Sazuna/UAT_keywords huggingface dataset:
TESS Observations of Kepler Systems with Transit Timing Variations. We identify targets in the Kepler field that may be characterized by transit timing variations and are detectable by the Transiting Exoplanet Survey Satellite (TESS). Despite the reduced signal-to-noise ratio of TESS transits compared to Kepler, we recover 48 transits from 13 systems in Sectors 14, 15, 26, 40 and 41. We find strong evidence of a nontransiting perturber orbiting Kepler-396 (KOI-2672) and explore two possible cases of a third planet in that system that could explain the measured transit times. We update the ephemerides and mass constraints where possible at KOI-70 (Kepler-20), KOI-82 (Kepler-102), KOI-94 (Kepler-89), KOI-137 (Kepler-18), KOI-244 (Kepler-25), KOI-245 (Kepler-37), KOI-282 (Kepler-130), KOI-377 (Kepler-9), KOI-620 (Kepler-51), KOI-806 (Kepler-30), KOI-1353 (Kepler-289), and KOI-1783 (Kepler-1662).

Keywords: Exoplanet astronomy, Light curves, Transit timing variation method, Photometry
Molecular Cloud Populations in the Context of Their Host Galaxy Environments: A Multiwavelength Perspective. We present a rich, multiwavelength, multiscale database built around the PHANGS-ALMA CO (2 - 1) survey and ancillary data. We use this database to present the distributions of molecular cloud populations and subgalactic environments in 80 PHANGS galaxies, to characterize the relationship between population-averaged cloud properties and host galaxy properties, and to assess key timescales relevant to molecular cloud evolution and star formation. We show that PHANGS probes a wide range of kpc-scale gas, stellar, and star formation rate (SFR) surface densities, as well as orbital velocities and shear. The population-averaged cloud properties in each aperture correlate strongly with both local environmental properties and host galaxy global properties. Leveraging a variable selection analysis, we find that the kpc-scale surface densities of molecular gas and SFR tend to possess the most predictive power for the population-averaged cloud properties. Once their variations are controlled for, galaxy global properties contain little additional information, which implies that the apparent galaxy-to-galaxy variations in cloud populations are likely mediated by kpc-scale environmental conditions. We further estimate a suite of important timescales from our multiwavelength measurements. The cloud-scale freefall time and turbulence crossing time are ~5-20 Myr, comparable to previous cloud lifetime estimates. The timescales for orbital motion, shearing, and cloud-cloud collisions are longer, ~100 Myr. The molecular gas depletion time is 1-3 Gyr and shows weak to no correlations with the other timescales in our data. We publish our measurements online, and expect them to have broad utility to future studies of molecular clouds and star formation.

Keywords: Millimeter astronomy, Star formation, Molecular clouds, Disk galaxies
Environmental Effects in Herschel Observations of the Ionized Carbon Content of Star-forming Dwarf Galaxies in the Virgo Cluster. We use archival Herschel data to examine the singly ionized carbon ([C II]) content of 14 star-forming dwarf galaxies in the Virgo cluster. We use spectral energy distribution fits to far-infrared, mid-infrared, near-infrared, optical, and ultraviolet data to derive the total infrared continuum (TIR) for these galaxies. We compare the [C II]/TIR ratio for dwarf galaxies in the central part of Virgo to those in the southern part of the cluster and to galaxies with similar TIR luminosities and metallicities in the Herschel Dwarf Galaxy Survey (DGS) sample of field dwarf galaxies to look for signs of [C II] formation independent of star formation. Our analysis indicates that the sample of Virgo dwarfs in the central part of the cluster has significantly higher values of [C II]/TIR than the sample from the southern part of the cluster and the sample from the DGS, while the southern sample is consistent with the DGS. This [C II]/TIR excess implies that a significant fraction of the [C II] in the dwarf galaxies in the cluster center has an origin other than star formation and is likely to be due to environmental processes in the central part of the cluster. We also find a surprisingly strong correlation between [C II]/TIR and the local ram pressure felt by the dwarf galaxies in the cluster. In this respect, we claim that the excess [C II] we see in these galaxies is likely to be due to formation in ram-pressure shocks. * Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Keywords: CII region, Ram pressure stripped tails, Virgo Cluster, Dwarf galaxies, Far infrared astronomy
Evaluating the V-band Photometric Metallicity with Fundamental Mode RR Lyrae in the Kepler Field. The aim of this work is to evaluate the performance of photometric metallicity [Fe/H], determined based on V-band light curves photometrically transformed from the gr-band light curves. We tested this by using a set of homogeneous samples of fundamental mode RR Lyrae located in the Kepler field. It was found that the color term is necessary in such photometric transformation. We demonstrated that when including the color term the determined photometric [Fe/H] are in good agreement with the spectroscopic [Fe/H], either based on the calibrated or the transformed V-band light curves. We also tested the impact of Blazhko RR Lyrae in determining the photometric [Fe/H], and found that Blazhko RR Lyrae can give consistent photometric [Fe/H]. Finally, we derived independent gVr-band [Fe/H]-ϕ 31-P relations (where ϕ 31 and P are the Fourier parameter and pulsation period, respectively) using our light curves. The V-band relation is in good agreement with the most recent determination given in the literature.

Keywords: Light curves, RR Lyrae variable stars, Metallicity
Supporting Evidence for a Galactic Lyα Background from Cassini UVIS Data. Cassini UVIS interplanetary hydrogen Lyα measurements from 2003 to 2004, obtained from a heliospheric downwind to sidewind location on approach to Saturn and during the first Saturn orbit, are presented and fit by a heliospheric hot density model with solar illumination. Adding the recently proposed 43 ± 3 Rayleigh (R) isotropic galactic hydrogen Lyα signal derived from New Horizons data improves our model's ability to fit the observed Cassini "27 day" signal modulations from both upwind and downwind directions. Our modeling of the UVIS data favors a galactic Lyα background of ~40-100R over a model with no significant galactic background.

Keywords: Interstellar medium wind
The All-sky Spectrometer of Hot Cosmic Plasma. The main instruments for analyzing the processes occurring in cosmic plasma are energy and mass analyzers of charged particle beams. The analyzers' operation is based on the separation of charged particles according to the energies of their motion or their masses in electric or magnetic fields. Currently, the top-hat analyzer is considered the main instrument for obtaining information about the state of cosmic plasma. However, it has a number of disadvantages: a significant time cycle for registering angular dependences in a total solid angle of 4π sr and low accuracy of determining the polar angles, which are associated with the need to rotate the analyzer during measurements. Over the past 20 years, plasma analyzers with a large viewing angle have been developed as an alternative to the top-hat analyzer. The design of the analyzer proposed in this work is capable of measuring plasma characteristics in a solid angle of 2π sr in one act of data registration. The all-sky spectrometer of hot cosmic plasma consists of two stages: the first stage is a conical lens of an original design, which serves to transform an extremely wide entrance flow of particles into a narrow cone-shaped beam; the second hexapole-cylindrical stage plays the role of an energy analyzer of a narrow cone-shaped flow. The paper describes the calculations and modeling of the proposed analyzer on the basis of original numerical and approximate analytical methods for designing systems of electron and ion optics. The main parameters of the device are calculated.

Keywords: Spectrometers, Space plasmas
Satellite Galaxies' Drag on Field Stars in the Milky Way. With Gaia EDR3 data, velocity dispersion of Milky Way field stars around satellite galaxies has been investigated. We have fitted velocity dispersion against the distance to the satellite galaxy and found the gradient of velocity dispersion is related to the mass of the satellite galaxy. With order-of-magnitude approximations, a linear correlation has been fitted between the mass of the satellite galaxy and the gradient of velocity dispersion caused by its gravitational drag. Though our result is an observational qualitative result, it shows a better relation could be obtained with more observations in the future.

Keywords: Stellar kinematics, Galaxy masses, Dwarf galaxies
Identifying Exoplanets with Deep Learning. IV. Removing Stellar Activity Signals from Radial Velocity Measurements Using Neural Networks. Exoplanet detection with precise radial velocity (RV) observations is currently limited by spurious RV signals introduced by stellar activity. We show that machine-learning techniques such as linear regression and neural networks can effectively remove the activity signals (due to starspots/faculae) from RV observations. Previous efforts focused on carefully filtering out activity signals in time using modeling techniques like Gaussian process regression. Instead, we systematically remove activity signals using only changes to the average shape of spectral lines, and use no timing information. We trained our machine-learning models on both simulated data (generated with the SOAP 2.0 software) and observations of the Sun from the HARPS-N Solar Telescope. We find that these techniques can predict and remove stellar activity both from simulated data (improving RV scatter from 82 to 3 cm s-1) and from more than 600 real observations taken nearly daily over 3 yr with the HARPS-N Solar Telescope (improving the RV scatter from 1.753 to 1.039 m s-1, a factor of ~1.7 improvement). In the future, these or similar techniques could remove activity signals from observations of stars outside our solar system and eventually help detect habitable-zone Earth-mass exoplanets around Sun-like stars.

Keywords: Exoplanet astronomy, Radial velocity, Convolutional neural networks
TOI-3714 b and TOI-3629 b: Two Gas Giants Transiting M Dwarfs Confirmed with the Habitable-zone Planet Finder and NEID. We confirm the planetary nature of two gas giants discovered by the Transiting Exoplanet Survey Satellite to transit M dwarfs. TOI-3714 (V = 15.24, J = 11.74) is an M2 dwarf hosting a hot Jupiter (M  p  = 0.70 ± 0.03 M  J  and R  p  = 1.01 ± 0.03 R  J ) on an orbital period of 2.154849 ± 0.000001 days with a resolved white dwarf companion. TOI-3629 (V = 14.63, J = 11.42) is an M1 dwarf hosting a hot Jupiter (M  p  = 0.26 ± 0.02 M  J  and R  p  =0.74 ± 0.02 R  J ) on an orbital period of ${3.936551}_{-0.000006}^{+0.000005}$ days. We characterize each transiting companion using a combination of ground-based and space-based photometry, speckle imaging, and high-precision velocimetry from the Habitable-zone Planet Finder and the NEID spectrographs. With the discovery of these two systems, there are now nine M dwarfs known to host transiting hot Jupiters. Among this population, TOI-3714 b (T eq = 750 ± 20 K and TSM = 98 ± 7) and TOI-3629 b (T eq = 690 ± 20 K and TSM = 80 ± 9) are warm gas giants amenable to additional characterization with transmission spectroscopy to probe atmospheric chemistry and, for TOI-3714, obliquity measurements to probe formation scenarios.

Keywords: Extrasolar gaseous giant planets, Exoplanet systems
Constraining the Size of the Circumgalactic Medium Using the Transverse Autocorrelation Function of C IV Absorbers in Paired Quasar Spectra. The circumgalactic medium (CGM) plays a vital role in the formation and evolution of galaxies, acting as a lifeline between galaxies and the surrounding intergalactic medium. In this study, we leverage a unique sample of quasar pairs to investigate the properties of the CGM with absorption line tomography. We present a new sample of medium-resolution Keck/ESI, Magellan/MagE, and VLT/XSHOOTER spectra of 29 quasar pairs at redshift 2 &lt; z &lt; 3. We supplement the sample with additional spectra of 32 pairs from the literature, creating a catalog of 61 quasar pairs with angular separations between 1.″7 and 132.″9 and projected physical separations (r ⊥) between 14 kpc and 887 kpc. We construct a catalog of 906 metal-line absorption doublets of C IV (λλ1548, 1550) with equivalent widths ranging from 6 m Å ≤ W  r,1550 ≤ 2053 m Å. The best-fit linear model to the log-space equivalent width frequency distribution ( $\mathrm{log}f({W}_{r})=m\mathrm{log}({W}_{r})+b$ ) of the sample yields coefficients of m = -1.44 ± 0.16 and b = -0.43 ± 0.16. To constrain the projected extent of C IV, we calculate the transverse autocorrelation function. The flattening of the autocorrelation function at low r ⊥ provides a lower limit for the coherence length of the metal enriched CGM-on the order of 200 h -1 comoving kpc. This physical size constraint allows us to refine our understanding of the metals in the CGM, where the extent of C IV in the CGM depends on gas flows, feedback, timescale of metal injection and mixing, and the mass of the host galaxies.

Keywords: Intergalactic medium, Quasar absorption line spectroscopy, Circumgalactic medium
Toward a Data-driven Model of the Sky from Low Earth Orbit as Observed by the Hubble Space Telescope. The sky observed by space telescopes in Low Earth Orbit (LEO) can be dominated by stray light from multiple sources including Earth, Sun, and Moon. This stray light presents a significant challenge to missions that aim to make a secure measurement of the extragalactic background light (EBL). In this work, we quantify the impact of stray light on sky observations made by the Hubble Space Telescope (HST) Advanced Camera for Surveys. By selecting on orbital parameters, we successfully isolate images with sky that contain minimal and high levels of earthshine. In addition, we find weather observations from CERES satellites correlate with the observed HST sky surface brightness indicating the value of incorporating such data to characterize the sky. Finally, we present a machine-learning model of the sky trained on the data used in this work to predict the total observed sky surface brightness. We demonstrate that our initial model is able to predict the total sky brightness under a range of conditions to within 3.9% of the true measured sky. Moreover, we find that the model matches the stray-light-free observations better than current physical zodiacal light models.

Keywords: Diffuse radiation, Zodiacal cloud, Cosmic background radiation
Inferring Exoplanet Disequilibria with Multivariate Information in Atmospheric Reaction Networks. Inferring properties of exoplanets from their atmospheres presents technical challenges in data collection due to low resolution and low signal-to-noise ratio (S/N) and theoretical challenges in the predictions made from forward-modeling due to errors introduced via incomplete or inaccurate assumptions in atmospheric physics and chemistry. The combination of these factors makes developing techniques to identify the most predictive features robust to low S/N and model error an increasingly important challenge for exoplanet science. Here we implement a multivariate approach to identify optimal predictors of the state of disequilibria. As a case study we focus on the prediction of vertical mixing (parameterized as eddy diffusion) in hot Jupiter atmospheres. We use multivariate information contained in molecular abundances, reaction network topology, and Gibbs free energy to demonstrate the variation in prediction efficacy of the vertical mixing coefficient (K zz) from different model information. While current approaches target inferring molecular abundances from spectral data, our results indicate that the set of optimal predictors of K zz varies with planetary properties such as irradiation temperature and metallicity. In most cases, multivariate data composed of network topological variables, which capture system-level features, perform as well as the set of optimal predictors and better than any individual variable. We discuss future directions, where identifying the set of optimal predictors should be useful for quantitatively ranking atmospheres in terms of their distance from thermochemical equilibrium, provide target variables for the development of new tools for inverse modeling, and provide applications to the longer-term goal of detection of disequilibria associated with life.

Keywords: Exoplanet atmospheres
New Insights into the Structure of Open Clusters in the Gaia Era. With the help of Gaia data, it is noted that in addition to the core components, there are low-density outer halo components in the extended region of open clusters. In order to study the extended structure beyond the core radius of the cluster (~10 pc), based on Gaia Early Data Release 3, taking up to 50 pc as the searching radius, we use the pyUPMASK algorithm to redetermine the member stars of the open cluster within 1-2 kpc. We obtain the member stars of 256 open clusters, especially those located in the outer halo region of open clusters. Furthermore, we find that the radial density profile in the outer region for most open clusters deviates from the Kings profile. In order to better describe the internal and external structural characteristics of open clusters, we propose a two-component model: a core component with a King model distribution and an outer halo component with a logarithmic Gaussian distribution, and then suggest using four radii (r  c , r  t , r  o , r  e ) for describing the structure and distribution profile of star clusters, where r  t  and r  e  represent the boundaries of the core component and outer halo component, respectively. Finally, we provide a catalog of 256 clusters with structural parameters. In addition, our study shows the sizes of these radii are statistically linearly related, which indicates that the inner and outer regions of the cluster are interrelated and follow similar evolutionary processes. Further, we show that the structure of two components can be used to better trace the cluster evolution properties at different stages.

Keywords: Open star clusters
Dependence of Molecular Cloud Samples on Angular Resolution, Sensitivity, and Algorithms. In this work, we investigate the observational and algorithmic effects on molecular cloud samples identified from position-position-velocity (PPV) space. By smoothing and cutting off the high quality data of the Milky Way Imaging Scroll Painting (MWISP) survey, we extract various molecular cloud samples from those altered data with the DBSCAN (density-based spatial clustering of applications with noise) algorithm. Those molecular cloud samples are subsequently used to gauge the significance of sensitivity, angular/velocity resolution, and DBSCAN parameters. Two additional surveys, the FCRAO Outer Galaxy Survey and the CfA-Chile 1.2 m complete CO (CfA-Chile) survey, are used to verify the MWISP results. We found that molecular cloud catalogs are not unique and that the catalog boundary and therefore the sample size show strong variation with angular resolution and sensitivity. At low angular resolution (large beam sizes), molecular clouds merge together in PPV space, while a low sensitivity (high cutoffs) misses small faint molecular clouds and takes bright parts of large molecular clouds as single ones. At high angular resolution and sensitivity, giant molecular clouds (GMCs) are resolved into individual clouds, and their diffuse components are also revealed. Consequently, GMCs are more appropriately interpreted as clusters or aggregates of molecular clouds, i.e., GMCs represent molecular cloud samples themselves.

Keywords: Interstellar molecules, Observational astronomy, Molecular clouds, Astronomy data analysis, Giant molecular clouds, Extragalactic astronomy
Determining Which Binary Component Hosts the TESS Transiting Planet. The NASA TESS mission has discovered many transiting planets orbiting bright nearby stars, and high-resolution imaging studies have revealed that a number of these exoplanet hosts reside in binary or multiple star systems. In such systems, transit observations alone cannot determine which star in the binary system actually hosts the orbiting planet. The knowledge of which star the planet orbits is necessary for determining accurate physical properties for the planet, especially its true radius and mean bulk density. We derived the mean stellar densities for the components of 23 binary systems using the light curve transit shape and the binary flux ratio from speckle imaging, then tested the consistency with stellar models to determine which component is the host star. We found that 70% of the TESS transiting planets in our sample orbit the primary star.

Keywords: High angular resolution, Exoplanets, Speckle interferometry
Dynamical Star-forming History of Per OB2. We analyze the internal dynamics of young stars toward Perseus using Gaia EDR3 data, including Per OB2 and California Cloud. Interpreting the current dynamics, we speculate that Per OB2 may have formed from two separate clouds that have begun forming stars in close proximity to each other. IC 348 is caught in the middle between the two of them, inheriting kinematics of both, and it stands out as a possible site of cloud-cloud interaction. We also consider the possibility of a past supernova in Per OB2-while one has likely occurred, it does not appear to have caused any obvious triggered star formation, but it has created a shock that has swept the molecular gas away from IC 348. Finally, we examine a recently proposed shell between Taurus and Perseus. While its origin is unknown, we find no support for an expanding bubble in stellar kinematics, nor can we identify a likely progenitor for a supernova that may have caused it, disfavoring this scenario in the formation of this apparent shell.

Keywords: Star forming regions, Young star clusters, Interstellar dynamics, Proper motions
Speckle Interferometry at SOAR in 2021. The speckle interferometry program at the the 4.1 m Southern Astrophysical Research Telescope (SOAR), which started in 2008, now has accumulated over 30,300 individual observations of 12,700 distinct targets. Its main goal is to monitor orbital motion of close binaries, including members of high-order hierarchies and low-mass dwarfs in the solar neighborhood. The results from 2021 are published here, totaling 2623 measurements of 2123 resolved pairs and nonresolutions of 763 targets. The median measured separation is 0.″21, and 75 pairs were closer than 30 mas. The calibration of scale and orientation is based on the observations of 103 wide pairs with well-modeled motion. These calibrators are compared to the latest Gaia data release, and minor (0.5%) systematic errors were rectified, resulting in accurate relative positions with typical errors on the order of 1 mas. Using these new measurements, orbits of 282 binaries are determined here (54 first determinations and 228 corrections). We resolved for the first time 50 new pairs, including subsystems in known binaries. A list of 94 likely spurious pairs unresolved at SOAR (mostly close Hipparcos binaries) is also given.

Keywords: Multiple stars, Visual binary stars, Orbital elements