Sazuna/UAT_keywords huggingface dataset:
Investigating the Accuracy of Virial Cluster Masses: King Model Simulations. Stars form in clusters within giant molecular clouds. Spectroscopic observations can reveal radial velocities from which virial masses can be estimated. The question we are investigating is how accurate these estimates are with respect to the number of stars observed. We simulated virialized clusters with King model distributions and from these clusters we simulated mock observations. From these observations cluster sizes and virial masses are estimated, and empirical distribution functions are constructed. A confidence interval table is produced considering the number of objects observed and the ratio of velocity dispersion to observational uncertainty.

Keywords: Star formation, Radial velocity, Young star clusters, Confidence interval
Updated Ephemeris and Evidence for a Period Change in the Eclipsing Novalike Variable 1RXS J064434.5+334451. We report seven new eclipse timings for the novalike variable 1RXS J064434.5+334451. An analysis of our data, along with all previously available timings (36 published and 16 unpublished), yields a best-fitting linear ephemeris of BJDecl = 2,453,403.7611(2) + 0.269,374,43(2)E. We find a somewhat improved fit with a quadratic ephemeris given by: BJDecl = 2,453,403.7598 + 0.269,374,87 E - 2.0 × 10-11 E2, which suggests that the orbital period may be decreasing at a rate given by $\dot{P}\simeq -1.5\times {10}^{-10}$ .

Keywords: Eclipsing binary stars, Nova-like variable stars, Cataclysmic variable stars
LUCI: A Python Package for SITELLE Spectral Analysis. High-resolution optical integral field units (IFUs) are rapidly expanding our knowledge of extragalactic emission nebulae in galaxies and galaxy clusters. By studying the spectra of these objects-which include classic H II regions, supernova remnants, planetary nebulae, and cluster filaments-we are able to constrain their kinematics (velocity and velocity dispersion). In conjunction with additional tools, such as the BPT diagram, we can further classify emission regions based on strong emission-line flux ratios. LUCI is a simple-to-use python module intended to facilitate the rapid analysis of IFU spectra. LUCI does this by integrating well-developed pre-existing python tools such as astropy and scipy with new machine learning tools for spectral analysis. Furthermore, LUCI provides several easy-to-use tools to access and fit SITELLE data cubes.

Keywords: Software documentation, Open source software, Galaxy spectroscopy, Astronomy software
Candidate Type II Be X-Ray Binary Outbursts in NGC 6744. We present the discovery of two new X-ray transients in the galaxy NGC 6744. The properties of these transients are consistent with those of Type II outbursts of Be X-ray binaries, but further data will be required to confirm their nature.

Keywords: High mass x-ray binary stars, Spiral galaxies
Gemini Speckle Imaging of Dual Quasar Candidates. We observed the candidate dual quasar J2122-0026 with speckle interferometric imaging at the Gemini-North Observatory. Results of our one-hour high resolution 'Alopeke imaging observation agree with and confirm Hubble Space Telescope imaging of the pair separated at ~0"5. These observations show that sub-arcsec dual quasar candidates as faint as r ~ 19 can be observed and detected using speckle imaging at Gemini.

Keywords: Speckle interferometry, Quasars
New or Increased Cometary Activity in (2060) 95P/Chiron. Asteroid Terrestrial-impact Last Alert System (ATLAS) observations of Centaur (2060) 95P/Chiron show a brightening in the apparent magnitude not due rotational light curves or phase effects. This onset or enhancement of cometary activity started after 2021 February 8 UT and continued in later observations from 2021 June 18 UT onward. Recent ATLAS observations and deeper follow-up imaging obtained using the Las Cumbres Observatory 1.0 m robotic telescope network find no confirmed signature of coma or tail-like features.

Keywords: Sky surveys, Centaur group, Wide-field telescopes, Comets, Coma dust
Polarization Measurements of Selected Young Stars with Circumstellar Dusty Disks. BVRI polarization measurements of 14 selected young stars with circumstellar dust disks are presented. The interstellar polarization in the direction of these stars is not significant. The observed polarization data and its wavelength-dependence indicate that it is intrinsic, due to scattering by circumstellar, asymmetric dusty disks/envelopes.

Keywords: Herbig Ae/Be stars, Circumstellar matter, Starlight polarization, Pre-main sequence stars, Protoplanetary disks
Solar Neighborhood Exoplanet Host Stars within a Galactic Context. Ages, metallicities, and Galactic orbit parameters are considered for those stars with Henry Draper catalog designations that have been discovered to host planetary systems. There are quite a few such stars with above-solar metallicity and ages up to 4 Gyr older than the Sun. Some planet-hosting stars have Galactic orbits that take them within 4 kpc of the Galactic Center, while a substantial fraction attain displacements from the Galactic mid-plane consistent with the thick disk.

Keywords: Milky Way disk, Galactic archaeology, Planet hosting stars
Extinction Correction and the [Fe II] 1.26 μm/1.64 μm Intensity Ratio. From imaging observations of [Fe II] emission in Herbig-Haro objects, I find a lower limit to the zero-extinction [Fe II] 1.26 μm/1.64 μm intensity ratio of 2.6 and argue that this lower limit must be close to the true zero-extinction intensity ratio. My extinction determinations using this zero-extinction value yields results on well-studied HH objects consistent with results from other ionic-line spectra, whereas using nearly all theoretical values of [Fe II] 1.26 μm/1.64 μm in the literature gives rise to unphysical results.

Keywords: Herbig-Haro objects, Young stellar objects, Interstellar line emission
On the Demographics of Exoplanet Host Stars. The NASA TESS mission has provided the community with a plethora of new exoplanet host stars. These bright, nearby stars have been examined in detail in a number of studies and it has been determined that nearly one-half of the solar-like stars are binary. Two recent papers which examined 700 TESS exoplanet hosts have provided stellar properties for the stars, both single and binary. Herein, we provide a quantitative look at some properties of the stars, particularly searching for differences between the single versus binary (primary) host stars. We also compare the properties of the binary (primary) host stars themselves.

Keywords: Planetary system formation, Visual binary stars, Binary stars, High angular resolution
Evaluating and Enhancing Candidate Clocking Systems for CHIME/FRB VLBI Outriggers. As the Canadian Hydrogen Intensity Mapping Experiment (CHIME) has become the leading instrument for detecting Fast Radio Bursts (FRBs), CHIME/FRB Outriggers will use very-long-baseline interferometry (VLBI) to localize FRBs with milliarcsecond precision. The CHIME site uses a passive hydrogen maser frequency standard in order to minimize localization errors due to clock delay. However, not all outrigger stations will have access to a maser. This report presents techniques used to evaluate clocks for use at outrigger sites without a maser. More importantly, the resulting algorithm provides calibration methods for clocks that do not initially meet the stability requirements for VLBI, thus allowing CHIME/FRB Outriggers to remain true to the goal of having milliarcsecond precision.

Keywords: Very long baseline interferometry, Astronomical instrumentation, Radio transient sources, Radio astronomy, Radio pulsars
The Widefield Arecibo Virgo Extragalactic Survey: Early Results on Known Dark Sources. The Widefield Arecibo Virgo Extragalactic Survey (WAVES) was an ongoing H I survey of the Virgo Cluster with the Arecibo Observatory's 305 m William E. Gordon Telescope at the time of its structural failure. The full 20 square degrees of the southern field and 10 of the planned 35 square degrees of the northern field had been observed to full depth, adding to 25 square degrees observed to the same depth in the cluster by the Arecibo Galaxy Environment Survey. We here review what WAVES reveals about four optically dark H I structures that were previously discovered in the survey area, including two that are not seen despite being well above our detection limit.

Keywords: Virgo Cluster, H I line emission
The Study of Mass to Light Ratios in Cluster of Galaxies. Our analysis of observed Hickson Compact Groups shows that there is a strong and statistically significant (p = 0.002) relationship between mass to light ratio (M/LR) and group mass, with more massive compact groups having substantially higher M/LRs, scaling roughly with mass to the 0.76 ± 0.09 power. This relationship holds even after dropping clusters of galaxies whose log mass differs from the mean log mass by more than two standard deviations. For a sample of Abell clusters of galaxies, a similar but weaker relationship is observed, with more massive galaxies having a M/LR that scales with mass to the 0.73 ± 0.09 power (p = 0.010). This relationship implies that heavier galaxy clusters have dramatically higher fractions of dark matter.

Keywords: Galaxy clusters, Hickson compact group, Galactic and extragalactic astronomy, Abell clusters, Dark matter
Confirmation of a Dynamical Model for the TRAPPIST-1 Exoplanetary System. We present a new transit of TRAPPIST-1 d from 2021 August 25. The measured mid-point of this transit agrees with the prediction from a recently published dynamical model for the TRAPPIST-1 system and differs significantly from a naive prediction from a simple linear ephemeris. This difference underlines the importance for using dynamical models to predict future transit times in the TRAPPIST-1 system.

Keywords: Exoplanet astronomy, Transit photometry
Constructing Mixture Models for Sensitivity Estimates from Subsets of Separate Injections. I investigate the general question of how to construct a set of samples (found injections) from a mixture of samples from separate subpopulations in order to estimate search sensitivity via Monte Carlo sums. This is of general interest for catalog science, in which one must estimate a survey's sensitivity to different types of sources. Sensitivity estimates targeting different subpopulations or different observing periods may be combined to provide overarching estimates of the sensitivity through larger regions of parameter space. Specifically, I consider 2 cases: (i) when injections from subpopulations were conducted over the same span of time and (ii) when injections from subpopulations were conducted in non-overlapping periods. Any general collection of subpopulations can be decomposed into these cases.

Keywords: Surveys, Gravitational wave astronomy, Gravitational waves, Astronomical methods, Catalogs
Multiwavelength View of the M87 Black Hole Captured by the Event Horizon Telescope. In 2017, the first image of the center of the M87 galaxy was captured by the Event Horizon Telescope (EHT). It revealed a ring morphology and a size consistent with theoretical expectations for the light pattern around a weakly accreting supermassive black hole of ~6.5 billion solar masses. In parallel to the EHT measurements, an extensive multi-wavelength (MWL) campaign with ground- and space-based facilities from radio all the way up to the TeV energy range was organized. In this note we will give an overview of the results from this campaign. M87 was found to be in a historically low state. At X-ray energies the emission from the core dominates over HST-1. We present the most complete simultaneous, MWL spectrum of the active nucleus to date.

Keywords: Black hole physics, Galaxies, Jets, Black holes, High energy astrophysics, Stellar mass black holes, Radio galaxies, Astrophysical black holes
Long GMC Lifetimes: Using the Method and Data of Meidt et al. (2015) with a Correction. Meidt et al. derived short lifetimes of 20-30 Myr for giant molecular clouds (GMCs) in M51. Their novel approach utilizes a decline of the GMC population during their inter-arm passage from one spiral arm to the next. Using the inter-arm travel time ttravel as a fiducial clock, they converted the decline rate to GMC lifetimes. They implicitly adopted zero as the pattern speed of the spiral arms, resulting in a very short ttravel. However, it is well established that the spiral arm pattern in M51 is rotating, and that ttravel should be measured with respect to the rotating spiral pattern. Here we use the same method and data of Meidt et al. and re-evaluate GMC lifetimes by accounting for the pattern speed given by Meidt et al. This correction gives a longer ttravel, and consequently longer GMC lifetimes of 60-500 Myr.

Keywords: Giant molecular clouds, Galaxy dynamics
An Accurate Analytical Fit to the Gravitational-wave Inspiral Duration for Eccentric Binaries. I present an analytical fit to the duration of the inspiral of two point masses driven by gravitational-wave emission. The fit is accurate to within 3% over the entire range of initial eccentricities from 0 to 0.99999.

Keywords: Gravitational wave astronomy
K-band Luminosity Functions of IllustrisTNG300-1 Galaxies. This Research Note summarizes preliminary results, presented at the 238th AAS meeting, for the K-band luminosity functions (LFs) of IllustrisTNG300-1 galaxies. For MK ≥ -22, the simulation reproduces both the shape and amplitude of the LF for observed field galaxies. However, it significantly overproduces field galaxies with MK &lt; -22. For MK ≤ -22, the simulation reproduces the shape of the LF for observed cluster galaxies, however at fainter magnitudes the LF falls below a simple extrapolation of recent observations. For MK ≤ -22, the shapes of the LFs for red cluster galaxies and blue cluster galaxies agree reasonably well with observations, but neither is well-fitted by a Schechter function at fainter magnitudes. In addition, the faint-end slope of the LF in the inner regions of the clusters is significantly flatter than it is in the outer regions.

Keywords: Galaxy clusters, Galaxy luminosities
Evolution of the Gas Density in a Simulated Star-forming Cloud with Stellar Feedback. Star formation involves gravity, turbulence, magnetic fields, and feedback from new stars through jets, radiation and winds. The evolution of the density probability distribution function (ρ-PDF) is directly related to the star formation rate (SFR), forming the basis of several star formation models. We utilize two runs from the STARFORGE simulation suite that follow the evolution of molecular clouds, while resolving individual stars and including all gas and feedback physics. The two runs have different initial conditions, one is a periodic box with driven turbulence (Box), while the other is an isolated cloud without turbulent driving (Sphere). We find that the ρ-PDF for both runs is initially well-fit by a log-normal (LN) plus a power-law (PL) function. However, as the SFR peaks, the PDF for the Sphere run becomes well-fit by just a wide LN. Conversely, the Box run PDF remains well-fit by a LN+PL function for the entirety of the run.

Keywords: Computational astronomy, Star formation, Interstellar clouds, Interstellar medium
The Mean Underabundances of Carbon and Aluminum Over the Surface of 21 Com from Its Far-ultraviolet Spectra Recorded by IUE. The comparison of a coadded International Ultraviolet Explorer (IUE) far-ultraviolet spectrum of 21 Com (A3p SrCr) to that of the standard star α Psa (A3V) reveals large differences in the resonance and low-excitation lines of C I and Al II. All the lines of these species are significantly weaker in the mean spectrum of 21 Com. The synthesis of these lines consistently yields sizable underabundances for 21 Com of about 0.5 times the solar carbon, and 0.20 times solar for aluminum. Inspection of 10 individual spectra taken over the 24 hr monitoring of 21 Com with IUE on 1991 April 17 does not reveal convincing variations of the lines analyzed here between rotational phases 0.18 and 0.65 of the 2 days period, suggesting a uniform repartition of these 2 elements over the hemisphere of 21 Com observed then.

Keywords: Chemically peculiar stars, Chemical abundances
The Nature of the Sharp-lined A1 V Star HR 4138. The comparison of far-ultraviolet spectra taken years apart with the IUE shows that the FUV flux of HR 4138 is variable. An abundance analysis of High Accuracy Radial velocity Planet Searcher spectra reveals that the light elements (with Z less than 30) have solar or nearly solar abundances whereas heavier elements are overabundant. Inspection of the Transiting Exoplanet Survey Satellite lightcurves of HR 4138 suggests that the rotational period of HR 4138 may be close to 3 days.

Keywords: Stellar abundances, A stars
VeSPA: The SuperWASP Variable Star Photometry Archive. We present the first results from the SuperWASP Variable Stars (SVS) citizen science project. The photometry archive of the Wide Angle Search for Planets has previously been searched for periodic variations and the results of this search formed the basis of the SVS project on the Zooniverse. The SVS project asks volunteers to visually inspect light curve plots and categorize each one according to a broad classification scheme. Results from the first two years of SVS have now been published online as the SuperWASP Variable Star Photometry Archive (VeSPA). The archive can be browsed online, downloaded in full, or queried, filtered, and sorted to export a refined set of results. An interactive light curve viewer also allows any light curve to be folded at a user-defined period. Analysis of citizen science results and development of VeSPA features are both ongoing. Updated results will be published every six months.

Keywords: Pulsating variable stars, Surveys, Variable stars, Eclipsing binary stars, Catalogs
Discovery of a Uniquely Cool and Compact Source at 28 pc from the Sun. We present the discovery of what appears to be both a uniquely cool and old white dwarf (WD) within 30 pc of the Sun. DES J214756.46-403529.3 is detected in four separate surveys, 50° away from the Galactic Plane. The combination of its very low luminosity and spectral energy distribution suggests an object unlike any other astrophysical body currently known. Among 8000 of the nearest single objects in the immediate solar neighborhood, it appears completely isolated in multiple color-magnitude diagrams. The data seem compatible with an extremely old and cool WD with a helium dominated atmosphere and a mass around 0.7-0.8 M⊙ but spectroscopic follow-up is required to confirm its nature.

Keywords: Fundamental parameters of stars, White dwarf stars
Modeling of Engulfment Material in the Binary System HIP 71726/71737. A parameterized regression fit to precision differential abundances, [El/H], in the wide binary system HIP 71726/71737 accounts for the condensation temperature dependence with a high significance. This fit includes 27 elements, Carbon through Europium. We discuss conditions and the implications of a fit to [Li/H] with the same parameters. These results support the hypothesis of engulfment of earthlike material.

Keywords: Chemical abundances
Photometric Observations of KEPLER Mission's Eclipsing Binary EPIC 201458798 (V0337Leo). Two follow up observing sessions of Kepler's Eclipsing Binary star system EPIC 201458798 (from the K2 mission) were conducted in the Spring of 2018 and 2019 utilizing the 0.4 m subnet of the Los Cumbres Observatory Global Telescope network. The total duration of observations for each session (~77 days) was comparable with the duration of observations by the Kepler telescope ~80 days. 900-1000 images were obtained during each session with an integrating time around 1 minute, resulting in about 800 mag measurements per session. In contrast, the Kepler telescope provided almost continuous measurements of this star with an integration time per image of about 30 minutes, resulting in about 3250 photometric points. In contrast to the Kepler telescope measurements, which were conducted with one very broad filter, the observations in this study used four filters: B, V, ip, and rp. This data was processed and the period, time of minimum, and depth of the eclipses was determined. The results were compared with the data obtained by the Kepler telescope and other historical records.

Keywords: Eclipsing binary stars
θ<SUP>1</SUP> Ori C as a Medieval Bully: A Possible Very Recent Ejection in the Trapezium. We use Gaia EDR3 astrometry to propose that a dynamical interaction between the multiple system θ1 Ori C and θ1 Ori F ejected the latter as a walkaway star ~1100 yr ago (without deceleration) or somewhat later (with a more likely deceleration included). It is unclear whether the final 3D velocity of θ1 Ori F will be large enough to escape the Orion nebula cluster.

Keywords: Multiple stars, O stars, Young star clusters, Astrometry, Runaway stars
A Study of the Soft X-Ray Emission Lines in NGC 4151. II. The Internal Plasma Properties. We showcase a tool suite that enables the fitting of soft X-ray spectra in active galactic nuclei (AGNs), without the need for specialist software, allowing access to AGN physics for school students. While these standardized Python tools were useful for measuring velocities, they offered significantly fewer capabilities for radiative recombination continua, and R and G ratios, utilized to obtain the internal plasma properties within the outflowing wind seen in NGC 4151. Although further work is required for these tools to be used in outreach projects, we present findings of the plasma temperature and density in NGC 4151 spanning a 15 yr period.

Keywords: High resolution spectroscopy, Supermassive black holes, Active galactic nuclei
Quick-look Pipeline Lightcurves for 9.1 Million Stars Observed over the First Year of the TESS Extended Mission. We present a magnitude-limited set of lightcurves for stars observed over the Transiting Exoplanet Survey Satellite (TESS) Extended Mission, as extracted from full-frame images (FFIs) by MIT's Quick-Look Pipeline (QLP). QLP uses multi-aperture photometry to produce lightcurves for ~1 million stars each 27.4 days sector, which are then searched for exoplanet transits. The per-sector lightcurves for 9.1 million unique targets observed over the first year of the Extended Mission (Sectors 27-39) are available as High-Level Science Products (HLSPs) on the Mikulski Archive for Space Telescopes. As in our TESS Primary Mission QLP HLSP delivery, our available data products include both raw and detrended flux time series for all observed stars brighter than TESS magnitude T = 13.5, providing the community with one of the largest sources of FFI-extracted lightcurves to date.

Keywords: Transit photometry, Light curves, Exoplanets
Pluto's Resonant Orbit Visualized in 4D. Orbital resonance phenomena are notoriously difficult to communicate in words due to the complex dynamics arising from the interplay of gravity and orbital angular momentum. A well known example is Pluto's 3:2 mean motion resonance with Neptune. We have developed a PYTHON software tool to visualize the full three-dimensional aspects of Pluto's resonant orbital dynamics over time. The visualizations include still images and animated movies. By contrasting Pluto's resonant dynamics with the dynamics of a nearby non-resonant orbit, this tool enables better understanding and exploration of complex planetary dynamics phenomena.

Keywords: Neptune, Small Solar System bodies, Solar system, Orbital resonances, Resonant Kuiper belt objects, Gravitational interaction, Celestial mechanics, Three-body problem, Pluto, Plutinos, Astronomy data visualization, N-body simulations