Sazuna/UAT_keywords huggingface dataset:
Prospects for Measuring Black Hole Masses using TDEs with the Vera C. Rubin Observatory. Tidal Disruption Events (TDEs) provide an opportunity to study supermassive black holes that are otherwise quiescent. The Vera C. Rubin Legacy Survey of Space and Time will be capable of discovering thousands of TDEs each year, allowing for a dramatic increase in the number of discovered TDEs. The optical light curves from TDEs can be used to model the physical parameters of the black hole and disrupted star, but the sampling and photometric uncertainty of the real data will couple with model degeneracies to limit our ability to recover these parameters. In this work, we aim to model the impact of the Rubin survey strategy on simulated TDE light curves to quantify the typical errors in the recovered parameters. black hole masses  5.5&lt;logMBH/M⊙&lt;8.2  can be recovered with typical errors of 0.26 dex, with early coverage removing large outliers. Recovery of the mass of the disrupted star is difficult, limited by the degeneracy with the accretion efficiency. Only 57% of the cases have accurate recovery of whether the events are full or partial, so we caution the use this method to assess whether TDEs are partially or fully disrupted systems. black hole mass measurements obtained from Rubin observations of TDEs will provide powerful constraints on the black hole mass function, black hole─galaxy co-evolution, and the population of black hole spins, though continued work to understand the origin of TDE observables and how the TDE rate varies among galaxies will be necessarily to fully utilize the upcoming rich dataset from Rubin.

Keywords: Supermassive black holes, Tidal disruption
Mid-IR Luminosity Functions: Inferred Dusty Cosmic Star Formation and Black Hole Accretion Histories from the JWST SMILES. Mid-infrared (mid-IR) observations are crucial for understanding galaxy evolution, tracing star formation, and active galactic nuclei (AGN) activity via dust emission. This work presents mid-IR galaxy luminosity functions (LFs) at 0.5 &lt; z &lt; 6, derived from the JWST Systematic Mid-infrared Instrument Legacy Extragalactic Survey (SMILES) program. We combine 8 MIRI bands (5─25 μm) of SMILES and archival 23-band HST+JWST NIRCam photometry to construct an extensive catalog containing 2813 galaxies with sub-μJy level completeness in the mid-IR. We obtain monochromatic (in 5.6, 7.7, 10, 12.8, 15, 18, 21, and 25.5 μm), LIR, and AGN LFs, with a limiting luminosity down to 109.5 L⊙ at z = 0.5─1.0, ∼1010.5 L⊙ at z = 2.0─4.0, and to ∼1011 L⊙ at z = 4.0─6.0. With the unprecedented sensitivity and resolution of JWST, here we better constrain the faint-end slope and its evolution of the mid-IR LFs, quantifying the dusty cosmic star formation and black hole accretion histories out to z ∼ 5. These results provide essential insights to refine our understanding of the obscured star formation and galaxy-AGN co-evolution over cosmic time.

Keywords: Luminosity function, Active galaxies, Infrared galaxies, Galaxy evolution
Low-latency Forecasts of Kilonova Light Curves for Rubin and ZTF. The follow-up of gravitational-wave events by wide-field surveys is a crucial tool for the discovery of electromagnetic counterparts to gravitational wave sources, such as kilonovae. Machine learning tools can play an important role in aiding search efforts. We have developed a public tool to predict kilonova light curves using simulated low-latency alert data from the International Gravitational Wave Network during observing runs 4 (O4) and 5 (O5). It uses a bidirectional long-short-term memory model to forecast kilonova light curves from binary neutron star and neutron star─black hole mergers in the Zwicky Transient Facility (ZTF) and Rubin Observatory's Legacy Survey of Space and Time filters. The model achieves a test mean squared error (MSE) of 0.12 for ZTF filters and 0.23 for Rubin filters, calculated by averaging the squared error over all time steps, filters, and light curves in the test set. We evaluate the performance of the model against merger events followed-up by the ZTF partnership during O4c. We also analyze the effect of incorporating constraints on physical features such as ejecta mass. Using ejecta mass, the performance of the model improves to an MSE of 0.1 for ZTF filters and 0.15 for Rubin filters. Our model is publicly available and can help to add important information to help plan follow-up of candidate events discovered by current and next-generation public surveys.

Keywords: Gravitational waves, Neural networks
SHORES. II. Multi-frequency Characterization of the Sub-mJy Radio Population in FIR-selected Fields. We present a new deep multi-frequency radio survey of two extragalactic fields observed with the Australia Telescope Compact Array as part of the SHORES project (Serendipitous H-ATLAS-fields Observations of Radio Extragalactic Sources). The observations, centred at 2.1, 5.5, and 9 GHz, cover the central 0.5 deg2 of two Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) fields down to rms sensitivities of 9─17 μJy beam─1 at 2.1 GHz, 28─39 μJy beam─1 at 5.5 GHz and 38─61 μJy beam─1 at 9 GHz. This setup allows us to investigate the spectral energy distributions of faint radio sources and probe the nature of the sub-mJy population. We extract and validate a robust catalogue of 489 sources at 2.1 GHz, 101 of which are also detected at 5.5 GHz. We perform a multi-frequency analysis of the radio number counts and derive the spectral indices of sources in the deep fields. The spectral index distribution of our sources peaks around α ∼ −0.7, consistent with synchrotron emission from the faint radio population. The number counts at 2.1 GHz are consistent with previous deep surveys and theoretical models, and provide a lower limit on the star-forming galaxy (SFG) population, which is expected to dominate the faint end. The 5.5 GHz data offer new, direct constraints on the sub-mJy radio sky at higher frequencies. By cross-matching with the H-ATLAS catalogue, we identify a sample of sources with far-infrared (FIR) counterparts and explore the far-infrared-radio correlation. The sources with qFIR ≥ 1.69 exhibit radio spectral indices typical of SFGs. Furthermore, we identify a population of radio-only sources with similar indices that may correspond to high-redshift SFGs, lacking counterparts in the FIR survey due to its limited resolution and sensitivity.

Keywords: Starburst galaxies, Radio source catalogs, Far infrared astronomy, Radio galaxies, Radio source counts, Radio active galactic nuclei, Radio continuum emission, Radio astronomy, Radio sources
Classification of Double Neutron Stars Using the Extreme Deconvolution Method. The double neutron star (DNS) systems are pivotal compact binary systems for testing gravitational waves and general relativity—evidenced by radio telescope observations of their orbital decay and LIGO-Virgo-KAGRA detections of their coalescences. Thus, a systematic classification study of DNS systems can profoundly advance our understanding of their origins and evolutionary pathways. Based on a Gaussian mixture model, we applied the Extreme Deconvolution Method to the classification of an updated sample of 33 pairs of DNSs. Bayesian Information Criterion analysis reveals that these systems are best modeled by a three-Gaussian distribution in the orbital period─eccentricity plane, partitioning them into three distinct populations. Type I DNSs (5 systems): Characterized by low eccentricity and orbital periods shorter than 1 day, they are likely to merge within the Hubble time. Type II DNSs (13 systems): Exhibiting significantly diversified parameter distributions, these systems show longer orbital periods and higher eccentricities compared to Type I. Type III DNSs (14 systems): These systems exhibit much longer orbital periods and various eccentricities. DNS orbital period─eccentricity correlations infer distinct formation channels: Type I systems are likely associated with ultra-stripped supernovae, and Type II systems may arise from electron capture supernovae, while Type III systems likely originate from iron-core collapse supernovae. We conclude that three unconventional DNSs (PSR J0509+3801, B1534+12, and J1757-1854) in which the non-recycled NSs are heavier than the recycled pulsars should belong to Type II DNSs. The non-recycled NSs in these systems possibly formed through electron capture supernovae.

Keywords: Neutron stars, Astronomy data analysis, Pulsars
Four Giant Planets from 2024 KMTNet Microlensing Campaign. In this work, we present analyses of four newly discovered planetary microlensing events from the 2024 KMTNet survey season: KMT-2024-BLG-0176, KMT-2024-BLG-0349, KMT-2024-BLG-1870, and KMT-2024-BLG-2087. In each case, the planetary nature was revealed through distinct types of anomalies in the lensing light curves: a positive bump near the peak for KMT-2024-BLG-0176, an asymmetric peak for KMT-2024-BLG-0349, a short-duration central dip for KMT-2024-BLG-1870, and a caustic-crossing feature for KMT-2024-BLG-2087. Detailed modeling of the light curves confirms that these anomalies are produced by planetary companions with planet-to-host mass ratios in the range of (1.5−17.9) × 10−3. Despite the diversity of signal morphologies, all planets detected in these events are giant planets with masses comparable to or exceeding that of Jupiter in the solar system. Each planet orbits a host star less massive than the Sun, emphasizing the strength of microlensing in uncovering planetary systems around low-mass stellar hosts.

Keywords: Gravitational microlensing exoplanet detection
Degassing of Comet Analogs: New Laboratory Measurements of Vapor Pressure between Sand─Ice Agglomerates. This work aims to investigate the rate of production of vapor from the nuclei of comets when they are composed of porous dust─ice agglomerates of different sizes. The reason for starting the research was the discrepancy between the values of vapor pressure between agglomerates required by different theoretical models to reproduce the results of experiments. The model of sublimation of ice from dust─ice agglomerates used in Fulle et al. and Ciarniello et al. assumes zero pressure between agglomerates. However, the generalized model with the pressure between agglomerates being a function of temperature reproduces the results of laboratory experiments when the vapor pressure should not be close to zero. In the present work, we present new experiments including direct measurements of the gas pressure within samples composed of porous agglomerates. The measured pressure is clearly higher than zero. The results of the experiments are compared with the results of mathematical simulations.

Keywords: Comet nuclei, Comet surfaces
Rapid Brightening of 3I/ATLAS Ahead of Perihelion. Interstellar comet 3I/ATLAS has been approaching its 2025 October 29 perihelion while opposite the Sun from Earth, hindering ground-based optical observations over the preceding month. However, this geometry placed the comet within the fields of view of several space-based solar coronagraphs and heliospheric imagers, enabling its continued observation during its final approach toward perihelion. We report photometry from STEREO-A's SECCHI HI1 and COR2, SOHO's LASCO C3, and GOES-19's CCOR-1 instruments in 2025 September─October, which show a rapid rise in the comet's brightness scaling with heliocentric distance r as r−7.5±1.0. CCOR-1 also resolves the comet as an extended source with an apparent coma of  ∼4'  in diameter. Furthermore, LASCO/CCOR-1 color photometry shows the comet to be distinctly bluer than the Sun, consistent with gas emission contributing a substantial fraction of the visible brightness near perihelion.

Keywords: Broad band photometry, Comets, Coronagraphic imaging
A Simple, Flexible Method for Timing Cross-calibration of Space Missions. The timing (cross-)calibration of astronomical instruments is often done by comparing pulsar times-of-arrival (TOAs) to a reference timing model. In high-energy astronomy, the choice of solar system ephemerides and source positions used to barycenter the photon arrival times has a significant impact on the procedure, requiring a full reprocessing of the data each time a new convention is used. Our method, developed as part of the activities of the International Astronomical Consortium for High Energy Calibration, adapts an existing pulsar solution to arbitrary JPL ephemerides and source positions by simulating geocentric TOAs and refitting timing models (implemented with PINT). We validate the procedure and apply it to thousands of observations of the Crab pulsar from 15 missions spanning 1996─2025, demonstrating inter-ephemeris TOA consistency at the ≲5 μs level, using the DE200/FK5-based Jodrell Bank Monthly Ephemeris as a common reference. We release the TOAExtractor open-source tool and a TOA database to support future calibration and scientific studies. Instrument timing performance is broadly consistent with mission specifications; the X-ray-to-radio phase offset varies with energy and time at a level that is marginally consistent with the uncertainties of the radio ephemeris, motivating coordinated multiwavelength follow-up.

Keywords: Calibration, Cross-validation , Pulsar timing method, Time series analysis
SENPAI: Sidereal Enriched Rate-track Astrometry in Deep Imagery of Solar System Bodies. Rate-track imagery−in which a telescope tracks an object's proper motion instead of the stellar background−has long been used to enhance the signal-to-noise ratio of faint solar system bodies such as asteroids, comets, and artificial satellites. Images from such observations are characterized by point source targets and streaked stars. While astrometric plate solving−matching ubiquitous and unique star fields to a world coordinate system−is a mature field of research, the complexities of detecting and measuring the centroid of star streaks in rate track imagery decreases astrometric accuracy. This is unfortunate, given that defining and refining orbits of bodies of the solar system require accurate astrometric positions. In this work, we propose a novel observing methodology for experiments requiring the enhanced signal-to-noise ratio of rate track imagery and the astrometrics of orbiting solar system bodies by capping rate track sequences with a sidereal observation at the tracked object's position. The resulting data provide high-precision astrometry and a natural filter for detecting star streaks in the rate-track imagery. We demonstrate astrometric uncertainties in right ascension and declination of ≤1 .″ 38 and ≤0 .″ 96, respectively, on observations of calibration satellites using telescopes with pixel scales (instantaneous field's of view) of 0 .″ 90─1 .″ 68. This technique−Sidereal ENriched Precision Astrometric Intelligence (SENPAI)—is designed to run automatically, requires no tuning or calibration frames on a per sensor basis, and throughput exceeds 85% on most sensors tested. SENPAI far exceeds the threshold requirement of ≤3 .″ 0 of uncertainty in object positioning for initial determination of—and state updates to—the orbits of artificial satellites.

Keywords: Detection, Surveys, Artificial satellites, Automated telescopes, Algorithms
Astrophysical or Terrestrial: Machine Learning Classification of Gravitational-wave Candidates Using Multiple-search Information. Low-latency gravitational-wave alerts provide the greater multi-messenger community with information about the candidate events detected by the International Gravitational-Wave Network. Prompt release of data products such as the sky localization, false alarm rate, and pastro values allow astronomers to make informed decisions on which candidate gravitational-wave events merit target of opportunity follow-up. However, false alarms where a gravitational-wave candidate, or trigger, is the result of terrestrial noise, are an inherent part of gravitational-wave searches. In addition, with the presence of multiple gravitational-wave searches, different searches may have varying assessments of the significance of a given trigger. As a complement to quantities such as pastro, we provide a Machine Learning (ML) based approach to determining whether candidate events are astrophysical or terrestrial in nature. This ML classifier utilizes information provided by multiple low-latency search pipelines and downstream data products in its feature space, and is trained on a realistic real-time simulation campaign called the Mock Data Challenge (MDC). The Random Forest implementation has an Area Under the Receiver Operating Characteristic Curve (AUC) of 0.96 and accuracy of 0.90 on the MDC training set compared to pastro which had an AUC of 0.72 and an accuracy of 0.75. We tested on events from Advanced LIGO (aLIGO)'s, Advanced Virgo (AdVirgo)'s, and KAmioka GRAvitational-wave observatory (KAGRA)'s third observing run (O3) and got an AUC of 0.93 and accuracy of 0.86 compared to pastro which had an AUC of 0.82 and accuracy of 0.75.

Keywords: Gravitational wave astronomy, Gravitational waves
Design of a New Solar Radio Observing System Working in 3─6 GHz. Solar radio bursts from decimeter to centimeter wavelength originate from radiations from coherent to incoherent mechanism. This spectral domain hosts a rich variety of fine structures that encode critical information about energetic electron beams, coronal magnetic fields, and ambient plasma conditions—key elements for understanding particle acceleration and energy release during solar flares. To exploit this diagnostic potential, a broadband observing system with high time and frequency resolution is essential. In this study, we designed and developed the Chashan Broadband Solar Decimetric Spectrometer (CBSdm), which enables high-precision observation of solar radio bursts in the 3─6 GHz frequency band. The system employs a 6 m parabolic antenna with a log-periodic dipole array feed, and utilizes nanosecond-level microwave switching technology to construct a dual-channel analog receiving chain (3.1─4.4 GHz/4.6─5.9 GHz). Real-time spectral processing is achieved via a 14-bit 3 GSPS analog-to-digital converter and an Field Programmable Gate Array-based digital backend. Key performance metrics include a noise figure of 2 dB, sensitivity of −77.9 dBm@2.6 GHz, and system linearity better than 0.998. Relative calibration was performed and cross-validated with data from the Learmonth Observatory. Since its deployment in 2023 October, the system has successfully captured X-class flare events, with dynamic spectra exhibiting typical continuum features and multi-frequency synchronous evolution. The coordinated observations of CBSdm (3─6 GHz) and CBScm (6─15 GHz) provide continuous gyrosynchrotron spectra covering the optically thick to thin transition, enabling diagnostics of flare magnetic fields and nonthermal electron distributions.

Keywords: Solar radio telescopes, Solar flares, Astronomical instrumentation, Spectroscopy
MSIHP-Net: A Multiscale Deep Learning Method for Identifying Green Pea Galaxies. Green Pea galaxies (GPs) are a rare class of compact, low metallicity star-forming galaxies characterized by strong [O III] λ5007 emission lines, and high specific star formation rates in surveys such as Sloan Digital Sky Survey (SDSS) and Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). However, traditional manual or semi-automated approaches to identifying GPs face significant challenges in processing large-scale spectroscopic datasets from SDSS and LAMOST due to data volume and spectral complexity, and lack of efficient automated methods tailored for spectra hinders comprehensive GP studies. To address these issues, we propose a lightweight deep learning model with a small parameter count, termed Multiscale Inception Hybrid Pooling Network (MSIHP-Net) for automated and efficient GP identification. To rigorously evaluate the model's performance, we construct different datasets sourced from SDSS and LAMOST, incorporating various signal-to-noise ratios (SNRs). The MSIHP-Net architecture is built upon a sequence of three consecutive InceptionBlock1D modules. Each module employs parallel convolutions with varying kernel sizes to perform multiscale feature extraction across different receptive fields. This is followed by a hybrid pooling layer that concatenates the outputs of adaptive average pooling and adaptive max pooling, thereby preserving both local and global information. Experimental results demonstrate that MSIHP-Net consistently achieves the highest accuracy, F1-score, precision, and recall for the GP category in all datasets with varying SNRs. Extensive experiments indicate the superior performance and robustness of MSIHP-Net. These advances offer a promising approach to further exploring the characteristics and evolutionary behaviors of GPs.

Keywords: Classification, Emission line galaxies, Astronomy data analysis, Galaxies
KDP as A Thermal Blocking Filter—Deep Near IR Observations with A Warm Narrow Band Filter. Ground-based astronomy suffers from strong atmospheric line- and thermal continuum emission, at the near-infrared (NIR, 0.7─1.1 μm), and short-wave infrared (SWIR, 1.1─2.5 μm) wavelengths. The thermal continuum emission increases exponentially towards the red sensitivity cutoff of the state-of-the-art 2.5 μm cutoff SWIR detectors. Given availability of an optical quality shortpass filter material with strong blocking density in the SWIR, lower cost instrumentation, and higher performance filters could be designed. We demonstrate monopotassium dihydrogen phosphate (KDP, chemical formula KH2PO4) as a strong candidate for this purpose. KDP is fully transparent at wavelengths from ultraviolet to 1.3 μm, but becomes highly opaque at wavelengths &gt;2 μm. We demonstrate on-sky use of KDP by improving performance of a cryogenic broadband filter with known off-band thermal leak, and using a non-cryogenic narrow band filter for deep observation. KDP reduces the sky background by 4.5 mag in the leaky Z-band filter we use. Our 4 nm wide, central wavelength 1.191 μm narrowband filter in combination with KDP reduces the sky surface brightness by three magnitudes compared to a J broadband, although the effect of KDP is minor due to high blocking density of the broaband filter. We find a sky surface brightness of 18.5 mag arcsec−2 in our bandpass at 1.191 μm. KDP is an excellent thermal blocker, when its temperature is maintained above its Curie point at 123 K. Below Curie point, KDP transforms its crystal structure, degrading its otherwise good imaging properties.

Keywords: Diffuse radiation, Astronomical instrumentation, Astronomical optics, Near infrared astronomy