adsabs/SciX_UAT_keywords huggingface dataset:
Two Long-period Giant Planets around Two Giant Stars: HD 112570 and HD 154391

We present the discoveries of two giant plants orbiting the red-giant-branch star HD 112570 and the red-clump star HD 154391, based on the radial-velocity (RV) measurements from the Xinglong station and Okayama Astrophysical Observatory. Spectroscopic and asteroseismic analyses suggest that HD 112570 has a mass of 1.15 ± 0.12 M ☉, a radius of 9.85 ± 0.23 R ☉, a metallicity [Fe/H] of -0.46 ± 0.1, and $\mathrm{log}\,g$ of 2.47 ± 0.1. With the joint analysis of RV and Hipparcos-Gaia astrometry, we obtain a dynamical mass of ${M}_{{\rm{p}}}={3.42}_{-0.84}^{+1.4}\ {M}_{\mathrm{Jup}}$ , a period of $P={2615}_{-77}^{+85}$ days, and a moderate eccentricity of $e={0.20}_{-0.14}^{+0.16}$ for the Jovian planet HD 112570 b. For HD 154391, it has a mass of 2.07 ± 0.03 M ☉, a radius of 8.56 ± 0.05 R ☉, a metallicity [Fe/H] of 0.07 ± 0.1, and $\mathrm{log}\,g$ of 2.86 ± 0.1. The super-Jupiter HD 154391 b has a mass of ${M}_{{\rm{p}}}={9.1}_{-1.9}^{+2.8}\ {M}_{\mathrm{Jup}}$ , a period of $P={5163}_{-57}^{+60}$ days, and an eccentricity of $e={0.20}_{-0.04}^{+0.04}$ . We found that HD 154391 b has one of the longest orbital periods among those ever discovered orbiting evolved stars, which may provide a valuable case in our understanding of planetary formation at wider orbits. Moreover, while a mass gap at 4 M Jup seems to be present in the population of giant stars, there appear to be no significant differences in the distribution of metallicity among giant planets with masses above or below this threshold. Finally, the origin of the abnormal accumulation near 2 au for planets around large evolved stars (R ⋆ > 21 R ☉), remains unclear.

Keywords: exoplanet astronomy; evolved stars; radial velocity; planet formation
Orbits and Masses of the Small Satellites of Pluto

We present a new orbit and mass solution for the four small satellites of Pluto: Styx, Nix, Kerberos, and Hydra. We have reanalyzed all available observations of the Pluto system obtained by the Hubble Space Telescope from 2005 to 2019 with the ACS, WFPC2, and WFC3 instruments, as well as the New Horizons LORRI images taken on approach to Pluto in 2015. We have used this high-precision astrometry to produce updated orbits and mass estimates with uncertainties for all four of the small satellites. We find that the masses of Nix and Hydra are smaller than previously published estimates, with a dynamical mass of (1.8 ± 0.4) × 10-3 km3 s-2 ((2.7 ± 0.6) × 1016 kg) for Nix and (2.0 ± 0.2) × 10-3 km3 s-2 ((3.0 ± 0.3) × 1016 kg) for Hydra. These masses are 60% and 63% of the mean estimates by Brozovic et al., respectively, although still consistent with their 1σ uncertainties, and correspond to densities of 1.0 ± 0.2 g cm-3 for Nix and 1.2 ± 0.2 g cm-3 for Hydra given the moon volume estimates from Porter et al. Although these densities are consistent with a range of ice-rock compositions, depending on the unknown bulk porosity in the moon interiors, the moons' high albedos and predominantly icy surfaces are most easily explained if their interiors are ice-rich. The tiny masses of Kerberos and Sytx remain very poorly constrained; we find 1σ upper limits for dynamical mass of 3 × 10-5 km3 s-2 (5 × 1014 kg) for Styx and 5 ×10-5 km3 s-2 (8 × 1014 kg) for Kerberos, consistent with densities of <2.1 g cm-3 for both bodies.

Keywords: pluto; natural satellite dynamics; plutonian satellites
DUVET: Spatially Resolved Observations of Star Formation Regulation via Galactic Outflows in a Starbursting Disk Galaxy

We compare 500 pc scale, resolved observations of ionized and molecular gas for the z ~ 0.02 starbursting disk galaxy IRAS08339+6517, using measurements from KCWI and NOEMA. We explore the relationship of the star-formation-driven ionized gas outflows with colocated galaxy properties. We find a roughly linear relationship between the outflow mass flux ( ${\dot{{\rm{\Sigma }}}}_{\mathrm{out}}$ ) and star formation rate surface density (ΣSFR), ${\dot{{\rm{\Sigma }}}}_{\mathrm{out}}\propto {{\rm{\Sigma }}}_{\mathrm{SFR}}^{1.06\pm 0.10}$ , and a strong correlation between ${\dot{{\rm{\Sigma }}}}_{\mathrm{out}}$ and the gas depletion time, such that ${\dot{{\rm{\Sigma }}}}_{\mathrm{out}}\propto {t}_{\mathrm{dep}}^{-1.1\pm 0.06}$ . Moreover, we find these outflows are so-called breakout outflows, according to the relationship between the gas fraction and disk kinematics. Assuming that ionized outflow mass scales with total outflow mass, our observations suggest that the regions of highest ΣSFR in IRAS08 are removing more gas via the outflow than through the conversion of gas into stars. Our results are consistent with a picture in which the outflow limits the ability of a region of a disk to maintain short depletion times. Our results underline the need for resolved observations of outflows in more galaxies.

Keywords: galaxy winds; galaxy evolution; starburst galaxies; galaxies
PINT: A Modern Software Package for Pulsar Timing

Over the past few decades, the measurement precision of some pulsar timing experiments has advanced from ∼10 μs to ∼10 ns, revealing many subtle phenomena. Such high precision demands both careful data handling and sophisticated timing models to avoid systematic error. To achieve these goals, we present PINT (PINT Is Not TEMPO3), a high-precision Python pulsar timing data analysis package, which is hosted on GitHub and available on the Python Package Index (PyPI) as pint-pulsar. PINT is well tested, validated, object oriented, and modular, enabling interactive data analysis and providing an extensible and flexible development platform for timing applications. It utilizes well-debugged public Python packages (e.g., the NUMPY and ASTROPY libraries) and modern software development schemes (e.g., version control and efficient development with git and GitHub) and a continually expanding test suite for improved reliability, accuracy, and reproducibility. PINT is developed and implemented without referring to, copying, or transcribing the code from other traditional pulsar timing software packages (e.g., TEMPO/TEMPO2) and therefore provides a robust tool for cross-checking timing analyses and simulating pulse arrival times. In this paper, we describe the design, use, and validation of PINT, and we compare timing results between it and TEMPO and TEMPO2.

Keywords: millisecond pulsars; radio pulsars; pulsar timing method; pulsars; astronomy software
Origins of the Long-term Variability of the Near-infrared Emission of the Black Hole X-Ray Binary GRS 1915+105 in the X-Ray Low Luminous State

Since 2018 July, the black hole X-ray binary GRS 1915+105 has been in an X-ray low luminous state (XLLS), which is the faintest period ever observed in a soft X-ray band. We present here the results of near-infrared (NIR) observations from 2019 April-December in the XLLS using HONIR attached to the Kanata telescope, together with radio data obtained by the Yamaguchi Interferometer and archival X-ray data. We found the historical NIR brightening in the XLLS. For several tens of days in the XLLS, NIR flux showed a positive correlation with radio flux and negative correlation with X-ray flux. This result suggests that at least a jet contributes to the NIR bands in the NIR-bright XLLS period. An accretion disk is not likely a candidate for the NIR emission because of the decrease of X-ray flux. In contrast to the NIR band, there was no historical radio brightening in the XLLS. This implies that the NIR emission in the NIR-bright period cannot be explained by the jet alone. The X-ray obscuration suggested by X-ray data is another possible candidate for the nonjet emission component in the NIR band.

Keywords: low-mass x-ray binary stars; accretion; near infrared astronomy; black hole physics
ALMA Lensing Cluster Survey: Bright [C II] 158 μm Lines from a Multiply Imaged Sub-L⋆ Galaxy at z = 6.0719

We present bright [C II] 158 μm line detections from a strongly magnified and multiply imaged (μ ∼ 20-160) sub-L* ( ${M}_{\mathrm{UV}}=-{19.75}_{-0.44}^{+0.55}$ ) Lyman-break galaxy (LBG) at z = 6.0719 ± 0.0004, drawn from the ALMA Lensing Cluster Survey (ALCS). Emission lines are identified at 268.7 GHz at ≥8σ exactly at the positions of two multiple images of the LBG, behind the massive galaxy cluster RXCJ0600-2007. Our lens models, updated with the latest spectroscopy from VLT/MUSE, indicate that a sub region of the LBG crosses the caustic, and is lensed into a long (∼6″) arc with a local magnification of μ ∼ 160, for which the [C II] line is also significantly detected. The source plane reconstruction resolves the interstellar medium (ISM) structure, showing that the [C II] line is co-spatial with the rest-frame UV continuum at a scale of ∼300 pc. The [C II] line properties suggest that the LBG is a rotation-dominated system, whose velocity gradient explains a slight difference in redshifts between the whole LBG and its sub-region. The star formation rate (SFR)-L[CII] relations, for whole and sub-regions of the LBG, are consistent with those of local galaxies. We evaluate the lower limit of the faint-end of the [C II] luminosity function at z = 6, finding it to be consistent with predictions from semi-analytical models and from the local SFR-L[CII] relation with a SFR function at z = 6. These results imply that the local SFR-L[CII] relation is universal for a wide range of scales, including the spatially resolved ISM, the whole region of the galaxy, and the cosmic scale, even in the epoch of reionization.

Keywords: galaxy evolution; galaxy formation; high-redshift galaxies; interstellar medium; strong gravitational lensing; galaxy kinematics; luminosity function
Photometric Completeness Modelled with Neural Networks

In almost any study involving optical/near-infrared photometry, understanding the completeness of detection and recovery is an essential part of the work. The recovery fraction is, in general, a function of several variables including magnitude, color, background sky noise, and crowding. We explore how completeness can be modeled, with the use of artificial-star tests, in a way that includes all of these parameters simultaneously within a neural network (NN) framework. The method is able to manage common issues including asymmetric completeness functions and the bilinear dependence of the detection limit on color index. We test the method with two sample Hubble Space Telescope data sets: the first involves photometry of the star cluster population around the giant Perseus galaxy NGC 1275, and the second involves the halo-star population in the nearby elliptical galaxy NGC 3377. The NN-based method achieves a classification accuracy of > 94% and produces results entirely consistent with more traditional techniques for determining completeness. Additional advantages of the method are that none of the issues arising from the binning of the data are present and that a recovery probability can be assigned to every individual star in real photometry. Our data, models, and code (called COINTOSS) can be found online on Zenodo at the following link: https://doi.org/10.5281/zenodo.8306488.

Keywords: stellar photometry; neural networks; photometry; direct imaging; statistical parallax; astrostatistics techniques
CLASSY V: The Impact of Aperture Effects on the Inferred Nebular Properties of Local Star-forming Galaxies

Strong nebular emission lines are an important diagnostic tool for tracing the evolution of star-forming galaxies across cosmic time. However, different observational setups can affect these lines, and the derivation of the physical nebular properties. We analyze 12 local star-forming galaxies from the COS Legacy Spectroscopy SurveY (CLASSY) to assess the impact of using different aperture combinations on the determination of the physical conditions and gas-phase metallicity. We compare optical spectra observed with the Sloan Digital Sky Survey Data Release aperture, which has a 3″ diameter similar to COS, IFU, and long-slit spectra, including new LBT/MODS observations of five CLASSY galaxies. We calculate the reddening, electron densities and temperatures, metallicities, star formation rates, and equivalent widths (EWs). We find that measurements of the electron densities and temperatures, and metallicity remained roughly constant with aperture size, indicating that the gas conditions are relatively uniform for this sample. However, using IFU observations of three galaxies, we find that the E(B - V) values derived from the Balmer ratios decrease (by up to 53%) with increasing aperture size. The values change most significantly in the center of the galaxies, and level out near the COS aperture diameter of 2.″5. We examine the relative contributions from the gas and stars using the Hα and [O III] λ5007 EWs as a function of aperture light fraction, but find little to no variations within a given galaxy. These results imply that the optical spectra provide nebular properties appropriate for the far-UV CLASSY spectra, even when narrow 1.″0 long-slit observations are used.

Keywords: emission line galaxies; optical astronomy; galaxy abundances; dwarf galaxies
Molecular Outflows in z > 6 Unobscured QSO Hosts Driven by Star Formation

Feedback and outflows in galaxies that are associated with a quasar phase are expected to be pivotal in quenching the most massive galaxies. However, observations targeting the molecular outflow phase, which dominates both the mass and momentum and removes the immediate fuel for star formation, are limited in high-z QSO hosts. Massive quiescent galaxies found at z ~ 4 are predicted to have quenched star formation already by z ~ 5 and undergone their most intense growth at z > 6. Here, we present two Atacama Large Millimeter/submillimeter Array (ALMA) detections of molecular outflows, traced by blueshifted absorption of the OH 119 μm doublet, from a sample of three z > 6 infrared luminous QSO hosts: J2310+1855 and P183+05. OH 119 μm is also detected in emission from P183+05, and tentatively in the third source: P036+03. Using similar assumptions as for high-z dusty star-forming galaxy outflows, we find that our QSOs drive molecular outflows with comparable mass outflow rates, which are comparably energetic except for J2310+1855's significantly lower outflow energy flux. We do not find evidence, nor require additional input from the central active galactic nucleus (AGN) to drive the molecular outflow in J2310+1855, but we cannot rule out an AGN contribution in P183+05 if a significant AGN contribution to L FIR is assumed and/or if the outflow covering fraction is high (≥53%), which evidence from the literature suggests is unlikely in these sources. Differences observed in the blueshifted absorption spectral properties may instead be caused by the QSO hosts' more compact dust continuums, limiting observations to lower altitude and more central regions of the outflow.

Keywords: high-redshift galaxies; galactic winds; agn host galaxies; quasars; stellar feedback
Photometric and Spectroscopic Observations of GRB 190106A: Emission from Reverse and Forward Shocks with Late-time Energy Injection

Early optical observations of gamma-ray bursts can significantly contribute to the study of the central engine and physical processes therein. However, of the thousands observed so far, only a few have data at optical wavelengths in the first minutes after the onset of the prompt emission. Here we report on GRB 190106A, whose afterglow was observed in optical bands just 36 s after the Swift/BAT trigger, i.e., during the prompt emission phase. The early optical afterglow exhibits a bimodal structure followed by a normal decay, with a faster decay after ~T 0 + 1 day. We present optical photometric and spectroscopic observations of GRB 190106A. We derive the redshift via metal absorption lines from Xinglong 2.16 m/BFOSC spectroscopic observations. From the BFOSC spectrum, we measure z = 1.861 ± 0.002. The double-peak optical light curve is a significant feature predicted by the reverse-forward external-shock model. The shallow decay followed by a normal decay in both the X-ray and optical light curves is well explained with the standard forward-shock model with late-time energy injection. Therefore, GRB 190106A offers a case study for GRB emission from both reverse and forward shocks.

Keywords: gamma-ray bursts
The Star Formation History of a Post-starburst Galaxy Determined from Its Cluster Population

The recent star formation histories (SFHs) of post-starburst galaxies have been determined almost exclusively from detailed modeling of their composite starlight. This has provided important but limited information on the number, strength, and duration of bursts of star formation. In this work, we present a direct and independent measure of the recent SFH of the post-starburst galaxy S12 (plate-mjd-fiber for SDSS 623-52051-207; designated EAS12 in Smercina et al.) from its star cluster population. We detect clusters from high-resolution, UBR optical images taken with the Hubble Space Telescope and compare their luminosities and colors with stellar population models to estimate the ages and masses of the clusters. No clusters younger than ~70 Myr are found, indicating star formation shut off at this time. Clusters formed ~120 Myr ago reach masses up to a ~few × 107 M⊙, several times higher than similar-age counterparts formed in actively merging galaxies like the Antennae and NGC 3256. We develop a new calibration based on known properties for eight nearby galaxies to estimate the star formation rate (SFR) of a galaxy from the mass of the most massive cluster, Mmax. The cluster population indicates that S12 experienced an extremely intense but short-lived burst ~120 Myr ago, with an estimated peak of ${500}_{-250}^{+500}\,{M}_{\odot }\,{{\rm{yr}}}^{-1}$ and duration of 50 ± 25 Myr, one of the highest SFRs estimated for any galaxy in the modern universe. The cluster population also allows us to fill in more of the backstory of S12. Prior to the recent, intense burst, S12 was forming stars at a moderate rate of ~3-5 M⊙ yr-1, typical of spiral galaxies, but the system experienced an earlier burst at some point, approximately 1-3 Gyr ago. While fairly uncertain, we estimate that the SFR during this earlier burst was ~20-30 M⊙ yr-1, similar to the current SFR in the Antennae and NGC 3256.

Keywords: galaxy formation
Evaluating the Plausible Range of N2O Biosignatures on Exo-Earths: An Integrated Biogeochemical, Photochemical, and Spectral Modeling Approach

Nitrous oxide (N2O)-a product of microbial nitrogen metabolism-is a compelling exoplanet biosignature gas with distinctive spectral features in the near- and mid-infrared, and only minor abiotic sources on Earth. Previous investigations of N2O as a biosignature have examined scenarios using Earthlike N2O mixing ratios or surface fluxes, or those inferred from Earth's geologic record. However, biological fluxes of N2O could be substantially higher, due to a lack of metal catalysts or if the last step of the denitrification metabolism that yields N2 from N2O had never evolved. Here, we use a global biogeochemical model coupled with photochemical and spectral models to systematically quantify the limits of plausible N2O abundances and spectral detectability for Earth analogs orbiting main-sequence (FGKM) stars. We examine N2O buildup over a range of oxygen conditions (1%-100% present atmospheric level) and N2O fluxes (0.01-100 teramole per year; Tmol = 1012 mole) that are compatible with Earth's history. We find that N2O fluxes of 10 [100] Tmol yr-1 would lead to maximum N2O abundances of ~5 [50] ppm for Earth-Sun analogs, 90 [1600] ppm for Earths around late K dwarfs, and 30 [300] ppm for an Earthlike TRAPPIST-1e. We simulate emission and transmission spectra for intermediate and maximum N2O concentrations that are relevant to current and future space-based telescopes. We calculate the detectability of N2O spectral features for high-flux scenarios for TRAPPIST-1e with JWST. We review potential false positives, including chemodenitrification and abiotic production via stellar activity, and identify key spectral and contextual discriminants to confirm or refute the biogenicity of the observed N2O.

Keywords: astrobiology; exoplanet atmospheres; exoplanets; habitable planets; nitrous oxide; biosignatures
A Unified Model for Bipolar Outflows from Young Stars: Kinematic Signatures of Jets, Winds, and Their Magnetic Interplay with the Ambient Toroids

Kinematic signatures of the jet, winds, multicavities, and episodic shells arising in the unified model of bipolar outflows developed in Shang et al. (Paper I), in which an outflow forms by radially directed, wide-angle toroidally magnetized winds interacting with magnetized isothermal toroids, are extracted in the form of position-velocity diagrams. Elongated outflow lobes, driven by magnetized winds and their interplay with the environment, are dominated by extended bubble structures with mixing layers beyond the conventional thin-shell models. The axial cylindrically stratified density jet carries a broad profile near the base, across the projected velocity of the wide-angle wind, and narrows down along the axis with the collimated flow. The reverse shock encloses the magnetized free wind, forms an innermost cavity, and deflects the flow pattern. Shear, Kelvin-Helmholtz instabilities, and pseudopulses add fine and distinctive features between the jet-shell components, and the fluctuating jet velocities. The broad webbed velocity features connect the extremely high and the low velocities across the multicavities, mimicking nested outflowing slower-wind components. Rings and ovals in the perpendicular cuts trace multicavities at different heights, and the compressed ambient gap regions enrich the low-velocity features with protruding spikes. Our kinematic signatures capture the observed systematics of the high-, intermediate-, and low-velocity components from Class 0 to II jet-outflow systems in molecular and atomic lines. The nested shells observed in HH 212, HH 30, and DG Tau B are naturally explained. Outflows as bubbles are ubiquitous and form an inevitable integrative outcome of the interaction between wind and ambient media.

Keywords: stellar jets; stellar winds; stellar wind bubbles; collapsing clouds; young stellar objects; protostars; star formation; magnetohydrodynamical simulations; interstellar line emission
Elusive Iron: Detection of the FeC Radical (X 3Δ i ) in the Envelope of IRC+10216

A new interstellar molecule, FeC (X 3Δ i ), has been identified in the circumstellar envelope of the carbon-rich asymptotic giant branch star IRC+10216. FeC is the second iron-bearing species conclusively observed in the interstellar medium, in addition to FeCN, also found in IRC+10216. The J = 4 → 3, 5 → 4, and 6 → 5 rotational transitions of this free radical near 160, 201, and 241 GHz, respectively, were detected in the lowest spin-orbit ladder, Ω = 3, using the Submillimeter Telescope of the Arizona Radio Observatory (ARO) for the 1 mm lines and the ARO 12 m at 2 mm. Because the ground state of FeC is inverted, these transitions are the lowest energy lines. The detected features exhibit slight U shapes with LSR velocities near V LSR ≈ -26 km s-1 and linewidths of ΔV 1/2 ≈ 30 km s-1, line parameters characteristic of IRC+10216. Radiative transfer modeling of FeC suggests that the molecule has a shell distribution with peak radius near 300 R * (~6″) extending out to ~500 R * (~10″) and a fractional abundance, relative to H2, of f ~ 6 × 10-11. The previous FeCN spectra were also modeled, yielding an abundance of f ~ 8 × 10-11 in a larger shell situated near 800 R *. These distributions suggest that FeC may be the precursor species for FeCN. Unlike cyanides and carbon-chain molecules, diatomic carbides with a metallic element are rare in IRC+10216, with FeC being the first such detection.

Keywords: astrochemistry; evolved stars; circumstellar envelopes; interstellar molecules; radio astronomy; asymptotic giant branch stars