adsabs/SciX_UAT_keywords huggingface dataset:
Breaking Degeneracies in Formation Histories by Measuring Refractory Content in Gas Giants

Relating planet formation to atmospheric composition has been a long-standing goal of the planetary science community. So far, most modeling studies have focused on predicting the enrichment of heavy elements and the C/O ratio in giant planet atmospheres. Although this framework provides useful constraints on the potential formation locations of gas giant exoplanets, carbon and oxygen measurements alone are not enough to determine where a given gas giant planet originated. Here, we show that characterizing the abundances of refractory elements (e.g., silicon and iron) can break these degeneracies. Refractory elements are present in the solid phase throughout most of the disk, and their atmospheric abundances therefore reflect the solid-to-gas accretion ratio during formation. We introduce a new framework that parameterizes the atmospheric abundances of gas giant exoplanets in the form of three ratios: Si/H, O/Si, and C/Si. Si/H traces the solid-to-gas accretion ratio of a planet and is loosely equivalent to earlier notions of "metallicity." For O/Si and C/Si, we present a global picture of their variation with distance and time based on what we know from the solar system meteorites and an updated understanding of the variations of thermal processing within protoplanetary disks. We show that ultrahot Jupiters are ideal targets for atmospheric characterization studies using this framework as we can measure the abundances of refractories, oxygen, and carbon in the gas phase. Finally, we propose that hot Jupiters with silicate clouds and low water abundances might have accreted their envelopes between the soot line and the water snow line.

Keywords: exoplanet atmospheres; planet formation; hot jupiters; atmospheric composition
Detecting Baryon Acoustic Oscillations with Third-generation Gravitational Wave Observatories

We explore the possibility of detecting baryon acoustic oscillations (BAO) solely from gravitational wave (GW) observations of binary neutron star mergers with third-generation (3G) GW detectors such as the Cosmic Explorer and the Einstein Telescope. These measurements would provide a new independent probe of cosmology. The detection of the BAO peak with current-generation GW detectors (solely from GW observations) is not possible because i) unlike galaxies, the GW mergers are poorly localized, and ii) there are not enough merger events to probe the BAO length scale. With the 3G GW detector network, it is possible to observe $\sim { \mathcal O }(1000)$ binary neutron star mergers per year that are localized well within one square degree in the sky for redshift z ≤ 0.3. We show that 3G observatories will enable precision measurements of the BAO feature in the large-scale two-point correlation function; the effect of BAO can be independently detected at different redshifts, with a log-evidence ratio of ~23, 17, or 3, favoring a model with a BAO peak at redshift of 0.2, 0.25, or 0.3, respectively, using a redshift bin corresponding to a shell of thickness 150h -1 Mpc.

Keywords: gravitational wave astronomy; gravitational wave detectors; baryon acoustic oscillations; large-scale structure of the universe; cosmology; gravitational wave sources; gravitational waves
Extinction Values toward Embedded Planets in Protoplanetary Disks Estimated from Hydrodynamic Simulations

Upcoming new coronographs with deeper contrast limits, together with planned and current high-contrast imaging campaigns, will push the detectability limit of protoplanets. These planet-hunting campaigns present a new opportunity to characterize protoplanets and their surrounding environments. However, there are clear uncertainties as to what the extinction levels are at different regions of protoplanetary disks, which will impede our ability to characterize young planets. A correct understanding of the expected extinction, together with multiple photometric observations, will lead to constraints on the extinction levels, dust growth, disk evolution, and protoplanetary accretion rates. In this work, we used hydrodynamic simulations and protoplanetary disk observational constraints obtained from both dust and gas emission to explore the expected extinction maps for continuum filters associated with strong hydrogen lines as tracers of accretion and key broadband photometric filters. We provide a scaling relationship for the extinction as a function of planetary separation and disk mass for three different gas giant masses. We also report values for a subset of disks of interest targeted by multiple imaging campaigns. The described values will be useful for the optimal design of future planet-hunting surveys and for giving context to nondetections in protoplanetary disks and the observed fluxes of point sources along with the birth conditions of protoplanets.

Keywords: protoplanetary disks; extinction; hydrodynamical simulations; exoplanet detection methods
The GBT Diffuse Ionized Gas Survey (GDIGS): Discrete Sources

The Green Bank Telescope Diffuse Ionized Gas Survey (GDIGS) traces ionized gas in the Galactic midplane by observing radio recombination line (RRL) emission from 4 to 8 GHz. The nominal survey zone is 32.°3 > ℓ > ‑5°, ∣ b ∣ < 0.°5. Here, we analyze GDIGS Hnα ionized gas emission toward discrete sources. Using GDIGS data, we identify the velocity of 35 H II regions that have multiple detected RRL velocity components. We identify and characterize RRL emission from 88 H II regions that previously lacked measured ionized gas velocities. We also identify and characterize RRL emission from eight locations that appear to be previously unidentified H II regions and 30 locations of RRL emission that do not appear to be H II regions based on their lack of mid-infrared emission. This latter group may be a compact component of the Galactic Diffuse Ionized Gas. There are an additional 10 discrete sources that have anomalously high RRL velocities for their locations in the Galactic plane. We compare these objects' RRL data to 13CO, H I, and mid-infrared data, and find that these sources do not have the expected 24 μm emission characteristic of H II regions. Based on this comparison we do not think these objects are H II regions, but we are unable to classify them as a known type of object.

Keywords: warm ionized medium; interstellar plasma; h ii regions; interstellar line emission; interstellar medium
The Halo Bias inside Cosmic Voids

The bias of dark matter halos and galaxies is a crucial quantity in many cosmological analyses. In this work, using large cosmological simulations, we explore the halo mass function and halo bias within cosmic voids. For the first time to date, we show that they are scale dependent along the void profile, and provide a predictive theoretical model of both the halo mass function and halo bias inside voids, recovering for the latter a 1% accuracy against simulated data. These findings may help shed light on the dynamics of halo formation within voids and improve the analysis of several void statistics from ongoing and upcoming galaxy surveys.

Keywords: voids; large-scale structure of the universe; galaxy dark matter halos; cosmology
Drift Rates of Narrowband Signals in Long-term SETI Observations for Exoplanets

The Doppler shift of a radio signal is caused by the relative motion between the transmitter and receiver. The change in frequency of the signal over time is called the drift rate. In the studies of radio search for extraterrestrial intelligence (SETI), extraterrestrial narrowband signals are expected to appear "chirped" since both the exoplanet and Earth are moving. Such planet rotation and orbital revolution around the central star can cause a nonzero drift rate. Other relative motions between the transmitter and receiver, such as the gravitational redshift and galactic potential, are negligible. In this paper, we mainly consider the common cases in which the drift rate is contributed by the rotations and orbits of Earth and the exoplanet in the celestial mechanics perspective, and we briefly discuss other cases different from the Earth-exoplanet one. We can obtain the expected pseudosinusoidal drifting result with long-term observations and shorter orbital periods of exoplanets. Exoplanets with higher orbital eccentricities can cause asymmetric drifting. The expected result should be intermittent pseudosinusoidal curves in long-term observations. The characteristics of pseudosinusoidal curves, as another new criterion for extraterrestrial signals, can be applied to long-term SETI reobservations in future research.

Keywords: search for extraterrestrial intelligence; celestial mechanics
The Typical Massive Quiescent Galaxy at z ∼ 3 is a Post-starburst

We have obtained spectroscopic confirmation with Hubble Space Telescope WFC3/G141 of a first sizeable sample of nine quiescent galaxies at 2.4 < z < 3.3. Their average near-UV/optical rest-frame spectrum is characterized by low attenuation (AV ∼ 0.6 mag) and a strong Balmer break, larger than the 4000 Å break, corresponding to a fairly young age of ∼300 Myr. This formally classifies a substantial fraction of classically selected quiescent galaxies at z ∼ 3 as post-starbursts, marking their convergence to the quenching epoch. The rapid spectral evolution with respect to z ∼ 1.5 quiescent galaxies is not matched by an increase of residual star formation, as judged from the weak detection of [O II]λ3727 emission, pointing to a flattening of the steep increase in gas fractions previously seen from z ∼ 0 to 1.8. However, radio 3 GHz stacked emission implies either much stronger dust-obscured star formation or substantial further evolution in radio-mode AGN activity with respect to z ∼ 1.5.

Keywords: galaxy evolution; galaxy quenching; quenched galaxies
An Ultradeep Multiband Very Large Array Survey of the Faint Radio Sky (COSMOS-XS): New Constraints on the Optically Dark Population

Attempts to trace star formation with rest-frame UV/optical observations at redshifts z > 2 are affected by the presence of potentially substantial, yet uncertain, dust attenuation. Recent studies have demonstrated the existence of a population of galaxies that are virtually invisible in the observed optical/near-infrared (NIR) due to dust obscuration, but which could contribute substantially to the star formation history at 2 < z < 6. Here, we make use of ultradeep 3 GHz Karl G. Jansky Very Large Array observations from the COSMOS-XS survey to investigate the contribution 20of radio-selected "optically dark" galaxies (undetected to a depth of K S ~ 25.9 mag) to the cosmic star formation rate density (SFRD). We identify 19 such "optically dark" sources and utilize recent deblended far-infrared photometry to determine photometric redshifts based on IR and radio information for 11 of them. Through stacking, we infer that the remaining eight sources reside predominantly at high redshift (z > 4). Therefore, we conservatively assume these sources lie between z = 2 and z = 5. We derive the radio luminosity function (LF) for the sample with and without "optically dark" sources by fixing the faint and bright end shape of the radio LF to the local values and allowing for luminosity evolution. By integrating both LFs, we estimate the contribution of the "optically dark" galaxies to the radio SFRD to be $\sim {15}_{-7}^{+7} \% $ at z ~ 5. This is consistent with constraints from NIR-dark and UV-dark sources, while being in disagreement with some estimates using H-dropouts. This result implies that "optically dark" sources play a nonnegligible role at high redshift.

Keywords: galaxy evolution; star formation; radio continuum emission
The Black Hole Spin in GRS 1915+105, Revisited

We estimate the black hole spin parameter in GRS 1915+105 using the continuum-fitting method with revised mass and inclination constraints based on the very long baseline interferometric parallax measurement of the distance to this source. We fit Rossi X-ray Timing Explorer observations selected to be accretion-disk-dominated spectral states as described in McClintock et al. (2006) and Middleton et al. (2006), which previously gave discrepant spin estimates with this method. We find that, using the new system parameters, the spin in both data sets increased, providing a best-fit spin of a* = 0.86 for the Middleton et al. data and a poor fit for the McClintock et al. data set, which becomes pegged at the BHSPEC model limit of a* = 0.99. We explore the impact of the uncertainties in the system parameters, showing that the best-fit spin ranges from a* = 0.4 to 0.99 for the Middleton et al. data set and allows reasonable fits to the McClintock et al. data set with near-maximal spin for system distances greater than ~10 kpc. We discuss the uncertainties and implications of these estimates.

Keywords: x-ray binary stars; black hole physics; stellar accretion disks; rotating black holes
Chemical Abundances of a Sample of Oxygen-dominated Galaxies

We spectroscopically analyzed a sample of 85 Sloan Digital Sky Survey compact, oxygen-dominated galaxies located at redshift z ~ 0.001-0.350, selected because of their large equivalent width of [O III]λ5007 (larger than 200 Å). These galaxies might be considered as extreme emission-line galaxies due to their strong [O III]λ5007 emission line. We detected high-ionization lines, even those related to the presence of Wolf-Rayet stars, in almost all the galaxies studied. We obtained physical properties (electron density and temperature) as well as chemical abundances by using the direct method based on the electron temperature. In this analysis, we obtained three different measurements of T(high): the usual one, T([O III]), but also that of T([S III]) and T([Ar III]) for five and three of the galaxies, respectively. Further, we established a new calibration for T([S III]). We determined oxygen, nitrogen, sulfur, neon, argon, iron, and chlorine abundances when possible, and we compared to the results of other late-type, low-metallicity galaxies, such as blue compact dwarfs, Ims, and green peas. From such a detailed study, we can conclude that the majority of the galaxies in this sample have similar metallicities to the SMC (about $12+\mathrm{log}({\rm{O}}/{\rm{H}}$ ) ≈ 8 dex), and that only 12% of the galaxies are extremely metal-poor, with abundances lower than 7.7 dex. Also, a comparison with some chemical evolution models as well as a brief discussion on the chemical evolution with time is considered.

Keywords: metallicity; chemical abundances; abundance ratios; spectroscopy
Joint Radial Velocity and Direct Imaging Planet Yield Calculations. I. Self-consistent Planet Populations

Planet yield calculations may be used to inform the target selection strategy and science operations of space observatories. Forthcoming and proposed NASA missions, such as the Wide-Field Infrared Survey Telescope, the Habitable Exoplanet Imaging Mission, and the Large UV/Optical/IR Surveyor, are expected to be equipped with sensitive coronagraphs and/or starshades. We are developing a suite of numerical simulations to quantify the extent to which ground-based radial velocity (RV) surveys could boost the detection efficiency of direct imaging missions. In this paper, we discuss the first step in the process of estimating planet yields: generating synthetic planetary systems consistent with observed occurrence rates from multiple detection methods. In an attempt to self-consistently populate stars with orbiting planets, it is found that naive extrapolation of occurrence rates (mass, semimajor axis) results in an unrealistically large number density of Neptune-mass planets beyond the ice line (a ≳ 5 au), causing dynamic interactions that would destabilize orbits. We impose a stability criterion for multiplanet systems based on mutual Hill radii separation. Considering the influence of compact configurations containing Jovian-mass and Neptune-mass planets results in a marked suppression in the number of terrestrial planets that can exist at large radii. This result has a pronounced impact on planet yield calculations particularly in regions accessible to high-contrast imaging and microlensing. The dynamically compact configurations and occurrence rates that we develop may be incorporated as input into joint RV and direct imaging yield calculations to place meaningful limits on the number of detectable planets with future missions.

Keywords: radial velocity; exoplanet detection methods; direct imaging; astronomical simulations
Early Results from GLASS-JWST. II. NIRCam Extragalactic Imaging and Photometric Catalog

We present the reduced images and multiwavelength catalog of the first JWST NIRCam extragalactic observations from the GLASS Early Release Science Program, obtained as coordinated parallels of the NIRISS observations of the Abell 2744 cluster. Images in seven bands (F090W, F115W, F150W, F200W, F277W, F356W, and F444W) have been reduced using an augmented version of the official JWST pipeline; we discuss the procedures adopted to remove or mitigate defects in the raw images. We obtain a multiband catalog by means of forced aperture photometry on point-spread function (PSF)-matched images at the position of F444W-detected sources. The catalog is intended to enable early scientific investigations, and it is optimized for faint galaxies; it contains 6368 sources, with limiting magnitude 29.7 at 5σ in F444W. We release both images and catalog in order to allow the community to become familiar with the JWST NIRCam data and evaluate their merit and limitations given the current level of knowledge of the instrument.

Keywords: surveys; photometry; galaxies; astronomy image processing
On the Impact of Random Residual Calibration Error on the Gibbs ILC CMB Estimates over Large Angular Scales

Residual errors in calibration coefficients corresponding to observed cosmic microwave background (CMB) maps are an important issue when estimating a pure CMB signal. These errors in the input-foreground-contaminated CMB maps, if not properly taken into account in a component separation method, may lead to bias in the cleaned CMB map and estimated CMB angular power spectrum. But the inability to exactly determine the calibration coefficients corresponding to each observed CMB map from a multifrequency CMB experiment makes it very difficult to incorporate their exact and actual values during the component separation method. Hence, the effect of any random and residual calibration error in the cleaned CMB map and its angular power spectrum of a component separation problem can only be understood by performing detailed Monte Carlo simulations. In this paper, we investigate the impact of using input-observed CMB maps with random calibration errors on the posterior density of a cleaned CMB map and theoretical CMB angular power spectrum over large angular scales of the sky following the Gibbs Internal-Linear-Combination (ILC) method. By performing detailed Monte Carlo simulations of WMAP and Planck temperature anisotropy observations, including their estimate on calibration errors, we show that the best-fit map corresponding to the posterior maximum is minimally biased in the Gibbs ILC method by a CMB normalization bias and residual foreground bias. The residual calibration-induced error in the best-fit power spectrum causes an overall 6% increase of the net error when added in quadrature with the cosmic-variance-induced error.

Keywords: cosmic microwave background radiation; gibbs sampler; posterior distribution
Investigating 16 Open Clusters in the Kepler/K2-Gaia DR3 Field. I. Membership, Binary Systems, and Rotation

Using data from Gaia Data Release 3 and Kepler/K2, we present a catalog of 16 open clusters with ages ranging from 4-4000 Myr that provides detailed information on membership, binary systems, and rotation. We assess the memberships in 5D phase space, and estimate the basic parameters of each cluster. Among the 20,160 members, there are 4381 stars identified as binary candidates and 49 stars identified as blue straggler stars. The fraction of binaries varies in each cluster, and the range is between 9% and 44%. We obtain the rotation periods of 5467 members, of which 4304 are determined in this work. To establish a benchmark for the rotation-age-color relation, we construct color-period diagrams. We find that the rotational features of binaries are similar to that of single stars, while the features for binaries are more scattered in the rotation period. Moreover, the morphology of the color-period relationship is already established for Upper Scorpius at the age of 19 Myr, and some stars of varying spectral types (i.e., FG, K, and M type) show different spin-down rates after the age of ~110 Myr. By incorporating the effects of stalled spin-down into our analysis, we develop an empirical rotation-age-color relation, which is valid with ages between 700-4000 Myr and colors corresponding to a range of 0.5 < ${({G}_{\mathrm{BP}}-{G}_{\mathrm{RP}})}_{0}$ < 2.5 mag.

Keywords: star clusters; open star clusters; stellar rotation; stellar ages; binary stars
Simulation of a Solar Jet Formed from an Untwisting Flux Rope Interacting with a Null Point

Coronal jets are eruptions identified by a collimated, sometimes twisted spire. They are small-scale energetic events compared with flares. Using multiwavelength observations from the Solar Dynamics Observatory/Atmospheric Imaging Assembly and a magnetogram from Hinode/Spectro-Polarimeter (Hinode/SP), we study the formation and evolution of a jet occurring on 2019 March 22 in NOAA Active Region 12736. A zero-β magnetohydrodynamic simulation is conducted to probe the initiation mechanisms and appearance of helical motion during this jet event. As the simulation reveals, there are two pairs of field lines at the jet base, indicating two distinct magnetic structures. One structure outlines a flux rope lying low above the photosphere in the north of a bald patch region, and the other structure shows a null point high in the corona in the south. The untwisting motions of the observed flux rope were recovered by adding an anomalous (artificial) resistivity in the simulation. A reconnection occurs at the bald patch in the flux rope structure, which is moving upward and simultaneously encounters the field lines of the null point structure. The interaction of the two structures results in the jet, while the twist of the flux rope is transferred to the jet by the reconnected field lines. The rotational motion of the flux rope is proposed to be an underlying trigger of this process and responsible for helical motions in the jet spire.

Keywords: solar magnetic fields; solar magnetic reconnection; magnetohydrodynamics; solar activity; solar active regions
Determination of the Local Hubble Constant from Virgo Infall Using TRGB Distances

An independent determination of H0 is crucial given the growing tension between the Hubble constant, H0, derived locally and that determined from the modeling of the cosmic microwave background (CMB) originating in the early universe. In this work, we present a new determination of H0 using velocities and tip of the red giant branch (TRGB) distances to 33 galaxies located between the Local Group and the Virgo cluster. We use a model of the infall pattern of the local Hubble flow modified by the Virgo mass, which is given as a function of the cosmological constants (H0, ΩΛ), the radius of the zero-velocity surface R0, and the intrinsic velocity dispersion, σv. Fitting velocities and TRGB distances of 33 galaxies to the model, we obtain H0 = 65.8 ± 3.5 (stat) ± 2.4 (sys) km s-1 Mpc-1 and R0 = 6.76 ± 0.35 Mpc. Our local H0 is consistent with the global H0 determined from CMB radiation, showing no tension. In addition, we present new TRGB distances to NGC 4437 and NGC 4592, which are located near the zero-velocity surface: D = 9.28 ± 0.39 Mpc and D = 9.07 ± 0.27 Mpc, respectively. Their spatial separation is 0.29 ${}_{-0.03}^{+0.30}$ Mpc, suggesting that they form a physical pair.

Keywords: distance indicators; stellar distance; galaxy stellar halos; galaxy stellar content; virgo cluster; cosmology; hubble constant; cosmological parameters