Sazuna/UAT_keywords huggingface dataset:
On the Chemical Abundance of HR 8799 and the Planet c. Comparing chemical abundances of a planet and the host star reveals the origin and formation pathway of the planet. Stellar abundance is measured with high-resolution spectroscopy. Planet abundance, on the other hand, is usually inferred from low-resolution data. For directly imaged exoplanets, the data are available from a slew of high-contrast imaging/spectroscopy instruments. Here, we study the chemical abundance of HR 8799 and its planet c. We measure stellar abundance using LBT/PEPSI (R = 120,000) and archival HARPS data: stellar [C/H], [O/H], and C/O are 0.11 ± 0.12, 0.12 ± 0.14, and ${0.54}_{-0.09}^{+0.12}$ , all consistent with solar values. We conduct atmospheric retrieval using newly obtained Subaru/CHARIS data together with archival Gemini/GPI and Keck/OSIRIS data. We model the planet spectrum with petitRADTRANS and conduct retrieval using PyMultiNest. Retrieved planetary abundance can vary by ∼0.5 dex, from sub-stellar to stellar C and O abundances. The variation depends on whether strong priors are chosen to ensure a reasonable planet mass. Moreover, comparison with previous works also reveals inconsistency in abundance measurements. We discuss potential issues that can cause the inconsistency, e.g., systematics in individual data sets and different assumptions in the physics and chemistry in retrieval. We conclude that no robust retrieval can be obtained unless the issues are fully resolved.

Keywords: Exoplanet atmospheric composition , Chemically peculiar giant stars, Abundance ratios, Stellar abundances, Planetary atmospheres, Chemical abundances, Peculiar variable stars, Coronagraphic imaging, Direct imaging, Exoplanet detection methods, Chemically peculiar stars, Stellar atmospheres
Follow-up Studies of Five Cataclysmic Variable Candidates Discovered by LAMOST. We report follow-up observations of five cataclysmic variable candidates from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) published by Hou et al. LAMOST J024048.51+195226.9 is the most unusual of the five; an early-M type secondary star contributes strongly to its spectrum, and its spectral and photometric behavior are strikingly reminiscent of the hitherto-unique propeller system AE Aqr. We confirm that a 7.34 hr period discovered in the Catalina survey data is orbital. Another object, LAMOST J204305.95+341340.6, appears to be a near twin of the novalike variable V795 Her, with an orbital period in the so-called 2-3 hr "gap." LAMOST J035913.61+405035.0 is evidently an eclipsing, weakly outbursting dwarf nova with a 5.48 hr period. Our spectrum of LAMOST J090150.09+375444.3 is dominated by a late-type secondary and shows weak, narrow Balmer emission moving in phase with the absorption lines, but at lower amplitude; we do not see the He II λ4686 emission evident in the published discovery spectrum. We again confirm that a period from the Catalina data, in this case 6.80 hr, is orbital. LAMOST J033940.98+414805.7 yields a radial-velocity period of 3.54 hr, and its spectrum appears to be typical of novalike variables in this period range. The spectroscopically selected sample from LAMOST evidently includes some interesting cataclysmic variables that have been unrecognized until now, apparently because of the relatively modest range of their photometric variations.

Keywords: Eclipsing binary stars, Nova-like variable stars, Cataclysmic variable stars
The Dynamics of the Wide-angle Tailed (WAT) Galaxy Cluster A562. We present the first in-depth dynamical analysis of the archetypal wide-angle tailed (WAT) cluster A562. We have combined Gemini observations with archival data from the literature to form a sample of 76 cluster members and derived a mean redshift of 0.1088 ± 0.0004 and a velocity dispersion of 919 ± 116 km s-1. This relatively large velocity dispersion suggests either a very massive cluster (Mdyn &gt; 6.9 × 1014 M☉) and/or a merger system. The merger model is supported by a non-Gaussian galaxy velocity distribution, an elongated spatial distribution of likely cluster members, and an elongated X-ray emitting gas. This scenario would generate the bulk flow motion of the intracluster medium that can exert enough ram pressure to bend the radio jets. Thus, our observations support the model in which a recent off-axis merger event produced the cluster wide conditions needed to shape the WAT in A562.

Keywords: Galaxy clusters, Extragalactic radio sources, Radio galaxies, Tailed radio galaxies
TOI-824 b: A New Planet on the Lower Edge of the Hot Neptune Desert. We report the detection of a transiting hot Neptune exoplanet orbiting TOI-824 (SCR J1448-5735), a nearby (d = 64 pc) K4V star, using data from the Transiting Exoplanet Survey Satellite. The newly discovered planet has a radius Rp = 2.93 ± 0.20 ${R}_{\oplus }$ and an orbital period of 1.393 days. Radial velocity measurements using the Planet Finder Spectrograph and the High Accuracy Radial velocity Planet Searcher spectrograph confirm the existence of the planet, and we estimate its mass to be 18.47 ± 1.84 ${M}_{\oplus }$ . The planet's mean density is ${\rho }_{{\rm{p}}}$ = 4.03 ${}_{-0.78}^{+0.98}$ ${\rm{g}}\,{\mathrm{cm}}^{-3}$ , making it more than twice as dense as Neptune. TOI-824 b's high equilibrium temperature makes the planet likely to have a cloud-free atmosphere, and thus it is an excellent candidate for follow-up atmospheric studies. The detectability of TOI-824 b's atmosphere from both ground and space is promising and could lead to the detailed characterization of the most irradiated small planet at the edge of the hot Neptune desert that has retained its atmosphere to date.

Keywords: Stellar properties, Exoplanets, Radial velocity, Exoplanet astronomy, Exoplanet detection methods, Transit photometry
The Sizes of z ∼ 9-10 Galaxies Identified in the Brightest of Reionizing Galaxies (BoRG) Survey. Redshift z = 9-10 object selection is the effective limit of Hubble Space Telescope (HST) imaging capability, even when confirmed with Spitzer. If only a few photometry data points are available, it becomes attractive to add criteria based on their morphology in these J- and H-band images. One could do so through visual inspection, a size criterion, or alternate morphometrics. We explore a vetted sample of Brightest of Reionizing Galaxies (BoRG) z ∼ 9 and z ∼ 10 candidate galaxies and the object rejected by Morishita+ to explore the utility of a size criterion in z = 9-10 candidate selection. A stringent, point-spread function (PSF)-corrected effective radius criterion ( ${r}_{e}\lt 0\buildrel{\prime\prime}\over{.} 3$ ) would result in the rejection of 65%-70% of the interlopers visually rejected by Morishita et al. It may also remove up to ∼20% of bona fide brightest ( $L\gg {L}^{* }$ ) z = 9 or 10 candidates from a BoRG selected sample based on the Mason et al. luminosity functions, assuming the Holwerda et al. $z\sim 9$ size-luminosity relation. We argue that including a size constraint in lieu of a visual inspection may serve in wide-field searches for these objects in, e.g., Euclid or HST archival imaging with the understanding that some brightest ( $L\gg {L}^{* }$ ) candidates may be missed. The sizes of the candidates found by Morishita et al. follow the expected size distribution of z ∼ 9 for bright galaxies, consistent with the log normal in Shibuya et al. and single objects. Two candidates show high star formation surface density ( ${{\rm{\Sigma }}}_{\mathrm{SFR}}\gt 25{M}_{\odot }\,{\mathrm{kpc}}^{-2}$ ) and all merit further investigation and follow-up observations.

Keywords: Galaxy formation, Galaxy distances, Galaxy classification systems, Galaxy stellar content, Galactic and extragalactic astronomy, Galaxy evolution, Lyman-break galaxies, High-redshift galaxies, Galaxies, Galaxy radii
Systematic Phase Curve Study of Known Transiting Systems from Year One of the TESS Mission. We present a systematic phase curve analysis of known transiting systems observed by the Transiting Exoplanet Survey Satellite (TESS) during year one of the primary mission. Using theoretical predictions for the amplitude of the planetary longitudinal atmospheric brightness modulation, stellar ellipsoidal distortion and Doppler boosting, as well as brightness considerations to select targets with likely detectable signals, we applied a uniform data processing and light-curve modeling framework to fit the full-orbit phase curves of 22 transiting systems with planet-mass or brown dwarf companions, including previously published systems. Statistically significant secondary eclipse depths and/or atmospheric brightness modulation amplitudes were measured for HIP 65A, WASP-18, WASP-19, WASP-72, WASP-100, WASP-111, WASP-121, and WASP-122/KELT-14. For WASP-100b, we found marginal evidence that the brightest region of the atmosphere is shifted eastward away from the substellar point. We detected significant ellipsoidal distortion signals in the light curves of HIP 65A, TOI-503, WASP-18, and WASP-30, with HIP 65A, TOI-503 and WASP-18 also exhibiting Doppler boosting. The measured amplitudes of these signals agree with the predictions of theoretical models. Combining the optical secondary eclipse depths with previously published Spitzer 3.6 and 4.5 μm measurements, we derived dayside brightness temperatures and visible-light geometric albedos for a subset of the analyzed systems. We also calculated updated transit ephemerides combining the transit timings from the TESS light curves with previous literature values.

Keywords: Exoplanet astronomy, Exoplanet atmospheres
Discovery of a Nearby Young Brown Dwarf Disk. We report the discovery of the youngest brown dwarf with a disk at 102 pc from the Sun, WISEA J120037.79-784508.3 (W1200-7845), via the Disk Detective citizen science project. We establish that W1200-7845 is located in the ${3.7}_{-1.4}^{+4.6}$ Myr old ɛ Cha association. Its spectral energy distribution (SED) exhibits clear evidence of an infrared (IR) excess, indicative of the presence of a warm circumstellar disk. Modeling this warm disk, we find the data are best fit using a power-law description with a slope α = -0.94, which suggests that it is a young, Class II type disk. Using a single blackbody disk fit, we find ${T}_{\mathrm{eff},\mathrm{disk}}=521\,K$ and ${L}_{\mathrm{IR}}/{L}_{* }=0.14$ . The near-IR spectrum of W1200-7845 matches a spectral type of M6.0 $\gamma \,\pm $ 0.5, which corresponds to a low surface gravity object, and lacks distinctive signatures of strong Paβ or Brγ accretion. Both our SED fitting and spectral analysis indicate that the source is cool (Teff = 2784-2850 K), with a mass of 42-58 MJup, well within the brown dwarf regime. The proximity of this young brown dwarf disk makes the system an ideal benchmark for investigating the formation and early evolution of brown dwarfs.

Keywords: Brown dwarfs, Circumstellar disks
The Nebula N103B in the LMC Contains Parts of Two Supernova Remnants. The nebula N103B in the Large Magellanic Cloud consists of a previously identified small diameter supernova remnant (SNR) on its northeastern edge and a bright eastern arc with a fainter western shell together covering a total of about 8 × 5' at the canonical distance of 50 kpc. The latter also has a nonthermal radio spectrum and is apparently another SNR. I propose that the small bright northeastern SNR be renamed N103B-NE and the newly identified large SNR be called N103B-extended.

Keywords: Supernova remnants, Discrete radio sources, Large Magellanic Cloud
MIRC-X: A Highly Sensitive Six-telescope Interferometric Imager at the CHARA Array. Michigan InfraRed Combiner-eXeter (MIRC-X) is a new highly sensitive six-telescope interferometric imager installed at the CHARA Array that provides an angular resolution equivalent of up to a 330 m diameter baseline telescope in J- and H-band wavelengths ( $\tfrac{\lambda }{2B}\sim 0.6$ mas). We upgraded the original Michigan InfraRed Combiner (MIRC) instrument to improve sensitivity and wavelength coverage in two phases. First, a revolutionary sub-electron noise and fast-frame-rate C-RED ONE camera based on an SAPHIRA detector was installed. Second, a new-generation beam combiner was designed and commissioned to (i) maximize sensitivity, (ii) extend the wavelength coverage to J band, and (iii) enable polarization observations. A low-latency and fast-frame-rate control software enables high-efficiency observations and fringe tracking for the forthcoming instruments of the CHARA Array. Since mid-2017, MIRC-X has been offered to the community and has demonstrated best-case H-band sensitivity down to 8.2 correlated magnitude. MIRC-X uses single-mode fibers to coherently combine the light from six telescopes simultaneously with an image-plane combination scheme and delivers a visibility precision better than 1%, and closure phase precision better than 1°. MIRC-X aims at (i) imaging protoplanetary disks, (ii) detecting exoplanets with precise astrometry, and (iii) imaging stellar surfaces and starspots at an unprecedented angular resolution in the near-infrared. In this paper, we present the instrument design, installation, operation, and on-sky results, and demonstrate the imaging capability of MIRC-X on the binary system ι Peg. The purpose of this paper is to provide a solid reference for studies based on MIRC-X data and to inspire future instruments in optical interferometry.

Keywords: Starspots, Binary stars, Astronomy data acquisition, Very long baseline interferometry, Interferometers, Astronomy data analysis, Astronomical detectors, Young stellar objects, Astronomical instrumentation, Exoplanet detection methods, Michelson interferometry, Astronomy data reduction
Measuring Transit Signal Recovery in the Kepler Pipeline. IV. Completeness of the DR25 Planet Candidate Catalog. In this work we empirically measure the detection efficiency of the Kepler pipeline used to create the final Kepler threshold crossing event and planet candidate catalogs, a necessary ingredient for occurrence-rate calculations using these lists. By injecting simulated signals into the calibrated pixel data and processing those pixels through the pipeline as normal, we quantify the detection probability of signals as a function of their signal strength and orbital period. In addition, we investigate the dependence of the detection efficiency on parameters of the target stars and their location in the Kepler field of view. We find that the end-of-mission version of the Kepler pipeline returns to a high overall detection efficiency, averaging a 90%-95% rate of detection for strong signals across a wide swathe variety of parameter space. We find a weak dependence of the detection efficiency on the number of transits contributing to the signal and the orbital period of the signal, and a stronger dependence on the stellar effective temperature and correlated noise properties. We also find a weak dependence of the detection efficiency on the position within the field of view. By restricting the Kepler stellar sample to stars with well-behaved correlated noise properties, we can define a set of stars with high detection efficiency for future occurrence-rate calculations.

Keywords: Exoplanet astronomy, Exoplanet detection methods, Exoplanet catalogs
Peas in a Pod? Radius Correlations in Kepler Multiplanet Systems. We address the claim of Weiss et al. that the radii of adjacent planets in Kepler multiplanet systems are correlated. We explore two simple toy models—in the first the radii of the planets are chosen at random from a single universal distribution, and in the second we postulate several types of systems with distinct radius distributions. We show that an apparent correlation between the radii of adjacent planets similar to the one reported by Weiss can arise in both models. In addition the second model fits the radius and signal-to-noise distribution of the observed planets. We also comment on the validity of a commonly used correction that is used to estimate intrinsic planet occurrence rates, based on weighting planets by the inverse of their detectability.

Keywords: Exoplanet systems, Exoplanets
NGC 4869 in the Coma Cluster: Twist, Wrap, Overlap, and Bend. The upgraded Giant Metrewave Radio Telescope (GMRT) has been used to image the head-tail radio galaxy NGC 4869 in the Coma cluster with an angular resolution of 6"26 at 250-500 MHz and 2"18 at the 1050-1450 MHz bands. The archival legacy GMRT data have also been used to image the source with angular resolutions from 4"9 to 21"8 at 610 MHz, 325 MHz, 240 MHz, and 150 MHz. We find that the ∼200 kpc scale radio morphology consists of five distinct regions with the clear presence of a pinch at ≈1'4 (=38.8 kpc) and a ridge at ≈3'4 (=94.2 kpc) from the head. The sharp bend by ∼70° at ∼3'5 (=97 kpc) from the head is possibly due to projection effects. The radio spectra show progressive spectral steepening as a function of distance from the head and there is possibly re-acceleration of the synchrotron electrons and perhaps also magnetic field regeneration in the 6″-208″ (=2.8-96.1 kpc) region of the jet. We report a steep spectrum sheath layer enveloping a flat spectrum spine, hinting at a transverse velocity structure with a fast-moving spine surrounded by a slow-moving sheath layer. We also derive the lifetimes of the radiating electrons and equipartition parameters. A plausible explanation for the characteristic feature, a ridge of emission perpendicular to the direction of tail is the flaring of a straight, collimated radio jet as it crosses a surface brightness edge due to Kelvin-Helmholtz instabilities.

Keywords: Radio jets, Extragalactic radio sources, Coma Cluster, X-ray active galactic nuclei, Active galactic nuclei, Tailed radio galaxies, Spectral index, Intracluster medium, Radio sources
An ATA Search for a Repetition of the Wow Signal. The Allen Telescope Array was used to search for signals with characteristics similar to the "Wow" signal, the best candidate for an extraterrestrial radio signal found during Ohio State University's (OSU's) seven-year 21 cm 10-kHz channel sky survey for signals possibly due to extraterrestrial intelligence. While previous follow-up searches have reported null results, our observations covered a 5 deg2 field of view that extends well beyond the locus of all consistent directions of arrival (DOAs) of the original signal, and covered a 10 MHz bandwidth four times wider than the widest prior follow-up observations, using 12.8 kHz channels approximating OSU's 10 kHz resolution. Approximately 100 hours of data were accumulated, considerably more time than any previous follow-up campaigns. We used interferometric imaging with an angular resolution of approximately 0°07 and automated feature-finding to search for point-like features mimicking a Wow repetition, obtaining single-channel sensitivity of ∼1.2 Jy for one minute averages. This allows identification of the DOA of a very brief repetition, with strong discrimination from radio interference, and eliminates the usual constraint that the signal must persist for long periods of time (around one hour) before the true DOA can be verified (because interfering signals from the horizon sometimes masquerade as coming from the look direction). No point-like features significantly exceeding the noise were found inside the full width at half maximum of the OSU fields of view, although one 26σ point-like feature was detected during one 10 second integration about 1/3° away.

Keywords: Astrobiology
SCExAO/CHARIS Near-infrared Integral Field Spectroscopy of the HD 15115 Debris Disk. We present new, near-infrared (1.1-2.4 μm) high-contrast imaging of the debris disk around HD 15115 with the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled with the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS). The SCExAO/CHARIS resolves the disk down to ρ ∼ 0"2 (rproj ∼ 10 au), a factor of ∼3-5 smaller than previous recent studies. We derive a disk position angle of PA ∼ 279°4-280°5 and an inclination of i ∼ 85°3-86.2°. While recent SPHERE/IRDIS imagery of the system could suggest a significantly misaligned two-ring disk geometry, CHARIS imagery does not reveal conclusive evidence for this hypothesis. Moreover, optimizing models of both one- and two-ring geometries using differential evolution, we find that a single ring having a Hong-like scattering phase function matches the data equally well within the CHARIS field of view (ρ ≲ 1″). The disk's asymmetry, well evidenced at larger separations, is also recovered; the west side of the disk appears, on average, around 0.4 mag brighter across the CHARIS bandpass between 0"25 and 1″. Comparing Space Telescope Imaging Spectrograph (STIS) 50CCD optical photometry (2000-10500 Å) with CHARIS near-infrared photometry, we find a red (STIS/50CCD-CHARIS broadband) color for both sides of the disk throughout the 0"4-1″ region of overlap, in contrast to the blue color reported at similar wavelengths for regions exterior to ∼2″. Further, this color may suggest a smaller minimum grain size than previously estimated at larger separations. Finally, we provide constraints on planetary companions and discuss possible mechanisms for the observed inner disk flux asymmetry and color.

Keywords: Debris disks, Circumstellar disks
The Outburst of the Young Star Gaia19bey. We report photometry and spectroscopy of the outburst of the young stellar object Gaia19bey. We have established the outburst light curve with archival Gaia "G," ATLAS "Orange," Zwicky Transient Facility r-band, and Pan-STARRS "rizy"-filter photometry, showing an outburst of ~4 yr duration, longer than typical EX Lupi objects but shorter than FU Orionis objects. Its pre-outburst spectral energy distribution shows a flat far-infrared spectrum, confirming the early evolutionary state of Gaia19bey and its similarity to other deeply embedded young stars experiencing outbursts. A lower limit to the peak outburst luminosity is ~182 ${L}_{\odot }$ at an assumed distance of 1.4 kpc, the minimum plausible distance. Infrared and optical spectroscopy near maximum light show an emission line spectrum, including H I lines, strong red Ca II emission, other metal emission lines, infrared CO bandhead emission, and a strong infrared continuum. Toward the end of the outburst, the emission lines have all but disappeared and the spectrum has changed into an almost pure continuum spectrum. This indicates a cessation of magnetospheric accretion activity. The near-infrared colors have become redder as Gaia19bey has faded, indicating a cooling of the continuum component. Near the end of the outburst, the only remaining strong emission lines are forbidden shock-excited emission lines. Adaptive optics integral-field spectroscopy shows the H2 1-0 S(1) emission with the morphology of an outflow cavity and the extended emission in the [Fe II] line at 1644 nm with the morphology of an edge-on disk. However, we do not detect any large-scale jet from Gaia19bey.

Keywords: Young stellar objects, Eruptive variable stars, FU Orionis stars