Sazuna/UAT_keywords huggingface dataset:
Gravitational Lenses in UNIONS and Euclid (GLUE). I. A Search for Strong Gravitational Lenses in UNIONS with Subaru, CFHT, and Pan-STARRS Data. We present the results of our pipeline for discovering strong gravitational lenses in the ongoing Ultraviolet Near-Infrared Optical Northern Survey (UNIONS). We successfully train a deep residual convolutional neural network based on CMU-Deeplens architecture, which is designed to detect strong lenses in ground-based imaging surveys. We train on images of real strong lenses and deploy on a sample of 8 million galaxies in areas with full coverage in the g, r, and i filters—the first multiband search for strong gravitational lenses in UNIONS. Following human inspection and grading, we report the discovery of a total of 1346 new strong-lens candidates, of which 146 are Grade A, 199 are Grade B, and 1001 are Grade C. Of these candidates, 283 have lens galaxy spectroscopic redshifts from the Sloan Digital Sky Survey, and an additional 297 have them from the Dark Energy Spectroscopic Instrument Data Release 1. We find 15 of these systems display evidence of both lens and source galaxy redshifts in spectral superposition. We also report the spectroscopic confirmation of seven lensed sources in high-quality systems, all with z &gt; 2.1, using the Keck Near Infrared Echellette Spectrograph and the Gemini Near-Infrared Spectrograph.

Keywords: Galaxy spectroscopy, Strong gravitational lensing, Convolutional neural networks, Sky surveys
Multiwavelength Variability and Jet Properties of Low-synchrotron-peaked BL Lacertae Objects. Low-synchrotron-peaked BL Lac objects (LBLs) are promising candidates for masquerading BL Lacs, and the mechanism responsible for their high-energy γ-ray emission still requires further investigation. In this paper, we conduct detailed analyses of the variability and spectral properties of a sample of LBLs, utilizing 16 yr of multi-instrument observations spanning from 2008 October to 2024 September. To understand the physical properties of LBLs, we model their broadband, nearly simultaneous spectral energy distributions during different variability episodes using a one-zone leptonic scenario. The major outcomes can be outlined as follows. (1) The broadband spectra of LBLs can be reproduced within a leptonic model framework incorporating seed photons from both the broad-line region (BLR) and the dusty torus (DT). The γ-ray emission is inferred to be generated in the location beyond the BLR and within the DT. (2) For an e±─p jet, the jet power of LBLs follows the relation  Pe'  (the kinetic power carried in relativistic electrons) ∼  Pp'  (the kinetic power in cold protons) &gt;  Prad'  (the radiation)  &gt;PB''  (Poynting flux). (3) The LBL radiation mechanism during multiwavelength simultaneous flares can be described by a one-zone leptonic model, while peculiar orphan X-ray flares are more plausibly explained by a stochastic dissipation scenario.

Keywords: Blazars, Non-thermal radiation sources, Jets
Resonant Scattering of the He I 1.0833 μm Triplet in H II Regions: Emission Spectra. Resonant scattering of He I 1.0833 μm triplet photons by metastable He 2 3S1 is studied for optical depths characteristic of H II regions. Regions with large He 2 3S1 column densities are predicted to have unusually broad multipeaked 1.0833 μm emission profiles, with the centroid blueshifted by up to ∼14 km s−1 relative to other lines. The feature FWHM can exceed 100 km s−1 for some regions. Resonant trapping enhances dust absorption and reduces the He I 1.0833 μm emission. Care must be taken when using the He I 1.0833 μm/H I 1.0941 μm (Paγ) ratio to estimate the He+/H+ ratio. Predicted spectra are computed for examples, including M17-B and NGC 3603 in the Galaxy, and a star-forming region in M51. Observations of the 1.0833 μm triplet with spectrometers such as NIRSPEC, CARMENES, or X-Shooter can confirm the predicted effects of resonant scattering in H II regions, and constrain the nebular conditions.

Keywords: H II regions, Radiative transfer, Interstellar medium
Multiband ALMA Polarization Observations of BHB 07-11 Reveal Aligned Dust Grains in Complex Spiral Arm Structures. Polarization-mode observations from the Atacama Large Millimeter/submillimeter Array (ALMA) are powerful tools for studying the dust grain populations in circumstellar disks. Many sources exhibit polarization signatures consistent with aligned dust grains, yet the physical origin of this alignment remains uncertain. One such source is BHB 07-11, a Class I protobinary object in the Pipe Nebula with complex spiral arm structures in its circumbinary disk. While magnetic fields are often invoked to explain grain alignment in the interstellar medium, the contrasting conditions in circumstellar disk environments demand further investigation into grain alignment mechanisms. To determine BHB 07-11's dominant polarization mechanism, we leverage ALMA polarization-mode dust continuum observations in Bands 3 (λ = 3.1 mm), 6 (λ = 1.3 mm), and 7 (λ = 0.87 mm), in combination with high-resolution dust continuum and spectral line observations in Band 6. Observed polarization vectors in each band are consistent with emission from aligned grains and follow the structure of the spiral arms as shown in the high-resolution observations. Given the relationship between the observed polarization vector orientation and the spiral arms, we find that the polarization morphology is most consistent with grains aligned through a relative velocity flow between gas and dust in the spiral arms, as envisioned in the recently developed badminton birdie-like alignment mechanism, rather than alignment with a magnetic field or other known alignment mechanisms.

Keywords: Binary stars, Circumstellar disks, Circumstellar dust, Radio interferometry, Polarimetry
A Comprehensive Interpretation of Fermi-LAT Pulsars: Fundamental-plane Death Border, Visibility Thresholds, and GeV─TeV Unification. We present a framework that links equatorial-current-sheet (ECS) physics to catalog-level, phase-averaged gamma-ray pulsar properties. Guided by analytic scalings and particle-in-cell (PIC) simulations, we show that the pulsar "Fundamental Plane" (relating gamma-ray luminosity, spectral cutoff energy, spin-down power  Ė , and surface magnetic field) is bounded by two regimes: a radiation-reaction-limited branch and a potential-drop-limited branch. Their intersection defines a transition in  Ė  that maps to a gamma-ray visibility threshold on the P─ Ṗ  diagram, above which detectability is set by distance and beaming, and below which both cutoff energy and efficiency decline rapidly. Placing ATNF pulsars and McGill magnetars onto these planes reproduces the observed Fermi occupancy, with millisecond pulsars (MSPs) on the observable side, young pulsars (YPs) straddling the threshold, and magnetars clustering at or just below it. At higher  Ė , both MSPs and YPs depart from the maximal radiation-reaction-limited envelope at similar cutoff energies, suggesting that enhanced pair creation screens the accelerating electric field in the ECS. We interpret this behavior with a compactness-based criterion for optically thin γγ pair feedback in or near the ECS and briefly note an extension to γγ → μ± that could yield pulsed multi-TeV neutrinos in the most energetic systems. The framework predicts a MeV-bright, GeV-faint corridor below Fermi sensitivity, a target for next-generation MeV missions. Finally, motivated by the recent HESSII detection of pulsed multi-TeV emission from Vela, we use PIC particle distributions with a seed-photon model to reproduce a multi-TeV inverse-Compton component alongside the GeV curvature emission, supporting a unified ECS-based GeV─TeV origin.

Keywords: Neutron stars, Gamma-ray observatories, Non-thermal radiation sources, Radiative processes, Gamma-ray astronomy, Astronomical simulations, Magnetohydrodynamical simulations
The Solar Origin and Life Project: Detailed Characterization of Candidates for the Zero Age Main-sequence and Subgiant Stages. The context of the Sun in the Galactic neighborhood is not well understood, especially when we compare its physical properties to those of nearby stars. Thereby, we still cannot fully comprehend whether or not the Sun is a typical star. This work aims to identify and characterize stars aligned with the solar evolutionary track that could represent it at the zero age main-sequence and subgiant stages. We performed a spectroscopic analysis of 18 photometrically selected candidates using high-resolution and high-signal-to-noise ratio spectra as well as the classical spectroscopic method, based on the excitation and ionization equilibria of Fe I and Fe II lines. Additionally, we derived evolutionary parameters using isochrones, and kinematic parameters. We also estimated chromospheric activity levels and performed age estimates through three additional independent methods: activity─age relations using the Ca II H and K and Hα lines, and rotation periods estimated from TESS light curves. We identified three candidates that provide a good match to the Sun at ≍ 0.5 Gyr (HD 13531 and HD 61033) and subgiant (HD 148577) stages. Moreover, HD 197210 could be of interest when studying the Sun at ≍2 Gyr, when the Earth's atmosphere started having a significant amount of oxygen. Our selection method was successful, and we were able to identify stars similar to the Sun at different evolutionary stages, which is essential for future research in the search of exoplanets, and understand habitability, especially with the advent of the next generation of exoplanet-hunting instruments.

Keywords: Fundamental parameters of stars, Solar analogs, Solar neighborhood, Solar evolution
A Simulation Study of an HFA-like Event at Mars. Hot flow anomalies (HFAs) are transient structures at planetary bow shocks characterized by hot, tenuous plasma. At Mars, where no global dipole field exists, such events interact with the induced magnetosphere in a unique and poorly understood way. This study employs a three-dimensional multifluid magnetohydrodynamic model to simulate an HFA-like event and assess its effects on the Martian plasma environment. The simulation reproduces key HFA characteristics, including outward bow-shock expansion, plasma density depletion accompanied by temperature enhancement, and the formation of shocks at the leading and trailing edges. The event causes ionopause uplift due to reduced solar wind dynamic pressure and erosion of the pileup magnetic field. Within the HFA core, a distinct vortex flow with a sunward component and the roll-up of the pileup magnetic field into the magnetosheath are observed. Although HFAs are typically associated with quasi-parallel shocks, our results show that a low-density solar wind slab interacting with a nearly perpendicular bow shock can also generate HFA signatures at Mars. This finding extends HFA formation mechanisms to unmagnetized planetary magnetospheres.

Keywords: Planetary magnetospheres, Mars, Planetary bow shocks
Direct Measurement of <SUP>59</SUP>Cu(p,α)<SUP>56</SUP>Ni Precludes a Strong NiCu Cycle in Type-I X-Ray Bursts. Model-observation comparisons of type-I X-ray bursts (XRBs) can reveal the properties of accreting neutron star systems, including the neutron star compactness. XRBs are powered by nuclear burning, and a handful of reactions have been shown to impact the model results. Reactions in the NiCu cycles, featuring a competition between 59Cu(p,γ)60Zn and 59Cu(p,α)56Ni, have been shown to be among the most important reactions as they are a critical checkpoint in rp-process flow and significantly impact the light curves and burst ashes. We report a direct measurement of 59Cu(p,α)56Ni, bringing stringent constraints on this reaction rate. New results rule out a strong NiCu cycle in XRBs, with a negligible degree of recycling, ≤5% up to 1.5 GK. The new reaction rate, when varied within new uncertainty limits, shows no impact on one-zone XRB model light curves tailored for clocked-burster GS1826─24, hence removing an important nuclear physics uncertainty in the model-observation comparison.

Keywords: Nuclear astrophysics, Explosive nucleosynthesis, X-ray bursts
Introducing RAFIKI: Refining Active Galactic Nuclei Feedback in Kinetic Implementations. Modern cosmological simulations have matured to the point of reproducing realistic galaxy populations across cosmic time. Yet these simulations rely on feedback from active galactic nuclei (AGN) to quench massive galaxies, and the details of this process remain poorly understood. To address this issue, we introduce Refining AGN Feedback in Kinetic Implementations (RAFIKI), a novel suite of simulations built upon SIMBA-C that varies the energetic efficiencies of jets and winds driven by AGN. Unlike the fiducial SIMBA-C simulation, RAFIKI separates the efficiencies of these two feedback modes, enabling a detailed study of their impact on galaxies, black holes, and the circumgalactic medium. We find that even with enhanced mass loading, the lower-velocity quasar-type wind mode cannot quench massive galaxies. However, it plays a significant role in regulating black hole growth and star formation in intermediate-mass galaxies. We also uncover degeneracies in the parameter space that highlight the lack of current constraints on AGN feedback. RAFIKI provides a controlled framework to disentangle these degeneracies using current and upcoming observations.

Keywords: Hydrodynamical simulations, Active galactic nuclei, Galaxy evolution, Circumgalactic medium, Extragalactic astronomy
Unveiling SN 2022eyw: A Bright Member of the Type Iax Supernova Subclass. We present comprehensive photometric and spectroscopic observations of SN 2022eyw, a luminous member of the Type Iax supernova (SN Iax) subclass. SN 2022eyw reached a peak absolute magnitude of Mg = ─17.80 ± 0.15 mag and exhibited a rise time of ∼15 days, placing it among the brighter Iax events. The bolometric light curve indicates a synthesized 56Ni mass of 0.11 ± 0.01 M⊙, with an estimated ejecta mass of 0.79 ± 0.09 M⊙ and kinetic energy of 0.19 × 1051 erg. The spectral evolution from −8 to +110 days past maximum reveals features characteristic of bright SNe Iax, including a transition from Fe III to Fe II dominance, moderate expansion velocities, and a lack of strong C II absorption. TARDIS spectral modeling of the early-phase spectra indicates well-mixed ejecta dominated by Fe-group elements. In addition, traces of unburnt carbon are detected, pointing to incomplete burning as expected in pure deflagration models. The late-time spectral evolution shows a blend of permitted and forbidden lines. Comparison with deflagration models suggests that SN 2022eyw originated from a partial deflagration of a Chandrasekhar-mass white dwarf, with explosion properties intermediate between the N3-def and N5-def models. These observations support pure deflagration of a CO white dwarf as a viable explosion mechanism for its luminous members.

Keywords: White dwarf stars, Type Ia supernovae, Photometry, Spectroscopy, Supernovae
Solar Wind Forecasting for Long-term Variations of the Global Heliosphere. The large-scale dynamics of the heliosphere is driven by solar activity and variable solar wind (SW) conditions. In situ SW observations inform time-dependent heliosphere modeling efforts but are only available up until the present day, thus restricting informed predictions to the very near future. We developed and implemented a method to provide long-term forecasting of SW parameters at 1 au. Such forecasting supports modeling efforts of the time-dependent global heliosphere by providing realistic boundary conditions for heliospheric models at the upwind model-domain boundary ahead of time in order to understand the global dynamic processes in the heliosphere such as the evolution of the termination shock (TS), heliosheath, and heliopause. Such forecasting capabilities are needed to better constrain the timing of New Horizons' TS encounter and predict energetic neutral atom flux variation for IMAP. We analyzed SW direct measurement time series for periodicities at various timescales using Lomb─Scargle periodogram analysis. Based on identified prominent periodicities, we construct quasiperiodic functions for the SW parameters. By extrapolating these functions forward in time, we obtain a prediction of the SW evolution over the next two solar cycles. Our results indicate that the next pulse in the SW dynamic pressure, which controls the global heliosphere, will occur around 2035.

Keywords: Solar cycle, Heliosphere, Termination shock, Solar wind, Bootstrap, Lomb-Scargle periodogram
Impact of Coronal Mass Ejection-driven Enhanced Magnetic Pressure on the Martian Northern Hemispheric Ionosphere during 2024 May 17─18. The Martian northern hemisphere (NH) is relatively devoid of ambient magnetic fields compared to the southern hemisphere (SH), which houses the strong crustal field regions. On 2024 May 17, when Mars was hit by a coronal mass ejection (CME), the periapsis of NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft was entirely in the NH. The dynamic pressure in the ionosphere was enhanced by almost 2 orders of magnitude during the Mars─CME interaction, allowing penetration of solar origin magnetic fields into the Martian ionosphere. Even at altitudes below 500 km, the ratio of magnetic pressure (Pb) to ionospheric thermal pressure (Pth) was amplified more than 100 times, creating an overpressure (OP) regime. This OP condition exposed the topside ionosphere to the CME. The topside ionosphere was severely depleted, with the electron (ne) and  O2+  ( nO2+ ) densities being reduced by nearly 50%─100%. The effects were particularly severe at altitudes above 350 km. The dayside ionosphere showed relatively stronger depletion compared to the terminator regions.

Keywords: Planetary ionospheres, Mars, Interplanetary magnetic fields, Solar coronal mass ejections, Solar storm, Magnetic storms
Spectroscopic Signatures and Photochemical Stability of the ClSO<SUB>3</SUB> and ClOSO<SUB>2</SUB> Radicals: New Benchmarks for Atmospheric and Astrochemical Models. Chlorine─sulfur oxides represent potentially important yet largely uncharacterized intermediates in atmospheric and astrochemical environments, from explosive volcanic plumes to irradiated exoplanet atmospheres and the sulfur-rich exospheres of Io and icy moons. Here, we present the first comprehensive structural, spectroscopic, and energetic characterization of the ClSO3 and ClOSO2 radicals. Using a hierarchy of high-accuracy composite quantum-chemical approaches—including CCSD(T)-F12, core─valence corrections, dual-level anharmonic force fields, and multireference excited-state treatments—we determine equilibrium geometries, rotational and vibrational spectra, vertical excitation energies, and photodissociation thresholds. ClSO3 is found to be substantially more stable than the ClOSO2 isomer, whose dissociation into ClO + SO2 is nearly thermoneutral, indicating that it may act as a short-lived but chemically relevant intermediate. Strong IR features in the 600─1200 cm−1 region, together with broad electronic absorption, show that both radicals can affect UV/visible opacity and photochemistry in chlorine- and sulfur-bearing environments. The predicted dipole moments and rotational constants place several intense transitions within Atacama Large Millimeter/submillimeter Array and NOEMA frequency ranges, making these species promising targets for future astronomical searches. The benchmark dataset reported here provides the spectroscopic foundation required for laboratory identification and enables the incorporation of halogen─sulfur intermediates into atmospheric, planetary, and interstellar chemical networks.

Keywords: Venus, Astrochemistry
Dynamics of Slow Solar Wind Emerging from an Equatorial Coronal Hole. We present a three-dimensional reduced magnetohydrodynamics model to depict turbulence induced by Alfvén waves within the slow solar wind originating from an open magnetic field positioned in a coronal hole near the solar equator. The nonlinear interactions between outward- and inward-propagating waves result in turbulence. As part of this investigation, we examine the conditions prevailing in an equatorial coronal hole using the interplanetary scintillation (IPS) observations. From IPS observations, we measure the magnetic field and velocity, both input parameters of our Alfvén wave turbulence model. We show the conditions of equatorial corona, a contributor to the slow solar wind, can generate Alfvén wave turbulence that accelerates and energizes the slow wind.

Keywords: Slow solar wind, Solar wind, Alfven waves
The AURORA Survey: Multiple Balmer and Paschen Emission Lines for Individual Star-forming Galaxies at z = 1.5─4.4. I. A Diversity of Nebular Attenuation Curves and Evidence for Non-unity Dust Covering Fractions. We present the nebular attenuation curves and dust covering fractions for 24 z = 1.5─4.4 star-forming galaxies using multiple Balmer and Paschen lines from the JWST/AURORA survey. Nebular reddening derived from Paschen lines exceeds that from Balmer lines for at least half the galaxies in the sample when assuming the commonly adopted Galactic extinction curve, implying the presence of heavily reddened star formation. The nebular attenuation curves exhibit a broad range of normalizations (RV ≃ 3.2─16.4). Motivated by the offsets in reddening deduced from the Balmer and Paschen lines, as well as the high RV values for the individual nebular attenuation curves, both of which suggest variations in the dust─star geometry, we propose a model with a sub-unity dust covering fraction (fcov). Fitting such a model to the H I recombination line ratios indicates fcov ∼ 0.6─1.0. The normalizations of the nebular attenuation curves, RV, are driven primarily by fcov and the mix of reddened and unreddened OB associations. Thus, the diversity of nebular attenuation curves can be accommodated by assuming dust grain properties similar to that of Milky Way sightlines but with a sub-unity covering fraction of dust. Integrated measurements of multiple Balmer and Paschen lines can be used to place novel constraints on the dust covering fraction towards OB associations. These, in turn, provide new avenues for exploring the role of the dust and gas covering fractions in a number of relevant aspects of high-redshift galaxies, including the impact of stellar feedback on ISM porosity and the escape of Lyα and Lyman continuum radiation.

Keywords: Interstellar dust extinction, Star formation, Galaxy evolution, Interstellar medium, High-redshift galaxies