Sazuna/UAT_keywords huggingface dataset:
DUALZ—Deep UNCOVER-ALMA Legacy High-Z Survey. We present the survey design and initial results of the Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 9 program of DUALZ, which aims to establish a joint ALMA and JWST public legacy field targeting the massive galaxy cluster A2744. DUALZ features a contiguous  4'×6'  ALMA 30 GHz-wide mosaic in Band 6, covering areas of μ &gt; 2 down to a sensitivity of σ = 32.7 μJy. Through a blind search, we identified 69 dust continuum sources at a signal-to-noise ratio (SNR) ≳ 5.0 with median redshift and intrinsic 1.2 mm flux of z = 2.30 and  S1.2mmint=0.24  mJy. Of these, 27 have been spectroscopically confirmed, leveraged by the latest NIRSpec observations, while photometric redshifts are also constrained by the comprehensive Hubble Space Telescope (HST), NIRCam, and ALMA data sets for the remaining sources. With priors, we further identify a [C II]158 μm line emitter at z = 6.3254 ± 0.0004, confirmed by the latest NIRSpec spectroscopy. The NIRCam counterparts of the 1.2 mm continuum exhibit undisturbed morphologies, denoted either by disk or spheroid, implying the triggers for the faint millimeter emission are less catastrophic than mergers. We have identified eight HST-dark galaxies (F150W &gt; 27 mag, F150W − F444W &gt; 2.3) and two JWST-dark (F444W &gt; 30 mag) galaxy candidates among the ALMA continuum sources. The former includes face-on disk galaxies, hinting that substantial dust obscuration does not always result from inclination. We also detect a marginal dust emission from an X-ray-detected galaxy at zspec = 10.07, suggesting an active coevolution of the central black hole and its host. We assess the infrared luminosity function up to z ∼ 10 and find it is consistent with predictions from galaxy formation models. To foster diverse scientific outcomes from the community, we publicly release reduced ALMA mosaic maps, cubes, and the source catalog at https://jwst-uncover.github.io/DR2.html#DUALZ.

Keywords: Starburst galaxies, Galaxy formation, Infrared spectroscopy, Astrosphere interstellar medium interactions, Millimeter-wave spectroscopy, Galaxy evolution, High-redshift galaxies
Orbital Parameters of 665 Double-lined Spectroscopic Binaries in the LAMOST Medium-resolution Survey. The period, mass ratio, eccentricity, and other orbital parameters are fundamental for investigating binary star evolution. However, the number of binaries with known orbital parameters remains limited. Utilizing the LAMOST medium-resolution spectroscopic survey, we derived orbital solutions for 665 SB 2 binaries by fitting the radial velocities of 1119 SB 2 systems with at least six observations, employing a modified version of The Joker optimized for SB 2 binaries. To ensure the reliability of the results, four selection criteria were applied: reduced chi-square, normalized mean absolute error, maximum phase gap, and radial velocity distribution metric. After applying these criteria, 665 reliable orbits were retained. Comparison with Kepler, TESS, and Zwicky Transient Facility light-curve data shows excellent agreement, with discrepancies in some cases attributed to shorter pulsation periods observed in light curves. Additionally, good consistency is found between our periods and those of SB 1 systems in Gaia data. These orbital solutions contribute to understanding binary star evolution and the statistical properties of binary populations.

Keywords: Multiple stars, Orbital elements, Periodic orbit, Astronomy data analysis, Spectroscopic binary stars, Radial velocity
Exoplanets in the Antarctic Sky. V. The Second Data Release of AST3-II/CHESPA and Newly Found Variables within the Southern Continuous Viewing Zone of TESS. Located at Dome A, the highest point on the Antarctic plateau, China's Kunlun station is a premier ground-based photometric observatory. Its cold, dry, and stable atmosphere allows continuous observation for over 40 days during polar winter, ideal for detecting short-period transiting exoplanets. Since 2008, the Antarctic Survey Telescopes (AST3) project has pursued the CHESPA program to search for exoplanet candidates. During the austral winters in 2016 and 2017, the AST3-II telescope surveyed fields located in the southern continuous viewing zone of the Transiting Exoplanet Survey Satellite (TESS). This paper presents the second data release from CHESPA, encompassing photometric data for over 85,000 bright (mi ≤ 15) stars. The survey achieved a photometric precision of approximately 2 mmag at optimal brightness levels. To illustrate the data quality, we present a catalog of 203 newly identified variable stars showing brightness variations over 5 mmag based on the 2017 observations, as compared to Data Release 1. Among these, 26 are newly recognized periodic variables that are not listed in the AAVSO database (https://www.aavso.org/), and 86 are in the TESS Candidate Target List. These variables required rigorous examination to eliminate false-positive signals in the transiting exoplanets search.

Keywords: Photometric systems, Sky surveys, Binary stars, Astrometric exoplanet detection, Eclipsing binary stars, Catalogs
Hemispheric Distribution of Solar Active Regions during Solar Cycles 23–25. Solar active regions (ARs) are crucial for understanding the long-term evolution of solar activities and predicting eruptive phenomena, including solar flares and coronal mass ejections. However, the cycle-dependent properties in the north–south asymmetry of ARs are not fully understood. In this study, we investigate the hemispheric distribution of ARs from Carrington rotations 1909–2278 (between 1996 May and 2023 November) by using three parameters that describe the magnetic field distribution of ARs: number, area, and flux. The main findings are as follows: (1) The three AR parameters show significant hemispheric asymmetry in cycles 23–25. The strong correlation between the AR area and flux indicates that they can better reflect the intrinsic properties of the solar magnetic field. (2) The correlation between sunspot activity and AR parameters varies in the two hemispheres across the different cycles. The AR parameters provide additional information for the variations in sunspot activity, which can better predict the intensity and cyclical changes of solar activity. (3) The variation in the fitting slope sign of the asymmetry index for AR parameters reflects periodic changes in hemispheric ARs, providing valuable insights into the activity of other stars. (4) Both the dominant hemisphere and the cumulative trend of AR parameters display a cycle-dependent behavior. Moreover, the trend variations in the AR area and flux are similar, reflecting the long-term evolutionary characteristics of the solar magnetic field. Our analysis results are relevant for understanding the hemispheric coupling of solar magnetic activity and its cyclic evolutionary patterns.

Keywords: Solar cycle, Solar active regions, Solar activity, Solar magnetic fields
Polarization Characteristics of the Hyperactive FRB 20240114A. Fast radio bursts (FRBs) are transient radio bursts of extragalactic origin characterized by millisecond durations and high luminosities. We report on observations of FRB 20240114A conducted with the Robert C. Byrd Green Bank Telescope at frequencies ranging from 720 to 920 MHz. A total of 437 bursts were detected, with a single observation recording 365 bursts over 1.38 hr, corresponding to a burst rate of 264 bursts per hour. The average rotation measures (RMs) were 347.0 ± 1.0 rad m‑2 on 2024 February 23, and 353.7 ± 0.6 rad m‑2 on 2024 March 1. Of the 301 bursts with detected RMs, 81% have a linear polarization fraction greater than 90%, and 14% exhibit circular polarization with a signal-to-noise ratio &gt; 5. Our sample also displayed polarization angle swings. We compared the linear polarization fraction of FRB 20240114A with those of the repeating sources FRB 20201124A and FRB 20220912A. Our analysis reveals that all three exhibit similar distributions in both linear and circular polarization fractions. These results indicate that the three sources share the same radiation mechanism. We analyze the fluence and waiting-time distributions of FRB 20240114A, revealing a right-skewed fluence distribution and a bimodal waiting-time structure, suggesting intrinsic emission timescales and potential multiple burst populations. Additionally, we present a novel method to determine the frequency range of bursts based on their spectral characteristics. This algorithm is independent of spectral models and remains unaffected by the removal of interference-affected channels in the data, ensuring robust performance.

Keywords: Radio bursts, Radio sources, Radio transient sources
Performance-portable Numerical Relativity with AthenaK. We present the numerical relativity module within AthenaK, an open-source performance-portable astrophysics code designed for exascale computing applications. This module employs the Z4c formulation to solve the Einstein equations. We demonstrate its accuracy through a series of standard numerical relativity tests, including convergence of the gravitational waveform from binary black hole coalescence. Furthermore, we conduct scaling tests on OLCF Frontier, NERSC Perlmutter, and ALCF Aurora, where AthenaK exhibits excellent weak-scaling efficiency of 80% on up to 65,536 AMD MI250X GPUs on Frontier (relative to four GPUs) and 67% on Aurora up to 24,576 Intel Data Center Max Series GPUs (relative to 12 GPUs) and strong-scaling efficiencies of 84% and 77% on AMD MI250X and NVIDIA A100 GPUs on Frontier and Perlmutter, respectively. Additionally, we observe a significant performance boost, with 2 orders of magnitude speedup (≳200×) on a GPU compared to a single CPU core, affirming that AthenaK is well suited for exascale computing, and thereby expanding the potential for breakthroughs in numerical relativity research.

Keywords: Gravitational wave sources, Gravitational waves, Black holes, Compact objects
A Redshift Survey of the Coma Cluster (A1656): Understanding the Nature of Subhalos in the Weak-lensing Map. We study the physical properties of weak-lensing subhalos in the Coma cluster of galaxies using data from galaxy redshift surveys. The data include 12,989 galaxies with measured spectroscopic redshifts (2184 from our MMT/Hectospec observations and 10,807 from the literature). The r-band magnitude limit at which the differential spectroscopic completeness drops below 50% is 20.2 mag, which is spatially uniform in a region of 4.5 deg2 where the weak-lensing map of N. Okabe et al. exists. We identify 1337 member galaxies in this field and use them to understand the nature of 32 subhalos detected in a weak-lensing analysis. We use Gaussian mixture modeling (GMM) in the line-of-sight velocity domain to measure the mean velocity, the velocity dispersion, and the number of subhalo galaxies by mitigating contamination from interloping galaxies. Using subhalo properties calculated with the GMM, we find no significant difference in the redshift space distribution between the cluster member galaxies and subhalos. We find that the weak-lensing mass shows strong correlations with the number of subhalo member galaxies, velocity dispersion, and dynamical mass of subhalos with power-law slopes of  0.54‑0.15+0.16 ,  0.93‑0.32+0.35 , and  0.50‑0.18+0.31 , respectively. The slope of the mass–velocity dispersion relation of the weak-lensing subhalos appears shallower than that of galaxy clusters, galaxy groups, and individual galaxies. These results suggest that the combination of redshift surveys with weak-lensing maps can be a powerful tool for better understanding the nature of subhalos in clusters.

Keywords: Galaxy clusters, Weak gravitational lensing, Redshift surveys, Coma Cluster, Dark matter
Planet Masses, Radii, and Orbits from NASA's K2 Mission. We report the masses, sizes, and orbital properties of 86 planets orbiting 55 stars observed by NASA's K2 Mission with follow-up Doppler measurements by the HIRES spectrometer at the W. M. Keck Observatory and the Automated Planet Finder at Lick Observatory. Eighty-one of the planets were discovered from their transits in the K2 photometry, while five were found based on subsequent Doppler measurements of transiting planet-host stars. The sizes of the transiting planets range from Earth-size to larger than Jupiter (1–3 R⊕ is typical), while the orbital periods range from less than a day to a few months. For 32 of the planets, the Doppler signal was detected with significance greater than 5σ (51 were detected with &gt;3σ significance). An important characteristic of this catalog is the use of uniform analysis procedures to determine stellar and planetary properties. This includes the transit search and fitting procedures applied to the K2 photometry, the Doppler fitting techniques applied to the radial velocities (RVs), and the spectral modeling to determine bulk stellar parameters. Such a uniform treatment will make the catalog useful for statistical studies of the masses, densities, and system architectures of exoplanetary systems. This work also serves as a data release for all previously unpublished RVs and associated stellar activity indicators obtained by our team for these systems, along with derived stellar and planet parameters.

Keywords: Exoplanet astronomy, Radial velocity, Transit photometry, Exoplanet catalogs
FArSide Trained Active Region Recognition (FASTARR): A Machine Learning Approach. Helioseismic holography is a technique used to identify active regions in the Sun's far hemisphere by studying seismic disturbances in the Sun's visible hemisphere caused by acoustic waves in its interior that have reflected from its far hemisphere. Currently, identification of these active regions faces challenges due to limited signal-to-noise, resulting in reliable detection of only large and strong active regions. Based on well-developed machine learning networks, we present a convolutional far-side active region recognition algorithm that aims to enhance active region identification in far-side helioseismic maps. The algorithm is structured as a U-shaped convolutional neural network (U-Net) for accurate image segmentation and evaluation of the likelihood that a given helioseismic signature is indicative of a real active region. Our algorithm, known as FASTARR, is trained by pairing phase maps of the Sun's far hemisphere with concurrent far-side active region binary masks derived from phase maps and EUV observations of the far hemisphere. The helioseismic phase maps are computed using Dopplergrams observed by the National Solar Observatory/GONG. The active region masks are derived from two sources: EUV active region masks based on observations by the STEREO/EUVI, when it had a direct vantage covering the far hemisphere, and GONG active region masks derived from GONG helioseismic phase measurements. The model's validation demonstrates its efficacy for space weather forecasting during the ascending and maximum phases of solar cycle 24 (2010─2016). The results reveal that U-Net evaluation achieves greater sensitivity to active region presence in the Sun's far hemisphere compared to conventional methods.

Keywords: Solar extreme ultraviolet emission, Helioseismology, Space weather, Convolutional neural networks, Solar active regions, Solar oscillations
An Unsupervised Learning Method for Radio Interferometry Deconvolution. Given the incomplete sampling of spatial frequencies by radio interferometers, achieving precise restoration of astrophysical information remains challenging. To address this ill-posed problem, compressive sensing (CS) provides a robust framework for stable and unique recovery of sky brightness distributions in noisy environments, contingent upon satisfying specific conditions. We explore the applicability of CS theory and find that for radio interferometric telescopes, the conditions can be simplified to sparse representation. Building on this insight, we develop a deep dictionary (realized through a convolutional neural network), which is designed to be multiresolution and overcomplete, to achieve sparse representation and integrate it within the CS framework. The resulting method is a novel, fully interpretable unsupervised learning approach that combines the mathematical rigor of CS with the expressive power of deep neural networks, effectively bridging the gap between deep learning and classical dictionary methods. During the deconvolution process, the model image and the deep dictionary are updated alternatively. This approach enables efficient and accurate recovery of extended sources with complex morphologies from noisy measurements. Comparative analyses with state-of-the-art algorithms demonstrate the outstanding performance of our method, i.e., achieving a dynamic range nearly 45–100 times higher than that of multiscale CLEAN.

Keywords: Radio interferometry, Deconvolution, Astronomy image processing, Neural networks
Calibrating HMI Magnetograms Using an End-to-end Magnetograph Model. Numerous solar and space science and operations projects rely heavily on accurate, consistent magnetic field measurements from the solar surface. These projects are hindered by well-known but poorly understood discrepancies between magnetograms obtained with different solar telescopes and instrumentation. Existing efforts to characterize these discrepancies have mostly been limited to direct comparisons between final data products and have been inconclusive regarding the correct measurement. To attack this problem, we model every step of the line-of-sight (LOS) photospheric field measurement all the way to the final magnetogram. Beginning with known MHD simulation data for the magnetic field, the "ground truth," we compute for different viewing angles the radiative transfer for the Stokes spectra using the Rybicky and Hummer (RH) radiative transfer code. We then use the Solar Orbiter Polarimetric and Helioseismic Imager Software Simulator, adapted for the Solar Dynamics Observatory Helioseismic and Magnetic Imager (HMI) instrument, to simulate the instrument response to emergent polarized spectra. We model every significant process undergone by the solar signal during an observation: degradation by instrumental limitations including finite spatial and spectral resolution, Doppler shift variations due to the radial spacecraft orbital velocity, and the effects of Stokes inversion for the LOS magnetic field. Finally, we compare the simulated magnetograms with the MHD field data using the computed line formation information along each LOS and construct a detailed end-to-end magnetogram calibration. Effects of the calibration on real HMI magnetograms are discussed, including open magnetic flux estimates, and are compared with high-resolution data.

Keywords: Spectropolarimetry, The Sun, Astronomical instrumentation, Solar magnetic fields, Radiative transfer, Magnetogram
High-efficiency and Low-noise Detectors for the Upgraded CLASS 90 GHz Focal Plane. We present the in-lab and on-sky performance for the upgraded 90 GHz focal plane of the Cosmology Large Angular Scale Surveyor, which had four of its seven detector wafers updated during the austral winter of 2022. The update aimed to improve the transition-edge-sensor (TES) stability and bias range and to realize the high optical efficiency of the sensor design. Modifications included revised circuit terminations, electrical contact between the TES superconductor and the normal metal providing the bulk of the bolometer heat capacity, and additional filtering on the TES bias lines. The upgrade was successful: 94% of detectors are stable down to 15% of the normal resistance, providing a wide overlapping range of bias voltages for all TESs on a wafer. The median telescope efficiency improved from  0.42‑0.22+0.15  to  0.60‑0.32+0.10  (68% quantiles). For the four upgraded wafers alone, median telescope efficiency increased to  0.65‑0.06+0.06 . Given our efficiency estimate for the receiver optics, this telescope efficiency implies a detector efficiency exceeding 0.90. The overall noise-equivalent temperature of the 90 GHz focal plane improved from  19μKs  to  9.7μKs .

Keywords: Early universe, Cosmic microwave background radiation, Observational cosmology, CMBR detectors, Astronomical instrumentation, Polarimeters
The Milky Way as Seen by Classical Cepheids. I. Distances Based on Mid-infrared Photometry. Classical Cepheids are the archetype of the standard candle, thanks to the period–luminosity relation, which allows us to measure their intrinsic brightness. They are also relatively young and bright, potentially making them excellent tracers of the young stellar population that is responsible for shaping the visible aspect of our Galaxy. However, being observers embedded in the dusty interstellar medium of the Galaxy, deriving reliable photometric distances to classical Cepheids of the Milky Way is a challenge. The typical approach is to use "reddening-free" indices, such as Wesenheit magnitudes, to obviate the need for an extinction correction. However, this approach could lead to unknown systematics—especially toward the inner Galaxy—as its assumption of a universal total-to-selective extinction ratio is not satisfied, particularly in lines of sight where the extinction is high and crosses spiral arms. We instead estimate new distances for 3424 Cepheids based on mid-IR photometry from the Wide-field Infrared Survey Explorer, which suffers minimally from extinction, and by adopting a 3D extinction map to calculate the necessary (albeit small) extinction corrections. We show that our distances are consistent with Gaia's parallaxes for the subset with relative parallax errors smaller than 10%, verifying that our mean distance errors are of the order of 6% and that the mean parallax zero-point for this subsample is 7 μas.

Keywords: Galaxy structure, Standard candles, Distance indicators, Milky Way disk, Cepheid distance
The 2023 Flight of the Faint Intergalactic-medium Redshifted Emission Balloon. The second iteration of the Faint Intergalactic-medium Redshifted Emission Balloon (FIREBall-2) is a UV multiobject spectrograph designed to detect emission from the circumgalactic and circumquasar medium at low redshifts (z &lt; 1). The FIREBall-2 instrument uses a zero-pressure suborbital balloon to access a stratospheric transmission window centered around 205 nm. Following the payload's first flight in 2018, several refurbishments and modifications were made to the instrument and telescope to prepare for additional flight opportunities. Here we present an overview of upgrades and improvements made since the previous flight and discuss the 2023 field campaign, which culminated in a flight from Fort Sumner, New Mexico, in 2023 September. The flight was terminated early, prior to science observations; we report here the performance of the instrument in ground calibrations, the flight plan and timeline of events, and the in-flight guidance performance. We also discuss the limitations encountered in 2023 and the future outlook for FIREBall-2.

Keywords: Ultraviolet telescopes, Ultraviolet spectroscopy, Ultraviolet astronomy, High altitude balloons, Spectroscopy, Circumgalactic medium