Sazuna/UAT_keywords huggingface dataset:
Gnuastro: Measuring Radial Profiles from Images. Radial profiles play a crucial role in the analysis and interpretation of astronomical data, facilitating the extraction of spatial information. However, highly customizable (for different scenarios) measurements over each elliptical annulus can be challenging. In response, we present astscript-radial-profile, which is part of Gnuastro from version 0.15 and has an extensive documentation. A convenient feature of this program is its capability to make the measurements with different operators (mean, median, sigma-clipping, and many more) over ellipses, very quickly and directly on the command-line with minimal dependencies. This research note is reproducible with Maneage, on the Git commit f3ec942.

Keywords: Open source software, Astronomy software, Astronomical techniques, Broad band photometry, Astronomy data visualization
Seventeen 2 Micron All Sky Survey (2MASS) Hypervelocity Stars (HVS) from Gaia DR3. As part of an ongoing search for hypervelocity stars I found seventeen two micron all sky survey sources with Gaia G magnitudes less than 16.0 and radial velocities less than -600 km s-1. All these stars are brighter in the K band when compared with their V and G magnitudes. Ten of these (including three carbon stars) are long period variable stars of Mira type. One is a relatively nearby high proper motion star and one is a very high galactic latitude chemically peculiar metal-poor star. It may be a galactic halo star. One star is a Kepler red giant, two stars may be cluster members and two are in the star-forming region (probably YSOs). It is not clear how these stars acquired such high radial velocities. Further study of these seventeen stars is needed.

Keywords: Hypervelocity stars
A Bigger Cloud 9? New H I Observations of the RELHIC Candidate M94- Cloud 9. We present new H I observations of the REionization-Limited H I Cloud (RELHIC) candidate, M94-CL9, detected around M94 by Zhou et al. using the Five-hundred-meter Aperture Spherical Telescope (FAST). M94-CL9's H I properties as detected by FAST are consistent with a RELHIC as noted by Benitez-Llambay &amp; Navarro. Our observations with the Robert C. Byrd Green Bank Telescope detect greater H I emission in M94-CL9 and result in H I properties that are larger (corrected velocity width, W 50,c,t  = 35.7 ± 0.6 km s-1; and integrated flux, ∫Sdv = 0.28 ± 0.04 Jy km s-1) than those found by Zhou et al. but that match those from the FAST All-Sky H I survey. These larger properties do not preclude M94-CL9 from being a RELHIC, but the wider spectral extent and spectral asymmetry reported here may be in tension with predictions of RELHIC properties.

Keywords: Dwarf galaxies, Neutral hydrogen clouds
Controlling Randomization in Astronomy Simulations. As the primary requirement, correctly implementing and controlling random number generation is vital for a range of scientific analyses and simulations across astronomy and planetary science. Beyond advice on how to set the seed, there is little guidance in the literature for how best to handle pseudo-random number generation in the current era of open-source astronomical software development. We present our methodology for implementing a pseudo-random number generation in astronomy simulations and software and share the short lines of python code that create the generator. Without sacrificing randomization at run time, our strategy ensures reproducibility on a per function/module basis for unit testing and for run time debugging where there may be multiple functions requiring lists of randomly generated values that occur before a specific function is executed.

Keywords: Open source software
Ultraviolet and Blue Optical Imaging of UVCANDELS. The UltraViolet Imaging of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey Fields (UVCANDELS) survey provided ultraviolet F275W imaging with coordinated parallel optical F435W imaging in four of the five CANDELS fields: GOODS-N, GOODS-S, EGS, and COSMOS, covering a total area of ~426 arcmin2. UVCANDELS takes primary WFC3/UVIS F275W exposures at a uniform 3-orbit depth and ACS F435W exposures (in parallel) at slightly varying depth due to the roll angle constraints and the overlap from the increased field of view of the ACS camera, reaching a limiting magnitude of ~27 and ~28 ABmag (5σ in 0.″2 apertures) for F275W and F435W, respectively. We present the results of the UVCANDELS observations, custom calibrations, and the creation of F275W and F435W imaging mosaics, which have been made publicly available on the Barbara A. Mikulski Archive for Space Telescopes.

Keywords: Astronomical techniques, Galaxy photometry, High-redshift galaxies, Galaxy evolution
The Gravitational Wave AfterglowPy Analysis (GWAPA) webtool. We present the first release of the Gravitational Wave AfterglowPy Analysis (GWAPA) webtool (Available at https://gwapa.web.roma2.infn.it/). GWAPA is designed to provide the community with an interactive tool for rapid analysis of gravitational wave afterglow counterparts and can be extended to the general case of gamma-ray burst afterglows seen at different angles. It is based on the afterglowpy package and allows users to upload observational data and vary afterglow parameters to infer the properties of the explosion. Multiple jet structures, including top hat, Gaussian and power laws, in addition to a spherical outflow model are implemented. A Python script for MCMC fitting is also available to download, with initial guesses taken from GWAPA.

Keywords: Gamma-ray bursts, Astronomy data modeling, Astronomy data analysis
Discovered the Long-term Variation of the Variable Star CzeV818. In this study we describe the reclassification of the variable star CzeV818, discovered in 2015 by Pavel Cagas (Skarka et al. 2017), which was cataloged as a delta Scuti variable. From the photometric study performed with the telescopes of the SSV-UAI-GRAV (Unione Astrofili Italiani, Variable Star Section), All-Sky Automated Survey for Supernovae (Kochanek et al. 2017) (ASAS-SN) and Zwicky Transient Facility (Masci et al. 2019) (ZTF) surveys and the G-spectrum obtained from Gaia DR3 (Gaia Collaboration et al. 2023) (Astrophysical parameters inference system, Apsis) data, it was possible to understand that the luminous variation was not due to pulsations but due to spots (as discussed in Roxburgh 1964), present in the photosphere with a cycle of 0.402533 day (9.66 hr). Analyzing the long-term data present in the ASAS-SN and ZTF surveys, it was possible to determine a cycle of 2900 days (7.95 yr), which is similar to the solar cycle.

Keywords: Starspots, Variable stars
A Size Estimate for Galaxy GN-z11. GN-z11 is the highest redshift galaxy spectroscopically confirmed with the Hubble Space Telescope (HST). Previous measurements of the effective radius of GN-z11 utilized GALFIT, which is not optimized to measure structural parameters for such a faint, distant object. Using new software called FORCEPHO, we derive a size from images in the F160W band obtained both from the complete CANDELS survey and additional midcycle observations in order to contribute to the knowledge base on the size evolution, size–luminosity, and size–mass relation of early galaxies. We find a half-light radius mean of 0.″036 ± 0.″006 corresponding to a physical size of 0.15 ± 0.025 kpc. This size, smaller than the point-spread function, is dramatically smaller than previous estimates with shallower HST data using galfit but consistent with recent measurements using forcepho on new JWST data. Such a small size suggests that GN-z11's high luminosity is dominated by an active galactic nucleus.

Keywords: AGN host galaxies, Active galactic nuclei, Galaxy evolution
A Note on the Flattop Velocity Distribution in Space Plasmas. A flattop velocity distribution is one of the most characteristic distributions in space plasmas. I discuss its properties using the generalized beta-prime distribution. Then I present a sampling algorithm for generating the flattop distribution in particle-in-cell and Monte Carlo simulations.

Keywords: Monte Carlo methods, Computational methods, Algorithms, Plasma physics
Is the Far-ultraviolet Flux of 21 Com Anticorrelated to its Optical Brightness?. The comparison of 20 ultraviolet spectra of 21 Com taken over continuous 24 hr to the optical counts collected by the Fine Error Sensor on board IUE reveals that large variations observed shortwards of 1700 Å occur in anti-phase with the optical brightness for part of the observations but not all. In this data, the FUV flux at 1540 Å reaches a minimum at rotational phase 0.32 and increases afterwards while the FES counts continue to increase after this phase. The Fe II resonance line at 1608.45 Å is Doppler shifted by 0.13 Å at phase 0.00 and ‑0.13 Å at phase of FUV flux minimum.

Keywords: Chemically peculiar stars
A Possible Orbital Period of MAXI J0158-744. Optical Gravitational Lensing Experiment (OGLE) has observed Monitor of All-sky X-ray Image J0158-744 for at least 10 yr since the X-ray/optical burst in 2011, which is a Be+ White Dwarf Supersoft source. By analyzing the OGLE light curve, we noticed that the optical brightness was changing periodically, indicating a possible orbital period of ${439}_{-80}^{+114}$ days.

Keywords: White dwarf stars, Periodic orbit
shock_cooling_curve: A Python-based Package for Extensive and Efficient Modeling of Shock Cooling Emission in Supernovae. The light-curve evolution of a supernova contains information on the exploding star. Early-time photometry of a variety of explosive transients, including Calcium-rich transients and type IIb/Ibc and IIP supernovae shows evidence for an early light curve peak as a result of the explosion's shock wave passing through extended material (i.e., shock cooling emission (SCE)). Analytic modeling of the SCE allows us to estimate progenitor properties such as the radius and mass of extended material (e.g., the stellar envelope) as well as the shock velocity. In this work, we present a Python-based open-source code that implements four analytic models originally developed in Piro, Piro et al. and Sapir &amp; Waxman applied to photometric data to obtain progenitor parameter properties via different modeling techniques (including nonlinear optimization, Markov Chain Monte Carlo sampling). Our software is easily extendable to other analytic models for SCE and different methods of parameter estimation.

Keywords: Shocks, Open source software, Supernovae
Non-detection of Radio Pulsations in the High-mass X-Ray Binary V0332+53 During Quiescence. Following recent discoveries of ultra-long-period radio-loud neutron stars located beyond death line models in the pulsar period-period derivative diagram, we performed a radio pulsation search in the high-mass X-ray binary V0332+53 during quiescence. Although the period and magnetic field of the neutron star in this binary make it the most promising high-mass X-ray binary to explore for this purpose, the GBT observations do not reveal radio pulsations. Here, We present the duty-cycle-dependent flux density limits on the presence of any pulsations and briefly discuss its possible origins: the intrinsic absence or faintness of pulsations, the presence of low-level residual accretion, or eclipses and/or pulse scattering due to the presence of a massive binary companion.

Keywords: Radio astronomy, High mass x-ray binary stars, Radio pulsars, Pulsars
Virial Velocities for Stellar Flybys with Planetary Disks in Star Formation Regions. In this work, we show the effect of different velocities of stellar encounters with planetary disks to support the use of virial or constant velocities in simulations of typical star-forming clusters; the variety of observed member velocity values in such objects can cause concern when selecting velocities for simulations. In this work, we employ different velocities from 1.5 to 10 km s‑1 with constant flyby masses, approach distances, and impact angles for encounters with a disk. We found that these velocities produce similar results, which suggests that such simulations can use virial or constant velocities without loss of accuracy.

Keywords: Orbits, Debris disks, Protoplanetary disks, Stellar dynamics
Dynamical Classifications of Multi-opposition TNOs as of 2023 December. We report the dynamical classifications of 3357 observed outer solar system objects listed as transneptunian objects (TNOs) or Centaurs by the Minor Planet Center. We use the Gladman et al. classification scheme to identify 28 Jupiter-coupled objects (all secure), 168 Centaurs (all secure), 234 scattering TNOs (70 secure/164 insecure), 204 detached TNOs (118 secure/86 insecure), 1650 classical TNOs (1494 secure/156 insecure), and 1073 resonant TNOs (907 secure, 166 insecure). Among the resonant TNOs, the most observationally populated resonance is the close-in 3:2 MMR with 452 objects, followed by the 2:1 with 105 objects, the 7:4 with 103 objects, the 5:3 with 68 objects, and the 5:2 with 56 objects. We discuss a few notable objects here, but all classifications and plots of the 10 Myr integrations are available in a linked GitHub repository.

Keywords: Kuiper belt, Classical Kuiper belt objects, Resonant Kuiper belt objects, Detached objects, Trans-Neptunian objects
A Radio Technosignature Search of Six Resonant Sub-Neptunes Orbiting HD 110067. We describe archival observations and analysis of the HD 110067 planetary system using the Green Bank Telescope (GBT) as part of the Breakthrough Listen search for technosignatures. The star hosts six sub-Neptune planets in resonant orbits, and we tune the drift rate range of our search to match the properties of the system derived by Luque et al. Our observations cover frequencies from 1 to 11.2 GHz, using the GBT's L, S, C, and X-band receivers, to an equivalent isotropic radiated power limit of ∼3 × 1012 W. No technosignatures were found, but this unusual system remains an interesting target for future technosignature searches.

Keywords: Search for extraterrestrial intelligence, Technosignatures, Radio astronomy, Exoplanets
Thirty Bright High Velocity B, A, and F Stars that may have Late-type Companions. I found thirty high velocity stars that have large V ‑ K values compared to standard stars of similar spectral types indicating the possible presence of late-type companion stars. All these thirty stars are relatively bright nearby stars with accurate Gaia DR3 parallaxes and radial velocities. There is hardly any relevant literature on these stars. There are 18 high galactic latitude stars in this sample. In order to further understand their chemical composition, evolutionary status, binary companions and how these stars acquired high radial velocities high resolution spectroscopy, radial velocity and photometric monitoring studies are very much needed.

Keywords: High-velocity stars
Recovery and Classification of Spherules from the Pacific Ocean Site of the CNEOS 2014 January 8 (IM1) Bolide. We have conducted an extensive towed-magnetic-sled survey during the period 2023 June 14–28, over the seafloor about 85 km north of Manus Island, Papua New Guinea, centered around the calculated path of the bolide CNEOS 2014 January 8 (IM1). We found about 850 spherules of diameter 0.05–1.3 mm in our samples. They were analyzed by microXRF, Electron Probe Microanalyzer and ICP Mass spectrometry. We identified 22% of the spherules as the product of planetary igneous differentiation and labeled them as D-type spherules. A small portion of the D-spherules show an excess of Be, La and U, by up to three orders of magnitude relative to the solar system standard of CI chondrites, and a composition pattern that is distinctly different from coal fly ash.

Keywords: Meteors
Flares from Space Debris in LSST Images. Owing to the exceptional sensitivity of the Vera C. Rubin Observatory, we predict that its upcoming LSST images will be contaminated by numerous flares from centimeter-scale space debris in Low Earth Orbits (LEO). Millisecond-duration flares from these LEO objects are expected to produce detectable image streaks of a few arcseconds with AB magnitudes brighter than 14.

Keywords: Sky surveys
Faint Comet Detection with Unistellar eVscopes. We present eVscope observations of comets 12P/Pons-Brooks and C/2023 A3 (Tsuchinshan-ATLAS) when their magnitudes were greater than 16th magnitude. From a set of two observations of 12P taken on 2023 June 19 and 20, we measure an apparent magnitude of G = 16.59 ± 0.31. From four sets of observations of C/2023 A3 taken on 2023 April 14, 25, 26, and May 9, we measure apparent magnitudes of G = 16.78 ± 0.41, 16.55 ± 0.29, 16.71 ± 0.28, 16.59 ± 0.18 respectively. These images were taken from Unistellar telescope models: eVscope 1 and 2. We find an average background value of G = 17.35 ± 0.21.

Keywords: Automated telescopes, Comets, Ground telescopes, Telescopes
Hidden Companions to Intermediate-mass Stars. XV. Discovery of a 1.2M <SUB>⊙</SUB>, 8.4 au Companion to the δ Scuti star HIP 41375 = 2 Hydrae. 2 Hydrae is a nearby M Aa = 1.66M ⊙ δ Scuti star with strong astrometric evidence for a close companion in addition to its known M  B  = 0.20M ⊙ M dwarf companion at 530 au. Here we report on a VLTI/GRAVITY near-infrared interferometric observation that reveals the close companion to be a M Ab = 1.18M ⊙ star at a projected separation ρ = 168 mas ↔ 8.4 au. This triple system is a potential progenitor for a double white dwarf binary under the dynamical influence of an outer M dwarf companion with a low enough hierarchy for potentially interesting dynamical effects. *Based on observations collected at the European Southern Observatory, Chile, Program ID 110.241W.001.

Keywords: Optical interferometry, Multiple stars, Delta Scuti variable stars, A stars
Comparison of Convolutional Neural Networks and Random Forest Classifiers for Strong Gravitational Lens Identification. Strong gravitational lenses have been instrumental in providing insight into various astronomical problems, including analyzing the dark matter distribution of the universe. Effective identification of these events is made possible through machine learning algorithms, with many recent studies focusing on neural networks. However, very few have investigated the tradeoffs between different algorithms besides neural networks for lens identification. Our paper compares a convolutional neural network (CNN) and a random forest classifier (RFC) to determine the benefits of each for this task. We find that while CNNs do achieve higher accuracy, using RFCs to supplement them could increase the effectiveness of such algorithms. As a result, models that utilize both side-by-side to make predictions may increase in accuracy. This should be explored by future research.

Keywords: Optical identification, Strong gravitational lensing
Radio Properties of the Quasar J1718+4239, the Proposed Source of the Neutrino Event IceCube-201221A. NVSS J171822+423948 was recently identified as the most probable counterpart of the neutrino event IC-201221A. Based on the highly variable γ-ray, optical, and mid-infrared emission, the dates of the flaring events, and optical spectroscopy in the field of interest, this object was classified as a neutrino-emitting blazar candidate. Since its radio properties were not discussed in detail, we present archival observations. High-amplitude total radio flux density variability supports the connection between the flares at higher energies and the neutrino event.

Keywords: Radio loud quasars, Blazars, Gamma-ray sources, Cosmological neutrinos
An Enigmatic High Excitation Nebula in IC 1613 Dwarf Galaxy. We report the serendipitous discovery of a high-excitation nebula in the Local Group dwarf galaxy IC 1613. The nebula shows spectral features typical of a planetary nebula (PN), but its physical size makes it an order of magnitude larger than observed for this type of object, if indeed it belongs to IC 1613. We hypothesise that it may be an example of an over-luminous PN, a still unexplained phenomenon that deserves further investigation.

Keywords: Dwarf irregular galaxies, Spectroscopy
The Application of Machine Learning to Quasar and Seyfert Classification. Machine learning can be utilized to classify spectra flagged as Active Galactic Nuclei (AGNs) belonging to Seyferts or Quasars, expediting data collection and aiding in analyzing the AGN types. While many properties of Seyferts and Quasars can be used as feature points in training a machine learning model, one relatively available property with high information density is the spectra of the AGN types. This paper aims to describe the training and results of a K-Nearest Neighbors and a Dense Neural Network machine learning model built to classify AGNs as Seyfert type 1s, Seyfert type 2s, or Quasars.

Keywords: Neural networks, Quasars, Active galaxies, Galaxy classification systems, Seyfert galaxies, Active galactic nuclei
Reevaluating LSST's Capability for Time Delay Measurements in Quasar Accretion Disks. The Legacy Survey of Space and Time at the Vera C. Rubin Observatory is poised to observe thousands of quasars using the Deep Drilling Fields (DDF) across six broadband filters over a decade. Understanding quasar accretion disk (AD) time delays is pivotal for probing the physics of these distant objects. Pozo Nuñez et al. has recently demonstrated the feasibility of recovering AD time delays with accuracies ranging from 5% to 20%, depending on the quasar's redshift and time sampling intervals. Here we reassess the potential for measuring AD time delays under the current DDF observing cadence, which is placeholder until a final cadence is decided. We find that contrary to prior expectations, achieving reliable AD time delay measurements for quasars is significantly more challenging, if not unfeasible, due to the limitations imposed by the current observational strategies.

Keywords: Extragalactic astronomy, Astrophysical black holes, Quasars
extrabol: A Python Package for Estimating Bolometric Light Curves of Thermal Transients. We introduce a new, open-source, Python-based package, extrabol, for inferring the bolometric light curve evolution of extragalactic thermal transients. extrabol uses non-parametric Gaussian Process regression for light curve estimation that requires minimal user interaction. extrabol is available via GitHub.

Keywords: Light curves, Time domain astronomy, Gaussian Processes regression
Quantifying Solar Radiation Pressure Effects on Dust at Small Heliocentric Distances. The dynamics of dust grains has traditionally been modeled under the assumption that the ratio of the opposing solar radiation pressure and gravitational forces is fixed for an individual, unchanging grain. However, at small heliocentric distances, this assumption is inaccurate, as the variation in radiation pressure force with heliocentric distance does not follow an inverse square law there, as the Sun cannot be approximated as a point source of light. To correct for this, we have calculated the required correction to assumed radiation pressure force values, taking into account the decrease in both the visible solar area and in the radial solar radiation force components. We present here an empirical fit to this correction, for heliocentric distances 0.028–1.00 au. This correction may be used to more accurately simulate dust motion near the Sun.

Keywords: Near-sun comets, Solar system, Solar F corona, Comet dust tails, Zodiacal cloud, Comets