on numerical simulation data, its performance on solar observational data remained unclear. In this work, we apply SUVEL to the photospheric intensity observations from four ground-based solar telescopes (DKIST, GST, NVST, and SST) with the largest available apertures, and compare the results obtained from SUVEL with the Fourier local correlation tracking method (FLCT). Average correlation indices between granular regions and velocity fields inferred by SUVEL (FLCT) are 0.63, 0.81, 0.80, and 0.87 (0.00, 0.11, 0.16, and 0.10) for DKIST, GST, NVST, and SST observations. Higher correlation indices between the velocity fields tracked by SUVEL and granular patterns than FLCT reveal the superior performance of SUVEL, validating its reliability with respect to solar observational data.

Keywords: Solar granules, Solar observatories, Solar photosphere
On the Estimation of Sulfuric Acid Vapor Concentrations below the Venus Cloud Deck Using the Akatsuki Radio Science Experiment. We report new constraints on the vertical distribution of sulfuric acid vapor in the Venusian atmosphere, derived from a refined analysis of radio occultation (RO) data. The method estimates the power spectral density of the received signal, to recover both the signal intensity and the Doppler shift. The received signal power is estimated at a 1 s cadence, which enhances the sensitivity and detection of the signal at lower altitudes of Venus, even in regions of high atmospheric opacity. After correcting the total attenuation for refractive losses, absorption by known microwave absorbers is removed, leaving a residual signal attributable to sulfuric acid vapor. Two different methods of estimating the absorption due to sulfur dioxide have been presented, including one that incorporates in situ data, which should better constrain the sulfuric acid vapor abundance below the clouds. Retrieved profiles for altitudes of 40─50 km reveal an increasing vapor abundance to more than 10 ppm below the clouds and a sharp decline above 50 km, in line with the expected saturation profile. These measurements agree with current models of the Venusian cloud structure and composition, demonstrating that RO data—when coupled with optimized spectral analysis—can yield quantitative constraints on trace absorbers in optically thick atmospheres.

Keywords: Planetary atmospheres, Radio occultation, Venus
The Observation of Ground-level Enhancement GLE 77 by the Neutron Detectors of the Experimental Complex NEVOD. A ground-level enhancement (GLE) event was observed by neutron detectors designed for the registration of extensive air showers (EASs) at the Experimental Complex (EC) NEVOD. The potential for that was unlocked by a recent modernization of the experimental setup that included implementation of additional channels for measuring neutron flux variation. At 10:15 UT on 2025 November 11, a sudden and significant increase in the neutron flux was detected by two installations: PRISMA-36 and URAN arrays. For the first time, a GLE has been recorded using a set of neutron detectors oriented at the EAS studies. We present the measured EC NEVOD data and the results of the preliminary analysis of the observed GLE.

Keywords: Solar activity, Solar physics, Cosmic ray detectors, Cosmic ray showers
Analyzing Polycyclic Aromatic Hydrocarbons as a Tracer of Anomalous Microwave Emission near the Galactic Plane Using the COSMOGLOBE DIRBE Reduction. The physical mechanism producing anomalous microwave emission (AME) has been an unresolved puzzle for close to 30 yr. One candidate mechanism is rotational emission from polycyclic aromatic hydrocarbons (PAHs), which can have the necessary electric dipole moment and size distribution to account for the AME in representative interstellar environments. However, previous investigations have found that AME is better correlated with the far-infrared dust emission rather than the PAH emission. In this work, we analyze the correlations between the AME and the PAH and far-infrared dust emission using the 3.3 μm PAH emission feature as observed by band 3 of the Diffuse Infrared Background Experiment (DIRBE). This analysis builds on previous work conducted in individual molecular clouds and extends it into fainter, more diffuse structures. In addition, we utilize the COSMOGLOBE DIRBE reduction for this work, building on previous studies that used the original DIRBE dataset. We find that the AME is better correlated with far-infrared dust emission (ρ ∼ 0.9) than the PAH emission (ρ ∼ 0.7) in the central ∣b∣ ≤ 10° region of the sky. This could indicate either that non-PAH dust grains or an alternative physical emission mechanism is primarily responsible for the AME in the Galactic plane or that the excitation conditions for mid-infrared emission and for AME from PAHs differ substantially.

Keywords: Dust physics, Milky Way disk, Polycyclic aromatic hydrocarbons, Interstellar medium
Spin Frequency of Neutron Star in the Bright Atoll Source 4U 1705-44 Using NICER Observation. We conducted a systematic study of two thermonuclear type I X-ray bursts (B1 and B2) and the spectral properties of the bright atoll type neutron star low-mass X-ray binary 4U 1705−44 using NICER observation. In our analysis, a burst oscillation at ∼702 Hz was detected during the double-peaked profile of burst B1. This provides the first strong evidence for the spin frequency of the neutron star, which establishes 4U 1705−44 as a rapid rotator. The measured convexity parameters of the bursts indicate that both bursts likely ignited at off-equatorial latitudes. The ignition depth of burst B1 was nearly twice that of B2, indicating substantial fuel consumption between the two events. The recurrence time of B2 (∼1 hr) categorizes it as a short waiting time burst. The complementary spectral analysis of persistent emission, modeled with tbabs×(nthcomp+ diskbb), showed a hard state with a photon index Γ &lt; 1.12. The hardness─intensity diagram was consistent with the source being in the island state. Notably, the accretion disk appeared to extend close to the neutron star surface.

Keywords: Low-mass x-ray binary stars, Neutron stars, X-ray bursts, High energy astrophysics
A Practical Framework for Estimating the Repetition Likelihood of Fast Radio Bursts from Spectral Morphology. The repeating behavior of fast radio bursts (FRBs) is regarded as a key clue to understanding their physical origin, yet reliably distinguishing repeaters from apparent nonrepeaters with current observations remains challenging. Here we propose a physically interpretable and practically quantifiable classification framework based on spectral morphology. Using dimensionality reduction, clustering, and feature-importance analysis, we identify the spectral running r and spectral index γ as the most critical parameters for distinguishing repeaters from apparent nonrepeaters in the CHIME/FRB sample. In the γ─r space, repeaters preferentially occupy regions with steeper, narrower-band spectra, whereas nonrepeaters cluster in flatter, broader-band regions, resulting in a clear density separation. We further construct a probability map in the γ─r space based on Gaussian mixture model posterior analysis, revealing a clear gradient of repetition likelihood from ∼67% in the high-repetition region to ∼7% in the low-repetition region. This model also identifies several apparent nonrepeaters with high inferred repetition probability, highlighting them as priority targets for future monitoring. This framework provides a simple and generalizable tool for assessing repeatability in the CHIME/FRB sample and highlights the diagnostic power of spectral morphology in unveiling FRB origins.

Keywords: Radio bursts, Classification systems, Radio transient sources
Predicting Associations between Solar Flares and Coronal Mass Ejections Using SDO/HMI Magnetograms and a Hybrid Neural Network. Solar eruptions, including flares and coronal mass ejections (CMEs), have a significant impact on Earth. Some flares are associated with CMEs, and some flares are not. The association between flares and CMEs is not always obvious. In this study, we propose a new deep learning method, specifically a hybrid neural network (HNN) that combines a vision transformer with long short-term memory, to predict associations between flares and CMEs. HNN finds spatio-temporal patterns in the time series of line-of-sight magnetograms of solar active regions collected by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory and uses the patterns to predict whether a flare projected to occur within the next 24 hr will be eruptive (i.e., CME-associated) or confined (i.e., not CME-associated). Our experimental results demonstrate the good performance of the HNN method. Furthermore, the results show that magnetic flux cancellation in polarity inversion line regions may well play a role in triggering flare-associated CMEs, a finding consistent with the literature.

Keywords: Solar activity, Solar active regions, Solar flares, Solar coronal mass ejections
A Compact Object with a K-type Star Companion in the Solar Neighborhood: A Wide Postcommon Envelope Binary with a White Dwarf Candidate. Post-common envelope binaries (PCEBs) consisting of a white dwarf (WD) plus a main-sequence star can constrain current prescriptions of common envelope evolution (CEE) and calibrate theoretical models of binary formation and evolution. Most PCEBs studied to date have typical orbital periods of hours to a few days and can be well explained by assuming inefficient CEE to expel the envelope. However, there are currently several systems with relatively wide orbital periods (&gt;18 days). To explain these wide PCEBs, additional sources of energy have been suggested to be taken into account. Here, we present the discovery and observational characterization of a compact object (M ≥ 0.58 M⊙) with a K-type star companion in the solar neighborhood (d ∼ 112 pc) and an orbital period of Porb ∼ 14 days. The compact object binary is likely to be a system consisting of a WD and a barium dwarf, making it the shortest-period barium star binary candidate known. Such a system with an orbital period within the gap between tight and wide binaries provides a test of whether additional energy sources are required to explain its formation. Using binary evolution models, we investigate the evolutionary history of this wide PCEB system and find that the observed properties of this source can be explained without invoking any extra energy source.

Keywords: Compact binary stars
Metal Pipe: A Broadly Applicable Stellar Abundance Pipeline Using Isochronal Parameters. Characterizing exoplanet host stars at the population level requires a method of homogeneously characterizing stellar properties across all spectral types. To this end, we have developed Metal Pipe, a new code for determining stellar parameters and abundances, which is designed for use across a wider range of spectral types than many commonly used codes. It combines the widely used package MOOG with photometric stellar parameters, a user-supplied high-resolution spectrum, and a newly curated list of spectral lines. Metal Pipe outputs values for Teff,  log(g) , M*, R*, and L* from isochrones, and the abundances of C, O, Na, Mg, Al, Si, S, Ca, Ti, and Fe from MOOG. In this paper, we describe the Metal Pipe algorithm and tests of Metal Pipe against previous abundance measurements on archival HIRES spectra of 503 F-, G-, and K-type stars. We find rms scatter of ∼100 K in Teff, ∼0.10 dex in  log(g) , and ∼0.10 dex for all measured abundances. These values are comparable to the estimated measurement uncertainties, verifying Metal Pipe for continued use in building a detailed abundance catalog. Future papers in this series will test Metal Pipe's applicability to late-K and M dwarf stars, and provide other improvements.

Keywords: Stellar abundances, Exoplanets, Planet hosting stars
Constraining Nuclear Molecular Gas Content with High-resolution CO Imaging of GOALS Galaxies. We present measurements of the cool molecular gas mass around the nuclei of two gas-rich mergers, III Zw 035 and IRAS F01364−1042, whose enclosed masses (Menc) within the central 40─80 pc would be overmassive if attributed entirely to the supermassive black hole (SMBH) mass and compared to SMBH─galaxy scaling relations. Our gas mass measurements are derived from Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 long-baseline observations of CO(J = 2─1) and 230 GHz continuum emission at 14─20 pc resolution, which probes below the resolving limit of the previous black hole mass measurements. Subtracting molecular gas mass from these enclosed masses is not enough to reconcile with black hole─galaxy relationships, but independently measuring Menc using the cold CO(2─1) gas does shift the black holes down to their expected values. Still, these ALMA data reveal respective molecular gas masses of ∼3 × 107 to ∼6 × 108 M⊙ within 70 pc of these black holes, which could challenge some black hole accretion models that assume nuclear gas like this has no angular momentum.

Keywords: Molecular gas, Supermassive black holes, Active galactic nuclei, Galaxy mergers, Extragalactic astronomy
A Tale of Two Dust Disks in Our Milky Way. Cosmic dust plays a vital role in stellar and galactic formation and evolution, but its three-dimensional structure in the Milky Way has remained unclear due to insufficiently precise reddening and distance measurements. Although early studies typically adopted a single-disk model, we detect two distinct components at Galactocentric distances of 5─14 kpc, enabled by photometric, spectroscopic, and astrometric measurements of over 5 million stars. The thin dust disk's scale height increases radially from 60 to 200 pc, while the thick disk grows from 300 to 800 pc. For the first time, we find the thin and thick dust disks correlate spatially with the molecular and atomic hydrogen disks, respectively. The thin, thick, and combined disks have scale lengths of  9.6−1.1+1.2  ,  4.2−0.3+0.4  , and  6.6−0.3+0.3  kpc, respectively. The gas-to-dust ratio shows an exponential radial gradient, increasing from ∼60 at 5 kpc to ∼470 at 14 kpc. These findings provide new insights into dust morphology in the Galaxy and raise fundamental questions that require further investigation.

Keywords: Interstellar dust, Interstellar medium, Interstellar extinction, Milky Way Galaxy, Galaxies
ODIN: A New Lyα Blob Selection Method, Sample, and Statistical Analysis at z ∼ 3.1. Lyα blobs (LABs) are large, spatially extended Lyα-emitting objects whose nature remains unclear. Their statistical properties, such as number densities and luminosity functions, are still uncertain because of small sample sizes and large cosmic variance. The One-hundred-deg2 DECam Imaging in Narrowbands (ODIN) survey, with its large volume, offers an opportunity to overcome these limitations. We describe our LAB selection method and present 112 new LABs in the 9 deg2 E-COSMOS field. We begin with the conventional LAB selection approach, crossmatching Lyα-emitting galaxies with extended Lyα sources, yielding 89 LAB candidates. To obtain a more complete LAB sample, we introduce a new selection pipeline that models all galaxies detected in deep broadband imaging, subtracts them from the narrowband image, and then directly detects extended Lyα emission. This method successfully identifies 23 additional low-SB LABs, which could otherwise be missed by the conventional method. The number density of ODIN LABs near an ODIN protocluster (n = 7.5 × 10−5 cMpc−3) is comparable to that found in the SSA22 protocluster and is 4 times higher than the average across the field. The cumulative Lyα luminosity function within the protocluster regions is similar to that measured for the LABs in the SSA22 protocluster, suggesting a large excess of luminous LABs relative to the average field. These findings suggest the Lyα luminosities and number densities of LABs are environment-dependent. ODIN will provide an expansive LAB and protocluster samples across six additional fields and two more redshifts, allowing us to investigate the nature of LABs in relation to their environments.

Keywords: High-redshift galaxy clusters, Circumgalactic medium, Intergalactic medium, Lyman-alpha galaxies, Galaxies
A Comoving Framework for Planet Migration. The migration of planets within their nascent protoplanetary disks is a fundamental process that shapes the final architecture of planetary systems. However, studying this phenomenon through direct hydrodynamical simulations is computationally demanding, with traditional methods on fixed grids being ill-suited for tracking planet migration over long timescales due to their high cost and limited domain. In this work, we present a self-consistent comoving framework designed to overcome these challenges. Our method employs a coordinate transformation that scales with the planet's evolving semimajor axis, keeping the planet stationary with respect to its local computational grid. This transforms the standard hydrodynamic equations by introducing a source term that accounts for the inertial forces of the noninertial reference frame. We implement this framework in the FARGO3D code and validate it through a benchmark test, demonstrating excellent agreement with conventional fixed-grid simulations until the latter are compromised by boundary effects. Our analysis shows that, for long-range migration scenarios, the comoving method can be over an order of magnitude more computationally efficient, dramatically reducing the cost of simulating migrating planets and making secular timescale simulations computationally feasible. This framework serves as both a powerful numerical and theoretical tool, simplifying the time-dependent flow around a migrating planet that offers clearer physical insight. It enables long-term, self-consistent studies of planet─disk interaction, representing a crucial step toward performing planet population synthesis based on full hydrodynamical simulations.

Keywords: Hydrodynamical simulations, Exoplanet migration, Hydrodynamics, Planetary system formation, Protoplanetary disks, Astrophysical fluid dynamics, N-body simulations, Planet formation
An Accretion Flare Interpretation for the Ultra-high-energy Neutrino Event KM3-230213A. We study the origin of the ultra−high-energy (UHE) neutrino event KM3-230213A detected by KM3NeT, focusing on MRC 0614−083, which has been pinpointed as the closest blazar to the neutrino localization exhibiting variable multiwavelength emission. A joint interpretation of the optical, infrared, and X-ray light curves suggests that MRC 0614−083 has undergone a super-Eddington accretion flare accompanied by efficient proton acceleration. That flare has initiated a delayed infrared echo within the surrounding dust torus, which serves as a target for photomeson (pγ) interactions such that a self-consistent picture emerges that complements the blazar jet scenario: the predicted UHE neutrino flux is at the level expected from a joint E−2 fit with the IceCube measurements at lower energies, the variable nature of the event alleviates the tension with IceCube limits, and the accompanying electromagnetic cascade describes the X-ray flare around the neutrino detection time. Since a key remaining uncertainty is the unknown redshift of the source, we strongly encourage optical/ultraviolet spectroscopic measurements to determine its redshift.

Keywords: Neutrino astronomy, Active galaxies
Fraction of Energy Carried by Coherent Structures in the Turbulent Cascade in the Solar Wind. Turbulence is prevalent in astrophysical plasma flows. Both wave─wave interactions and coherent structures offer mechanisms to mediate turbulent cascades. Solar Orbiter in situ satellite observations of plasma turbulence in the solar wind are used to determine the percentage of the power in the turbulent cascade carried by coherent structures, and its anisotropy. In the inertial range of magnetohydrodynamic turbulence, this percentage increases with increasing frequency, up to a maximum of ∼50% just below the scale break where the kinetic range begins. The percentage then decreases with increasing frequency in the kinetic range. The behavior is most ordered at solar distances &lt;0.4 au with evidence of two subranges in the inertial range at distances beyond this. The energy carried in coherent structures may ultimately heat the solar wind.

Keywords: Space plasmas, Magnetohydrodynamics, Heliosphere, Interplanetary turbulence, Solar wind, Time series analysis