adsabs/SciX_UAT_keywords huggingface dataset:
A SPectroscopic survey of biased halos In the Reionization Era (ASPIRE): Impact of Galaxies on the Circumgalactic Medium Metal Enrichment at z > 6 Using the JWST and VLT

We characterize the multiphase circumgalactic medium (CGM) and galaxy properties at z = 6.0–6.5 in four quasar fields from the James Webb Space Telescope A SPectroscopic survey of biased halos In the Reionization Era (ASPIRE) program. We use the Very Large Telescope/X-shooter spectra of quasar J0305–3150 to identify one new metal absorber at z = 6.2713 with multiple transitions (O I, Mg II, Fe II, and C II). They are combined with the published absorbing systems in Davies et al. at the same redshift range to form a sample of nine metal absorbers at z = 6.03–6.49. We identify eight galaxies within 1000 km s‑1 and 350 kpc around the absorbing gas from the ASPIRE spectroscopic data, with their redshifts secured by [O III] (λ λ4959, 5007) doublets and Hβ emission lines. Our spectral energy distribution fitting indicates that the absorbing galaxies have stellar masses ranging from 107.2 to 108.8 M ⊙ and metallicity between 0.02 and 0.4 solar. Notably, the z = 6.2713 system in the J0305–3150 field resides in a galaxy overdensity region, which contains two (tentatively) merging galaxies within 350 kpc and seven galaxies within 1 Mpc. We measure the relative abundances of α elements to iron ([α/Fe]) and find that the CGM gas in the most overdense region exhibits a lower [α/Fe] ratio. Our modeling of the galaxy's chemical abundance favors a top-heavy stellar initial mass function and hints that we may be witnessing the contribution of the first generation of Population III stars to the CGM at the end of the reionization epoch.

Keywords: circumgalactic medium; population iii stars; high-redshift galaxies
Accretion Disk Outflow during the X-Ray Flare of the Super-Eddington Active Nucleus of I Zwicky 1

We present a detailed X-ray spectral analysis of the narrow-line Seyfert 1 galaxy I Zwicky 1, for which a sequence of X-ray flares were detected during a long, simultaneous observation acquired with XMM-Newton and NuSTAR. We determine the key parameters of the inner accretion disk and hot corona in the context of the disk reflection model, which successfully captures the evolution of the X-ray corona during the X-ray flare. Using a thermal Comptonization continuum model, we confirm that the corona rapidly cooled from ~200 to ~15 keV, likely a consequence of strong pair production and runaway in a disk-like corona during the X-ray flare, when the nonthermal electron fraction rapidly increased. We detect multiple variable blueshifted absorption features arising from outflowing material along the line of sight to I Zwicky 1, which we associated with ionized winds and ultrafast outflows. One of the ionized winds may be newly launched just after the X-ray flare. During the 5 days of NuSTAR observations, the ionization state and velocity of these outflows followed a relation of the form ξ ~ v w 3.24, as expected from a super-Eddington wind. Comparison with molecular gas and warm ionized gas observations suggests that the kinematics of the ionized winds are consistent with a sufficiently cooled, momentum-driven outflow. Considering the dynamical feedback from these outflows can account for the significantly undermassive black hole in I Zwicky 1.

Keywords: active galaxies; quasars; black holes; accretion
Enhancing Exoplanet Ephemerides by Leveraging Professional and Citizen Science Data: A Test Case with WASP-77 A b

We present an updated ephemeris, and physical parameters, for the exoplanet WASP-77 A b. In this effort, we combine 64 ground- and space-based transit observations, 6 space-based eclipse observations, and 32 radial velocity observations to produce this target's most precise orbital solution to date aiding in the planning of James Webb Space Telescope and Ariel observations and atmospheric studies. We report a new orbital period of 1.360029395 ± 5.7 × 10‑8 days, a new mid-transit time of 2459957.337860 ± 4.3 × 10‑5 Barycentric Julian Date in the Barycentric Dynamical Timescale (BJDTDB) and a new mid-eclipse time of 2459956.658192 ± 6.7 × 10‑5 BJDTDB. Furthermore, the methods presented in this study reduce the uncertainties in the planet's mass 1.6654 ± 4.5 × 10‑3 M Jup and orbital period 1.360029395 ± 5.7 × 10‑8 days by factors of 15.1 and 10.9, respectively. Through a joint fit analysis comparison of transit data taken by space-based and citizen science-led initiatives, our study demonstrates the power of including data collected by citizen scientists compared to a fit of the space-based data alone. Additionally, by including a vast array of citizen science data from ExoClock, Exoplanet Transit Database, and Exoplanet Watch, we can increase our observational baseline and thus acquire better constraints on the forward propagation of our ephemeris than what is achievable with Transiting Exoplanet Survey Satellite data alone.

Keywords: exoplanet detection methods; exoplanets; hot jupiters; radial velocity; transit photometry; transit timing variation method
HIP 65426 is a High-frequency Delta Scuti Pulsator in Plausible Spin–Orbit Alignment with its Directly Imaged Exoplanet

HIP 65426 hosts a young giant planet that has become the first exoplanet directly imaged with JWST. Using time-series photometry from the Transiting Exoplanet Survey Satellite (TESS), we classify HIP 65426 as a high-frequency δ Scuti pulsator with a possible large-frequency separation of Δν = 7.23 ± 0.02 cycles day‑1. We check the TESS data for pulsation-timing variations and use the nondetection to estimate a 95% dynamical mass upper limit of 12.8 M Jup for HIP 65426 b. We also identify a low-frequency region of signal that we interpret as stellar latitudinal differential rotation with two rapid periods of 7.85 ± 0.08 hr and 6.67 ± 0.04 hr. We use our TESS rotation periods together with published values of radius and to jointly measure the inclination of HIP 65426 to °. Our stellar inclination is consistent with the orbital inclination of HIP 65426 b ( °) at the 68% percent level based on our orbit fit using published relative astrometry. The lack of significant evidence for spin–orbit misalignment in the HIP 65426 system supports an emerging trend consistent with preferential alignment between imaged long-period giant planets and their host stars.

Keywords: delta scuti variable stars; exoplanet systems; planet hosting stars; stellar pulsations
Searching for Protoplanets around MWC 758 and MWC 480 in Br-γ Using Kernel Phase and SCExAO/CHARIS

Discovering new actively accreting protoplanets is crucial to answering open questions about planet formation. However, identifying such planets at orbital distances where they are expected to be abundant is extremely challenging, both due to the technical requirements and large distances to star-forming regions. Here we use the kernel phase interferometry (KPI) technique to search for companions around the ∼6 and ∼8 Myr old Herbig Ae stars MWC 758 and MWC 480. KPI is a data analysis technique that is sensitive to moderate asymmetries, arising from, e.g., a circumstellar disk or companions with contrasts of up to 6–8 mag, at separations down to and even below the classical Rayleigh diffraction limit (∼1.2λ/D). Using the high-spectral-resolution K-band mode of the SCExAO/CHARIS integral field spectrograph, we search for both excess Br-γ line emission and continuum emission from companions around MWC 480 and MWC 758. We are able to set limits on the presence of rapidly accreting protoplanets and brown dwarfs between 4 and 16 au, well interior to those of previous studies. In Br-γ, we set limits on excess line emission equivalent to accretion rates ranging from to . Our achievable contrasts demonstrate that KPI using SCExAO/CHARIS is a promising technique to search for giant accreting protoplanets at smaller separations compared to conventional imaging.

Keywords: exoplanet formation; protoplanetary disks; young stellar objects; interferometry; astronomy data analysis; high contrast techniques; spectroscopy
Magnetic Field Information in the Near-ultraviolet Fe II Lines of the CLASP2 Space Experiment

We investigate theoretically the circular polarization signals induced by the Zeeman effect in the Fe II lines of the 279.3-280.7 nm spectral range of the CLASP2 space experiment and their suitability to infer solar magnetic fields. To this end, we use a comprehensive Fe II atomic model to solve the problem of the generation and transfer of polarized radiation in semiempirical models of the solar atmosphere, comparing the region of formation of the Fe II spectral lines with those of the Mg II h and k and the Mn I resonance lines. These are present in the same near-ultraviolet (near-UV) spectral region and allowed the mapping of the longitudinal component of the magnetic field (B L) through several layers of the solar chromosphere in an active region plage. We compare our synthetic intensity profiles with observations from the IRIS and CLASP2 missions, proving the suitability of our model atom to characterize these Fe II spectral lines. The CLASP2 observations show two Fe II spectral lines at 279.79 and 280.66 nm with significant circular polarization signals. We demonstrate the suitability of the weak-field approximation applied to the Stokes I and V profiles of these Fe II lines to infer B L in the plage atmosphere. We conclude that the near-UV spectral region of CLASP2 allows us to determine B L from the upper photosphere to the top of the chromosphere of active region plages.

Keywords: spectropolarimetry; solar magnetic fields; solar chromosphere; solar photosphere
ALMA Reveals Spatially Resolved Properties of Molecular Gas in the Host Galaxy of FRB 20191001A at z = 0.2340

We report the detection of the CO(2–1) emission line with a spatial resolution of 0.″9 (3.5 kpc) from the host galaxy of the fast radio burst (FRB), FRB 20191001A at z = 0.2340, using the Atacama Large Millimeter/submillimeter Array. This is the first detection of spatially resolved CO emission from the host galaxy of an FRB at a cosmological distance. The inferred molecular gas mass of the host galaxy is (2.3 ± 0.4) × 1010 M ⊙, indicating that it is gas-rich, as evidenced by the measured molecular gas fraction μ gas = 0.50 ± 0.22. This molecular gas mass and the star formation rate of the host, SFR = (8.06 ± 2.42) M ⊙ yr‑1, differ from those observed in the other FRB host galaxies with the average M gas = 9.6 × 108 M ⊙ and SFR = 0.90M ⊙ yr‑1. This lends further credibility to the hypothesis that FRBs may originate from single or multiple progenitors across a diverse range of galaxy environments. Based on the observed velocity field modeling, we find that the molecular gas disk is dominated by an ordered circular rotation, despite the fact that the host galaxy has a gas-rich companion galaxy with a projected separation of ∼25 kpc. The formation of the FRB's progenitor might not have been triggered by this interaction. We derive the 3σ upper limit of the molecular gas column density at the FRB detection site to be <2.1 × 1021 cm‑2 with a 3σ upper limit.

Keywords: radio transient sources; radio bursts; extragalactic radio sources; co line emission; molecular gas; interstellar medium
Evidence for Hidden Nearby Companions to Hot Jupiters

The first discovered extrasolar worlds-giant, "hot Jupiter" planets on short-period orbits-came as a surprise to solar system-centric models of planet formation, prompting the development of new theories for planetary system evolution. The near absence of observed nearby planetary companions to hot Jupiters has been widely quoted as evidence in support of high-eccentricity tidal migration, a framework in which hot Jupiters form further out in their natal protoplanetary disks before being thrown inward with extremely high eccentricities, stripping systems of any close-in planetary companions. In this work, we present new results from a search for transit timing variations across the full 4 yr Kepler data set, demonstrating that at least 12% ± 6% of hot Jupiters have a nearby planetary companion. This subset of hot Jupiters is expected to have a quiescent dynamical history such that the systems could retain their nearby companions. We also demonstrate a ubiquity of nearby planetary companions to warm Jupiters (≥70% ± 16%), indicating that warm Jupiters typically form quiescently. We conclude by combining our results with existing observational constraints to propose an "eccentric migration" framework for the formation of short-period giant planets through postdisk dynamical sculpting in compact multiplanet systems. Our framework suggests that hot Jupiters constitute the natural end stage for giant planets spanning a wide range of eccentricities, with orbits that reach small enough periapses-either from their final orbital configurations in the disk phase or from eccentricity excitation in the postdisk phase-to trigger efficient tidal circularization.

Keywords: hot jupiters; exoplanets
Sizes of Lensed Lower-luminosity z = 4-8 Galaxies from the Hubble Frontier Field Program

We constrain the rest-UV size-luminosity relation for star-forming galaxies at z ~ 4 and z ~ 6, 7, and 8 identified behind clusters from the Hubble Frontier Fields (HFF) program. The size-luminosity relation is key to deriving accurate luminosity functions (LF) for faint galaxies. Making use of the latest lensing models and full data set for these clusters, lensing-corrected sizes and luminosities are derived for 68 z ~ 4, 184 z ~ 6, 93 z ~ 7, and 53 z ~ 8 galaxies. We show that size measurements can be reliably measured up to linear magnifications of ~30×, where the lensing models are well calibrated. The sizes we measure span a >1 dex range, from <50 pc to ≳500 pc. Uncertainties are based on both the formal fit errors and systematic differences between the public lensing models. These uncertainties range from ~10 pc for the smallest sources to 100 pc for the largest. Using a forward-modeling procedure to model the impact of incompleteness and magnification uncertainties, we characterize the size-luminosity relation at both z ~ 4 and z ~ 6-8. We find that the source sizes of star-forming galaxies at z ~ 4 and z ~ 6-8 scale with luminosity L as L 0.54±0.08 and L 0.40±0.04, respectively, such that lower-luminosity (≳-18 mag) galaxies are smaller than expected from extrapolating the size-luminosity relation at high luminosities (≲-18 mag). The new evidence for a steeper size-luminosity relation (3σ) adds to earlier evidence for small sizes based on the prevalence of highly magnified galaxies in high-shear regions, theoretical arguments against upturns in the LFs, and other independent determinations of the size-luminosity relation from the HFF clusters.

Keywords: gravitational lensing; dwarf galaxies
The Galactic Plane Infrared Polarization Survey (GPIPS): Data Release 4

The Galactic Plane Infrared Polarization Survey (GPIPS) seeks to characterize the magnetic field in the dusty Galactic disk using near-infrared stellar polarimetry. All GPIPS observations were completed using the 1.83 m Perkins telescope and Mimir instrument. GPIPS observations surveyed 76 deg2 of the northern Galactic plane, from Galactic longitudes 18°-56° and latitudes -1° to +1°, in the H band (1.6 μm). Surveyed stars span 7th-16th mag, resulting in nearly 10 million stars with measured linear polarizations. Of these stars, ones with mH < 12.5 mag and polarization percentage uncertainties under 2% were judged to be high quality and number over one million. GPIPS data reveal plane-of-sky magnetic field orientations for numerous interstellar clouds for AV values to ∼30 mag. The average sky separation of stars with mH < 12.5 mag is about 30″, or about 60 per Planck polarization resolution element. Matching to Gaia DR2 showed the brightest GPIPS stars are red giants with distances in the 0.6-7.5 kpc range. Polarization orientations are mostly parallel to the Galactic disk, with some zones showing significant orientation departures. Changes in orientations are stronger as a function of Galactic longitude than of latitude. Considered at 10' angular scales, directions that show the greatest polarization fractions and narrowest polarization position angle distributions are confined to about 10 large, coherent structures that are not correlated with star-forming clouds. The GPIPS polarimetric and photometric data products (Data Release 4 catalogs and images) are publicly available for over 13 million stars.

Keywords: magnetic fields; starlight polarization; polarimetry; surveys; interstellar magnetic fields; galaxy disks; milky way disk
Toward Accurate Modeling of Galaxy Clustering on Small Scales: Halo Model Extensions and Lingering Tension

This paper represents an effort to provide robust constraints on the galaxy-halo connection and simultaneously test the Planck ΛCDM cosmology using a fully numerical model of small-scale galaxy clustering. We explore two extensions to the standard Halo Occupation Distribution model: assembly bias, whereby halo occupation depends on both halo mass and the larger environment, and velocity bias, whereby galaxy velocities do not perfectly trace the velocity of the dark matter within the halo. Moreover, we incorporate halo mass corrections to account for the impact of baryonic physics on the halo population. We identify an optimal set of clustering measurements to constrain this "decorated" HOD model for both low- and high-luminosity galaxies in SDSS DR7. We find that, for low-luminosity galaxies, a model with both assembly bias and velocity bias provides the best fit to the clustering measurements, with no tension remaining in the fit. In this model, we find evidence for both central and satellite galaxy assembly bias at the 99% and 95% confidence levels, respectively. In addition, we find evidence for satellite galaxy velocity bias at the 99.9% confidence level. For high-luminosity galaxies, we find no evidence for either assembly bias or velocity bias, but our model exhibits significant tension with SDSS measurements. We find that all of these conclusions still stand when we include the effects of baryonic physics on the halo mass function, suggesting that the tension we find for high-luminosity galaxies may be due to a problem with our assumed cosmological model.

Keywords: large-scale structure of the universe; galaxy dark matter halos; galaxy groups; clustering; redshift surveys
Cold Dark Matter and Self-interacting Dark Matter Interpretations of the Strong Gravitational Lensing Object JWST-ER1

van Dokkum et al. reported the discovery of JWST-ER1, a strong lensing object at redshift z ≈ 2, using data from the James Webb Space Telescope. The lens mass within the Einstein ring is 5.9 times higher than the expected stellar mass from a Chabrier initial mass function, indicating a high dark matter density. In this work, we show that a cold dark matter halo, influenced by gas-driven adiabatic contraction, can account for the observed lens mass. We interpret the measurement of JWST-ER1 in the self-interacting dark matter scenario and show that the cross section per particle mass σ/m ≈ 0.1 cm2 g‑1 is generally favored. Intriguingly, σ/m ≈ 0.1 cm2 g‑1 can also be consistent with the strong lensing observations of early-type galaxies at redshift z ≈ 0.2, where adiabatic contraction is not observed overall.

Keywords: dark matter; strong gravitational lensing; early-type galaxies; galaxy dark matter halos
Hybrid Data-driven Magnetofrictional and Magnetohydrodynamic Simulations of an Eruptive Solar Active Region

We present the first results of the hybrid data-driven magnetofrictional (MF) and data-constrained magnetohydrodynamic (MHD) simulations of solar active region NOAA 11158, which produced an X-class flare and coronal mass ejection on 2011 February 15. First, we apply the MF approach to build the coronal magnetic configuration corresponding to the SDO/HMI photospheric magnetograms by using the JSOC PDFI_SS electric field inversions at the bottom boundary of the simulation domain. We then use the preeruptive MF state at about 1.5 hr before the observed X-class flare as the initial state for the MHD simulation, assuming a stratified polytropic solar corona. The MHD run shows that the initial magnetic configuration containing twisted magnetic fluxes and a three-dimensional (3D) magnetic null point is out of equilibrium. We find the eruption of a complex magnetic structure consisting of two magnetic flux ropes, as well as the development of flare ribbons, with their morphology being in good agreement with observations. We conclude that the combination of the data-driven MF and data-constrained MHD simulations is a useful practical tool for understanding the 3D magnetic structures of real solar ARs that are unobservable otherwise.

Keywords: solar filament eruptions; solar coronal mass ejections; solar flares; magnetohydrodynamical simulations
NGC 147 Corroborates the Break in the Stellar Mass-Stellar Metallicity Relation for Galaxies

The stellar mass-stellar metallicity relation (MZR) is an essential approach to probing the chemical evolution of galaxies. It reflects the balance between galactic feedback and gravitational potential as a function of stellar mass. However, the current MZR of local dwarf satellite galaxies (M* ≲ 108 M⊙; measured from resolved stellar spectroscopy) may not be reconcilable with that of more massive galaxies (M* ≳ 109.5 M⊙; measured from integrated-light spectroscopy). Such a discrepancy may result from a systematic difference between the two methods, or it may indicate a break in the MZR around 109 M⊙. To address this question, we measured the stellar metallicity of NGC 147 from integrated light using the Palomar Cosmic Web Imager. We compared the stellar metallicity estimates from integrated light with measurements from resolved stellar spectroscopy and found them to be consistent within 0.1 dex. On the other hand, the high-mass MZR overpredicts the metallicity by 0.6 dex at the mass of NGC 147. Therefore, our results tentatively suggest that the discrepancy between the low-mass MZR and high-mass MZR should not be attributed to a systematic difference in techniques. Instead, real physical processes cause the transition in the MZR. In addition, we discovered a positive age gradient in the innermost region and a negative metallicity gradient from the resolved stars at larger radii, suggesting a possible outside-in formation of NGC 147.

Keywords: local group; galaxy abundances; metallicity; chemical abundances; stellar abundances; dwarf elliptical galaxies
Neutrino Fluxes from Different Classes of Galactic Sources

We estimate the neutrino flux from different kinds of galactic sources and compare it with the recent diffuse neutrino flux detected by IceCube. We find that the flux from these sources may contribute to ∼20% of the IceCube neutrino flux. Most of the sources selected in this work populate the southern hemisphere, therefore a detector like KM3NeT could help in resolving the sources out of the observed diffused galactic neutrino flux.

Keywords: high energy astrophysics