Sazuna/UAT_keywords huggingface dataset:
A Machine Learning–ready Data Set for Exoplanet Atmospheric Retrieval. Atmospheric retrieval is a modeling technique used to determine a planet's atmosphere's temperature and composition from spectral data. The retrieved atmospheric composition can provide understanding into the surface fluxes of gaseous species necessary to maintain the stability of that atmosphere, leading to insights into the geological as well as biological processes active on the planet. Among exoplanets, rocky terrestrial ones are of particular interest because of their theoretical habitability. Atmospheric retrieval is both time consuming and computationally intensive. Traditional retrieval methods involve the use of complex algorithms that generate numerous atmospheric models. These models are then compared to observational data, and a posterior distribution is constructed to determine the most likely value and associated uncertainty for each model parameter. Runtimes scale with the number of model parameters, and when many molecular species are considered, become prohibitively long. The issue will become especially prohibitive as the number of detected exoplanets will grow tremendously in the near future. Machine learning (ML) offers a way to reduce the time to perform a retrieval by orders of magnitude, given a sufficient data set to train with. Here we present a large data set of 3,112,620 synthetic planetary systems generated with our Intelligent Exoplanet Atmospheric Retrieval framework based on the NASA Planetary Spectrum Generator. The data set contains the parameters defining each planetary system and the simulated spectra of stellar, planetary and noise components. The data set was designed to enable the first ML retrieval model for rocky terrestrial exoplanets, and it is publicly available through the NASA Exoplanet Archive.

Keywords: Astronomy databases, Distributed computing, Computational methods, Astrobiology, Biosignatures, Habitable zone, Exoplanet atmospheres
Unveiling the Emission Properties of Three Long-period Pulsars Using FAST. We detail the emission behaviors of three long-period pulsars detected using the Five-hundred-meter Aperture Spherical radio Telescope (FAST) during the Commensal Radio Astronomy FAST survey. Their rotational periods range from 1.83–4.75 s, and the null fractions (NFs) measure between 28% and 53%. PSR J1945+1211 and PSR J2323+1214 exhibited quasiperiodic nulls, with durations of around 57 s. The longest null was observed in PSR J1945+1211, lasting 76 s. PSR J2323+1214 displayed varying NFs between its leading and trailing components. For the first time in PSR J2323+1214, we detected five dwarf pulses, which are much weaker and narrower pulses than typical burst pulses. In addition, we investigate the microstructure of PSR J1900–0134 for the first time, revealing intricate pulses of up to 2.05 ms and noting its complex emission characteristics. Bright pulses occur in all of these sources at different rates. These observations suggest complex magnetospheric processes, potentially related to magnetic reconnections, and provide insights into the origins of bright and microstructure pulses, as well as their distinction from ordinary pulses.

Keywords: Pulsars, Radio pulsars
Synthetic Remote-sensing and In Situ Observations of Fine-scale Structure in a Pseudostreamer Coronal Mass Ejection through the Solar Corona. Coronal pseudostreamer flux systems have a specific magnetic configuration that influences the morphology and evolution of coronal mass ejections (CMEs) from these regions. Here we continue the analysis of the Wyper et al. magnetohydrodynamic simulation of a CME eruption from an idealized pseudostreamer configuration through the construction of synthetic remote-sensing and in situ observational signatures. We examine the pre-eruption and eruption signatures in extreme ultraviolet and white light from the low corona through the extended solar atmosphere. We calculate synthetic observations corresponding to several Parker Solar Probe–like trajectories at ∼10R⊙ to highlight the fine-scale structure of the CME eruption in synthetic WISPR imagery and the differences between the in situ plasma and field signatures of flank and central CME-encounter trajectories. Finally, we conclude with a discussion of several aspects of our simulation results in the context of interpretation and analysis of current and future Parker Solar Probe data.

Keywords: Solar flares, Solar magnetic reconnection, Interplanetary magnetic fields, Solar filament eruptions, Solar coronal mass ejections, Active solar corona, Solar coronal streamers
Machine Learning─based Photometric Redshifts for Galaxies in the North Ecliptic Pole Wide Field: Catalogs of Spectroscopic and Photometric Redshifts. We perform an MMT/Hectospec redshift survey of the North Ecliptic Pole Wide (NEPW) field covering 5.4 deg2 and use it to estimate the photometric redshifts for the sources without spectroscopic redshifts. By combining 2572 newly measured redshifts from our survey with existing data from the literature, we create a large sample of 4421 galaxies with spectroscopic redshifts in the NEPW field. Using this sample, we estimate photometric redshifts of 77,755 sources in the band-merged catalog of the NEPW field with a random forest model. The estimated photometric redshifts are generally consistent with the spectroscopic redshifts, with a dispersion of 0.028, an outlier fraction of 7.3%, and a bias of −0.01. We find that the standard deviation of the prediction from each decision tree in the random forest model can be used to infer the fraction of catastrophic outliers and the measurement uncertainties. We test various combinations of input observables, including colors and magnitude uncertainties, and find that the details of these various combinations do not change the prediction accuracy much. As a result, we provide a catalog of 77,755 sources in the NEPW field, which includes both spectroscopic and photometric redshifts up to z ∼ 2. This data set has significant legacy value for studies in the NEPW region, especially with upcoming space missions such as JWST, Euclid, and SPHEREx.

Keywords: Galaxy spectroscopy, Redshift surveys, Galaxies
Solar Cycle Prediction Using a Temporal Convolutional Network Deep-learning Model with a One-step Pattern. The human living environment is influenced by intense solar activity that exhibits periodicity and regularity. Although many deep-learning models are currently used for solar cycle prediction, most of them are based on a multistep pattern. In this paper a solar cycle prediction method based on a one-step pattern is proposed with the temporal convolutional network neural network model, in which historical data are input and only one value is predicted at a time. Through an autoregressive strategy, this predicted value is added to the input sequence to generate the next output. This process is iterated until the prediction of multiple future data is achieved. The experiments were performed on the 13 months–smoothed monthly total sunspot number data sourced from WDC-SILSO. The results showed that a one-step pattern fits solar cycles 20 to 25 well. The average fitting errors are mean absolute error = 1.74 and RMSE = 2.34. Finally, the intensity of solar cycle 25 was predicted with a one-step pattern. The peak was predicted to occur in 2024 October with a magnitude of 135.3 and end in 2030 November. By comparing the prediction results with other methods, our method is more reasonable and better than most methods. The codes are available on GitHub (https://github.com/zhaocui1207/solar-cycle-prediction-by-tcn) and Zenodo (doi:10.5281/zenodo.14211884).

Keywords: Solar cycle, Sunspot number
The Dispersion Measure and Scattering of Fast Radio Bursts: Contributions from Multicomponents, and Clues for the Intrinsic Properties. Fast radio bursts (FRBs) are luminous, millisecond-duration transients that offer great potential for probing the Universe, yet their physical origins remain unclear. The dispersion measure (DM) and scattering time (τ) distributions provide key insights into FRBs' properties, including source population, redshift, and energy distribution. We use a simplified model of FRB source population and intrinsic Schechter function–like energy distribution, coupled with a thorough assessment of various contributors to dispersion and scattering, to replicate the joint distribution of DM and τ in the CHIME/FRB catalog. A mixed FRB source population, including both young and old progenitors, is considered. Contributions to the DM and τ from the interstellar medium (ISM), circumgalactic medium (CGM) within the host, and foreground halos are informed by the IllustrisTNG simulation, while contributions from the Milky Way, intergalactic medium, and local environment are estimated by updated models. Using Markov Chain Monte Carlo simulations, we identify the optimal model that will reproduce the DM distribution and broadly reproduce the τ distribution in the CHIME/FRB catalog. Our model suggests that the fraction of FRBs tracing star formation rate is  , while   and   in the energy distribution function. Scattering predominantly arises from the circumburst medium or the ISM and CGM of hosts, which cause a DM of ∼10 pc cm‑3. Using our optimal model, we estimate FRB redshifts with two methods: DM-only and combined DM–τ. Evaluation with 68 localized FRBs reveals an rms error 0.11–0.12, and incorporation of τ has a minor effect. We further argue that the host galaxy properties of localized FRBs could be a potential tool to validate our model in the future.

Keywords: Intergalactic medium, Circumgalactic medium, Interstellar medium, Radio transient sources
The Interaction of a Supernova Remnant with Background Interstellar Turbulence. Supernova explosions are among the most energetic events in the Universe. After the explosion, the material ejected by the supernova expands throughout the interstellar medium (ISM), forming what is called a supernova remnant (SNR). The shocks associated with the expanding SNR are sources of galactic cosmic rays, which can reach energies of the PeV order. The magnetic field plays a key role in these processes. It is known that the ISM is turbulent, with an observed magnetic field of about a few μG, made by the superposition of a uniform and a fluctuating component. During the SNR expansion, the shock interacts with this turbulent environment, leading to a distortion of the shock front and a compression of the medium. In this work, we use the magnetohydrodynamics PLUTO code to mimic the evolution of the blast wave associated with an SNR. We perform a parametric study varying the level of density and magnetic field fluctuations in the ISM, with the aim of understanding the best parameter values able to reproduce real observations. We introduce a novel analysis technique based on a two-dimensional autocorrelation function C(ℓ) and a second-order structure function S2(ℓ), quantifying the level of anisotropy and the turbulence correlation lengths. By interpolating the autocorrelation function on a polar grid, we extract the power spectra of turbulence at the SNR. Finally, a preliminary comparison with Chandra observations of SN 1006 is also presented.

Keywords: Supernova remnants, Interstellar medium, Magnetohydrodynamical simulations
The 4–400 GHz Survey for the 32 Class II Disks in the Taurus Molecular Cloud. We have compiled the ∼4–400 GHz broad spectra of 32 Class II protoplanetary disks (PPDs) in the Taurus-Auriga region, which represents the brightest one-third of sources detected in the submillimeter band in this region. The spectra at &gt;20 GHz frequency can be described with a piecewise function: (1) a power law with a spectral index of ∼2 at &gt;200 GHz, (2) a power law with a spectral index in the range of 0.3–4.2 at 20–50 GHz, and (3) a transition region in between these two power laws, which can be characterized by a sigmoid function. This suggests that the flux densities at &gt;200 GHz and &lt;50 GHz are dominated by distinct emission components. At &gt;200 GHz, the emission is likely dominated by the optically thick dust thermal emission in the bulk of the disks. In some sources that were not detected at 6.8 GHz or 10 GHz, embedded high-density dust substructures may contribute to a significant fraction of the flux densities at 30–50 GHz, and the spectral indices are mostly consistent with 2.0. Although, at 30–50 GHz, free–free and/or synchrotron emission may be significant, and some sources in our sample have spectral indices &lt;2.0. Based on these results, we hypothesize that high-density dust substructures (e.g., vortices) are often found in resolved Class II PPDs, and are a precursor to the formation of kilometer-sized planetesimals and rocky planets. They may not present high contrast at &gt;200 GHz frequencies owing to the high optical depth. To probe these dust substructures, high angular resolution observations at &lt;100 GHz are necessary to distinguish them from free–free and synchrotron emission sources. Otherwise, in the analyses of the spatially unresolved spectra, one needs to simultaneously constrain the flux densities of free–free, synchrotron, and dust emission with the observations at ∼5–50 GHz.

Keywords: Circumstellar dust, Protoplanetary disks, Planet formation, Pre-main sequence
A Comparative Analysis of High-resolution Shock-capturing Schemes for Two-dimensional Magnetohydrodynamic Simulation of Flux Emergence in the Solar Atmosphere. This study presents a comparative analysis of high-resolution shock-capturing schemes in two-dimensional magnetohydrodynamic (MHD) simulations of magnetic flux emergence in the solar atmosphere. We evaluate four distinct reconstruction techniques based on recent improvements to the weighted essentially nonoscillatory (WENO) and targeted essentially nonoscillatory schemes. While these schemes have proven successful for the Euler equations of gas dynamics, their effectiveness in MHD simulations remains relatively unexplored. Our implementation combines the Harten–Lax–van Leer-discontinuities approximate Riemann solver for accurate flux computations, the generalized Lagrangian multiplier method for divergence control, and a third-order strong stability preserving the Runge–Kutta scheme for time integration. Numerical experiments reveal that these advanced schemes provide significant improvements in both accuracy and robustness in capturing complex MHD phenomena such as magnetosonic waves, MHD shocks, and magnetic buoyancy-driven instabilities. Among the tested methods, IMWENO-P proves to be the most physically consistent, effectively reproducing energy redistribution and compression patterns in line with theoretical predictions. These findings offer valuable insights into the strengths and limitations of each approach for simulating magnetic flux emergence dynamics.

Keywords: Solar physics, Solar magnetic fields, Magnetohydrodynamics, Magnetohydrodynamical simulations
Half a Million M Dwarf Stars Characterized Using Domain-adapted Spectral Analysis. We present fundamental atmospheric parameters (Teff and  ) and metallicities ([M/H]) for 507,513 M dwarf stars using low-resolution spectra (R ∼ 1800) from LAMOST DR10. By employing Cycle-StarNet, an innovative domain adaptation approach, we successfully bridge the gap between theoretical PHOENIX synthetic spectra and observed LAMOST spectra, enabling parameter measurements even for lower signal-to-noise (S/N) data (S/N &gt; 5). The fitting residual analysis shows a reduction from 2.0 times to 1.68 times the flux uncertainty. Comparing with available literature values, we find systematic offsets and precisions of 12 ± 70 K in Teff, −0.04 ± 0.17 dex in  , and −0.06 ± 0.20 dex in [M/H]. The precision improves for higher-quality spectra (S/N &gt; 50) to 47 K, 0.12 dex, and 0.14 dex respectively. The metallicity consistency between wide binaries shows a scatter of 0.24 dex, improving to 0.15 dex at S/N &gt; 50. We provide a comprehensive catalog including stellar parameters, spectral classifications, activity indicators, and binary/variability flags, establishing a resource for studies of the most numerous stellar population. The complete catalog can be accessed at doi:10.5281/zenodo.14030249.

Keywords: M dwarf stars, Catalogs, Fundamental parameters of stars, Spectroscopy
Generation of Cosmic-Ray Trajectories by a Diffusion Model Trained on Test Particles in 3D Magnetohydrodynamic Turbulence. Models for the transport of high-energy charged particles through strong magnetic turbulence play a key role in space and astrophysical studies, such as describing the propagation of solar energetic particles and high-energy cosmic rays. Inspired by the recent advances in high-performance machine learning techniques, we investigate the application of generative diffusion models to synthesizing test particle trajectories obtained from a turbulent magnetohydrodynamics simulation. We consider velocity increment, spatial transport, and curvature statistics, and find excellent agreement with the baseline trajectories for fixed particle energies. Additionally, we consider two synthetic turbulence models for comparison. Finally, challenges toward an application-ready transport model based on our approach are discussed.

Keywords: Interplanetary turbulence, Neural networks, Magnetohydrodynamics, Cosmic rays
On Type 1 Active Galactic Nuclei with Double-peaked [O III]. I. Data Sample and Basic Results. Double-peaked narrow emission lines (DPNELs) might be evidence for the existence of kiloparsec-scale dual active galactic nuclei (AGNs). There are so far large samples of objects with DPNELs in narrow emission-line galaxies. Here, a systematic search is made to build a sample of type 1 AGNs with double-peaked [O III] from Data Release 16 of the Sloan Digital Sky Survey (SDSS). Through visually inspecting and fitting [O III], fitting broad Hα emission lines, performing an F-test for [O III] profiles, and checking broad Hβ and [O III] emission lines, we select 62 type 1 AGNs with reliable double-peaked [O III] from 11,557 QSOs with z &lt; 0.3. After visually checking the 62 SDSS multicolor images, we find only seven objects with signs of merging. Four possible models for the double-peaked [O III] observed in our sample are discussed: the superposition model, AGN outflow model, dual AGN model, and rotating disk model. However, the current results cannot provide any one explanation conclusively, and additional observational data are needed to provide the details of the narrow-line regions. But at least 22 objects with different velocity offsets between double-peaked [O III] and narrow Hα emission lines could be excluded as dual AGN candidates. The relative velocity offsets of the [O III] blueshifted/redshifted components are negative to their line flux ratios, which is consistent with the dual AGN model. This work provides a new sample of 62 type 1 AGNs with double-peaked [O III] for further study.

Keywords: Supermassive black holes, Quasars, Active galaxies, Emission line galaxies, Active galactic nuclei
VLASS-based Survey of Transition State Galaxies and Their Relationship to Compact Peaked-spectrum Radio Sources. We present multifrequency and high-resolution studies of a sample of 24 radio transient sources discovered by comparing the NRAO VLA Sky Survey and the Very Large Array Sky Survey. All of them are characterized by a significant increase in radio flux density over the past two decades. Their convex spectra, small sizes, and high brightness temperatures are typical for young GHz-peaked spectrum (GPS) radio sources and indicative of an active galactic nucleus (AGN) buried in the host galaxy. On the other hand, they are much weaker than the archetypal GPS objects, and their parsec-scale radio structures, although indicating the presence of young radio jets, are similar to radio-quiet AGNs like Seyfert and low-ionization nuclear emission-line region galaxies. Based on the distribution of these objects in power‑size (P‑D) and peak frequency‑size (νp‑D) diagrams, we suggest that, after stabilizing their radio activity, some of the GHz-peaked radio transients (galaxies and quasars) will develop into radio-intermediate and radio-quiet quasars and low-frequency peaked-spectrum objects. We discuss several possible origins for the transient radio emission in our sources and conclude that changes in the accretion rate combined with low-power radio ejecta are the most probable cause. This is the scenario we also propose for one of our sources, 101841‑13, which was independently identified as a candidate tidal disruption event (TDE) based on its infrared variability. However, we cannot exclude that 101841–13 or other sources in our sample are TDEs.

Keywords: Active galaxies, Radio quiet quasars, Galaxy jets, Radio loud quasars, Radio galaxies, Active galactic nuclei, Galaxy evolution
Physical Parameters of 12,201 ASAS-SN Contact Binaries Determined by a Neural Network. In the era of astronomical big data, more than one million contact binaries have been discovered. Traditional approaches of light-curve analysis are inadequate for investigating such an extensive number of systems. This paper builds on prior research to present an advanced neural network model combined with the Markov Chain Monte Carlo algorithm and including spot parameters. This model was applied to 12,785 contact binaries selected from All-Sky Automated Survey for Supernovae. By removing those with a goodness of fit less than 0.8, we obtained the physical parameters of 12,201 contact binaries. Among these binaries, 4332 are A-subtype systems, while 7869 are W-type systems, and 1594 systems have mass ratios larger than 0.72 (H-subtype systems). A statistical study of the physical parameters was carried out, and we found that there are two peaks in the mass-ratio distribution and that the probability of the presence of spots is about 50%. In addition, the differences in flux between the two light maxima are from −0.1 to 0.1. As the orbital period and the temperature of the primary component decrease, the difference between the two light maxima becomes more pronounced. Based on the relationships between the transfer parameter and luminosity ratio, as well as between the luminosity ratio and mass ratio, we found that A-, W-, and H-type contact binaries are distributed in distinct regions.

Keywords: Eclipsing binary stars, Astronomy data analysis, Contact binary stars, Fundamental parameters of stars
Radiative Parameters of Odd-parity Levels in Sm III. Experimental radiative lifetimes for eight odd-parity levels belonging to 4f55d configurations of Sm III were measured by the time-resolved laser-induced fluorescence method. To our knowledge, the lifetimes for four out of the eight levels were measured for the first time. By combining our experimental lifetimes and the theoretical branching fractions derived from the Database on Rare Earths at Mons University, the transition probabilities and oscillator strengths for 23 Sm III lines were derived, two of which were reported for the first time.

Keywords: Atomic spectroscopy, Transition probabilities, Atomic physics, Radiative processes