Sazuna/UAT_keywords huggingface dataset:
A Candidate Dual QSO at Cosmic Noon. We report the discovery of a candidate dual QSO at z = 1.889, a redshift that is in the era known as "cosmic noon" where most of the universe's black hole and stellar mass growth occurred. The source was identified in Hubble Space Telescope WFC3/IR images of a dust-reddened QSO that showed two closely separated point sources at a projected distance of 0.″26, or 2.2 kpc. This red QSO was targeted for imaging to explore whether red QSOs are hosted by merging galaxies. We subsequently obtained a spatially resolved Space Telescope Imaging Spectrograph spectrum of the system, covering the visible spectral range, and verifying the presence of two distinct QSO components. We also obtained high-resolution radio continuum observations with the Very Long Baseline Array at 1.4 GHz (21 cm L band) and found two sources coincident with the optical positions. The sources have similar black hole masses, bolometric luminosities, and radio-loudness parameters. However, their colors and reddenings differ significantly. The redder QSO has a higher Eddington ratio, consistent with previous findings. We consider the possibility of gravitational lensing and find that it would require extreme and unlikely conditions. If confirmed as a bona fide dual QSO, this system would link dust reddening to galaxy and supermassive black hole mergers, opening up a new population in which to search for samples of dual active galactic nuclei.

Keywords: Double quasars, Quasars
The Origin of Universality in the Inner Edges of Planetary Systems. The characteristic orbital period of the innermost objects within the galactic census of planetary and satellite systems appears to be nearly universal, with P on the order of a few days. This paper presents a theoretical framework that provides a simple explanation for this phenomenon. By considering the interplay between disk accretion, magnetic field generation by convective dynamos, and Kelvin-Helmholtz contraction, we derive an expression for the magnetospheric truncation radius in astrophysical disks and find that the corresponding orbital frequency is independent of the mass of the host body. Our analysis demonstrates that this characteristic frequency corresponds to a period of P ~ 3 days although intrinsic variations in system parameters are expected to introduce a factor of a ~2-3 spread in this result. Standard theory of orbital migration further suggests that planets should stabilize at an orbital period that exceeds disk truncation by a small margin. Cumulatively, our findings predict that the periods of close-in bodies should span P ~ 2-12 days-a range that is consistent with observations.

Keywords: Magnetohydrodynamics, Exoplanet formation, Planet formation, Circumstellar disks
The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems I: High-contrast Imaging of the Exoplanet HIP 65426 b from 2 to 16 μm. We present JWST Early Release Science coronagraphic observations of the super-Jupiter exoplanet, HIP 65426b, with the Near-Infrared Camera (NIRCam) from 2 to 5 μm, and with the Mid-Infrared Instrument (MIRI) from 11 to 16 μm. At a separation of ~0.″82 (87 ${}_{-31}^{+108}$ au), HIP 65426b is clearly detected in all seven of our observational filters, representing the first images of an exoplanet to be obtained by JWST, and the first-ever direct detection of an exoplanet beyond 5 μm. These observations demonstrate that JWST is exceeding its nominal predicted performance by up to a factor of 10, depending on separation and subtraction method, with measured 5σ contrast limits of ~1 × 10-5 and ~2 × 10-4 at 1″ for NIRCam at 4.4 μm and MIRI at 11.3 μm, respectively. These contrast limits provide sensitivity to sub-Jupiter companions with masses as low as 0.3M Jup beyond separations of ~100 au. Together with existing ground-based near-infrared data, the JWST photometry are fit well by a BT-SETTL atmospheric model from 1 to 16 μm, and they span ~97% of HIP 65426b's luminous range. Independent of the choice of model atmosphere, we measure an empirical bolometric luminosity that is tightly constrained between $\mathrm{log}\left({L}_{\mathrm{bol}}/{L}_{\odot }\right)$ = -4.31 and -4.14, which in turn provides a robust mass constraint of 7.1 ± 1.2 M Jup. In totality, these observations confirm that JWST presents a powerful and exciting opportunity to characterize the population of exoplanets amenable to high-contrast imaging in greater detail.

Keywords: Exoplanet astronomy, Extrasolar gaseous planets, Exoplanets
Accelerated Structural Evolution of Galaxies in a Starbursting Cluster at z = 2.51. Structural properties of cluster galaxies during their peak formation epoch, z ~ 2-4 provide key information on whether and how the environment affects galaxy formation and evolution. Based on deep Hubble Space Telescope (HST)/Wide Field Camera 3 (WFC3) imaging toward the z = 2.51 cluster, J1001, we explore environmental effects on the structure, color gradients, and stellar populations of a statistical sample of cluster star-forming galaxies (SFGs). We find that the cluster SFGs are on average smaller than their field counterparts. This difference is most pronounced at the high-mass end (M ⋆ &gt; 1010.5  M ⊙), with nearly all of them lying below the mass-size relation of field galaxies. The high-mass cluster SFGs are also generally old, with a steep negative color gradient, indicating an early formation time likely associated with strong dissipative collapse. For low-mass cluster SFGs, we unveil a population of compact galaxies with steep positive color gradients that are not seen in the field. This suggests that the low-mass compact cluster SFGs may have already experienced strong environmental effects, e.g., tidal/ram pressure stripping, in this young cluster. These results provide evidence on the environmental effects at work in the earliest formed clusters with different roles in the formation of low- and high-mass galaxies.

Keywords: Galaxy structure, Galaxy evolution, High-redshift galaxy clusters
Spectroscopic Confirmation of CEERS NIRCam-selected Galaxies at z ≃ 8-10. We present JWST/NIRSpec prism spectroscopy of seven galaxies selected from Cosmic Evolution Early Release Science (CEERS) survey NIRCam imaging with photometric redshifts z phot &gt; 8. We measure emission line redshifts of z = 7.65 and 8.64 for two galaxies. For two other sources without securely detected emission lines we measure $z={9.77}_{-0.29}^{+0.37}$ and ${10.01}_{-0.19}^{+0.14}$ by fitting model spectral templates to the prism data, from which we detect continuum breaks consistent with Lyα opacity from a mostly neutral intergalactic medium. The presence of strong breaks and the absence of strong emission lines give high confidence that these two galaxies have redshifts z &gt; 9.6, but the redshift values derived from the breaks alone have large uncertainties given the low spectral resolution and relatively low S/N of the CEERS NIRSpec prism data. The two z ~ 10 sources observed are relatively luminous (M UV &lt; -20), with blue continua (-2.3 ≲ β ≲ -1.9) and low dust attenuation ( ${A}_{V}\simeq {0.15}_{-0.1}^{+0.3}$ ); and at least one of them has a high stellar mass for a galaxy at that redshift ( $\mathrm{log}({M}_{\star }/{M}_{\odot })\simeq {9.3}_{-0.3}^{+0.2}$ ). Considered together with spectroscopic observations of other CEERS NIRCam-selected high-z galaxy candidates in the literature, we find a high rate of redshift confirmation and low rate of confirmed interlopers (8%). Ten out of 35 z &gt; 8 candidates with CEERS NIRSpec spectroscopy do not have secure redshifts, but the absence of emission lines in their spectra is consistent with redshifts z &gt; 9.6. We find that z &gt; 8 photometric redshifts are generally in agreement (within their uncertainties) with the spectroscopic values, but also that the photometric redshifts tend to be slightly overestimated (&lt;Δz&gt; = 0.45 ± 0.11), suggesting that current templates do not fully describe the spectra of very-high-z sources. Overall, the spectroscopy solidifies photometric redshift evidence for a high spatial density of bright galaxies at z &gt; 8 compared to theoretical model predictions, and further disfavors an accelerated decline in the integrated UV luminosity density at z &gt; 8.

Keywords: Early universe, Galaxy formation, High-redshift galaxies, Galaxy evolution
The Kelvin-Helmholtz Instability at the Boundary of Relativistic Magnetized Jets. We study the linear stability of a planar interface separating two fluids in relative motion, focusing on conditions appropriate for the boundaries of relativistic jets. The jet is magnetically dominated, whereas the ambient wind is gas-pressure-dominated. We derive the most general form of the dispersion relation and provide an analytical approximation of its solution for an ambient sound speed much smaller than the jet Alfvén speed v A, as appropriate for realistic systems. The stability properties are chiefly determined by the angle ψ between the wavevector and the jet magnetic field. For ψ = π/2, magnetic tension plays no role, and our solution resembles the one of a gas-pressure-dominated jet. Here, only sub-Alfvénic jets are unstable ( $0\lt {M}_{e}\equiv (v/{v}_{{\rm{A}}})\cos \theta \lt 1$ , where v is the shear velocity and θ the angle between the velocity and the wavevector). For ψ = 0, the free energy in the velocity shear needs to overcome the magnetic tension, and only super-Alfvénic jets are unstable ( $1\lt {M}_{e}\lt \sqrt{{(1+{{\rm{\Gamma }}}_{w}^{2})/[1+({v}_{{\rm{A}}}/c)}^{2}{{\rm{\Gamma }}}_{w}^{2}]}$ , with Γ w  the wind adiabatic index). Our results have important implications for the propagation and emission of relativistic magnetized jets.

Keywords: Magnetohydrodynamics, High energy astrophysics, Plasma jets, Relativistic jets, Plasma astrophysics, Relativistic fluid dynamics
Luminosity Outburst of a High-mass Young Stellar Object Triggered by the Surrounding Radiation Field. We present observations of the 6.7 GHz methanol and 4.8 GHz formaldehyde masers toward the high-mass young stellar object G24.33+0.14 (hereafter G24). Our observations were conducted from 2019 to 2021 using the Shanghai Tianma 65 m Radio Telescope and the Very Large Array in response to the luminosity outburst event traced by these two species masers in 2019. Our results indicate that the provenance of the maser flares is unlikely to be ascribed to the protostar of G24 itself. Through analyzing NEOWISE infrared monitoring data, we identified two light curves of G24 with long-term (3083 days, ~8.5 yr) and short-term (424 days) periods. Intriguingly, 11 periodic variable sources located in the same bubble as G24 exhibiting periods comparable to the short-term period of G24 were also detected. The analysis of the spectral energy distributions of these periodic variables revealed a possible correlation between their temperature fluctuations and the surrounding radiation field that possibly emanates from the driving source of the bubble. This source could be an individual supergiant protostar of a few hundred solar masses with periodic pulsation potentially accounting for the observed short-term period in the G24 region.

Keywords: Young stellar objects, Star formation, Astrophysical masers, Interstellar masers, Protostars
Investigating Possible Binarity for GJ 229B. GJ 229B, the first type-T brown dwarf to be discovered, has presented a tension between comparisons with evolutionary models and the larger-than-expected mass and radius values derived from spectroscopic and astrometric observations. We examine the hypothesis that GJ 229B is actually a binary substellar object by using two grid-based fits using evolutionary models to explore the range of mass ratios of the possible binary components. We find that the best-fit component values are most consistent with a roughly 2:1 binary mass ratio and an age range of 2-6 Gyr. The observed temperatures, masses, and apparent radii match expected values from evolutionary models for a binary much better than a single-object model, but more detailed observations and modeling are needed to definitively confirm the binary hypothesis.

Keywords: Brown dwarfs, Binary stars, Stellar atmospheres, T dwarfs
An Observed Transition of Galaxy Spins on Void Surfaces. In linear theory, the galaxy angular momentum vectors that originate from initial tidal interactions with surrounding matter distribution intrinsically develop perpendicular alignments with the directions of maximum matter compression, regardless of galaxy mass. In simulations, however, galaxy spins exhibit parallel alignments in the mass range lower than a certain threshold, which depends on redshift, web type, and background cosmology. We show that the observed three-dimensional spins of the spiral galaxies located on the void surfaces from the Sloan Digital Sky Survey indeed transit from perpendicular to parallel alignments with the directions toward the nearest void centers at the threshold zone, $9.51\leqslant \mathrm{log}[{M}_{\mathrm{th},\star }/(\,{h}^{-1}\,{M}_{\odot })]\leqslant 10.03$ . This study presents the first direct observational evidence for the occurrence of mass-dependent spin transition of real galaxies with respect to non-filamentary structures of the cosmic web, opening a way to constrain the initial conditions of the early universe by measuring the spin transition threshold.

Keywords: Cosmology, Large-scale structure of the universe
Search for Astrophysical Electron Antineutrinos in Super-Kamiokande with 0.01% Gadolinium-loaded Water. We report the first search result for the flux of astrophysical electron antineutrinos for energies ${ \mathcal O }(10)\,\mathrm{MeV}$ in the gadolinium-loaded Super-Kamiokande (SK) detector. In 2020 June, gadolinium was introduced to the ultrapure water of the SK detector in order to detect neutrons more efficiently. In this new experimental phase, SK-Gd, we can search for electron antineutrinos via inverse beta decay with efficient background rejection thanks to the high efficiency of the neutron tagging technique. In this paper, we report the result for the initial stage of SK-Gd, during 2020 August 26, and 2022 June 1 with a 22.5 × 552 kton · day exposure at 0.01% Gd mass concentration. No significant excess over the expected background in the observed events is found for the neutrino energies below 31.3 MeV. Thus, the flux upper limits are placed at the 90% confidence level. The limits and sensitivities are already comparable with the previous SK result with pure water (22.5 × 2970 kton · day) owing to the enhanced neutron tagging. Operation with Gd increased to 0.03% started in 2022 June.

Keywords: Neutrino astronomy, Supernova neutrinos
The NANOGrav 12.5 yr Data Set: Bayesian Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries. Pulsar timing array collaborations, such as the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), are seeking to detect nanohertz gravitational waves emitted by supermassive black hole binaries formed in the aftermath of galaxy mergers. We have searched for continuous waves from individual circular supermassive black hole binaries using NANOGrav's recent 12.5 yr data set. We created new methods to accurately model the uncertainties on pulsar distances in our analysis, and we implemented new techniques to account for a common red-noise process in pulsar timing array data sets while searching for deterministic gravitational wave signals, including continuous waves. As we found no evidence for continuous waves in our data, we placed 95% upper limits on the strain amplitude of continuous waves emitted by these sources. At our most sensitive frequency of 7.65 nHz, we placed a sky-averaged limit of h 0 &lt; (6.82 ± 0.35) × 10-15, and h 0 &lt; (2.66 ± 0.15) × 10-15 in our most sensitive sky location. Finally, we placed a multimessenger limit of ${ \mathcal M }\lt (1.41\pm 0.02)\times {10}^{9}\,{M}_{\odot }$ on the chirp mass of the supermassive black hole binary candidate 3C 66B.

Keywords: Supermassive black holes, Astronomy data analysis, Gravitational waves, Millisecond pulsars
TOI-1859b: A 64 Day Warm Jupiter on an Eccentric and Misaligned Orbit. Warm Jupiters are close-in giant planets with relatively large planet-star separations (i.e., 10 &lt; a/R ⋆ &lt; 100). Given their weak tidal interactions with their host stars, measurements of stellar obliquity may be used to probe the initial obliquity distribution and dynamical history for close-in gas giants. Using spectroscopic observations, we confirm the planetary nature of TOI-1859b and determine the stellar obliquity of TOI-1859 to be λ = 38.9 ${}_{-2.7}^{+2.8}$ ° relative to its planetary companion using the Rossiter-McLaughlin effect. TOI-1859b is a 64 day warm Jupiter orbiting around a late F dwarf and has an orbital eccentricity of 0.57 ${}_{-0.16}^{+0.12}$ inferred purely from transit light curves. The eccentric and misaligned orbit of TOI-1859b is likely an outcome of dynamical interactions, such as planet-planet scattering and planet-disk resonance crossing.

Keywords: Exoplanet dynamics, Radial velocity, Transit photometry, Extrasolar gaseous giant planets
Jetted and Turbulent Stellar Deaths: New LVK-detectable Gravitational-wave Sources. Upcoming LIGO-Virgo-KAGRA (LVK) observing runs are expected to detect a variety of inspiralling gravitational-wave (GW) events that come from black hole and neutron star binary mergers. Detection of noninspiral GW sources is also anticipated. We report the discovery of a new class of noninspiral GW sources-the end states of massive stars-that can produce the brightest simulated stochastic GW burst signal in the LVK bands known to date, and could be detectable in LVK run A+. Some dying massive stars launch bipolar relativistic jets, which inflate a turbulent energetic bubble-cocoon-inside of the star. We simulate such a system using state-of-the-art 3D general relativistic magnetohydrodynamic simulations and show that these cocoons emit quasi-isotropic GW emission in the LVK band, ~10-100 Hz, over a characteristic jet activity timescale ~10-100 s. Our first-principles simulations show that jets exhibit a wobbling behavior, in which case cocoon-powered GWs might be detected already in LVK run A+, but it is more likely that these GWs will be detected by the third-generation GW detectors with an estimated rate of ~10 events yr-1. The detection rate drops to ~1% of that value if all jets were to feature a traditional axisymmetric structure instead of a wobble. Accompanied by electromagnetic emission from the energetic core-collapse supernova and the cocoon, we predict that collapsars are powerful multimessenger events.

Keywords: Gamma-ray bursts, Core-collapse supernovae, Stellar jets, Relativistic jets, Gravitational wave sources, Gravitational wave astronomy, Gravitational waves, LIGO, Magnetohydrodynamical simulations
Millimeter Observations of the Type II SN 2023ixf: Constraints on the Proximate Circumstellar Medium. We present 1.3 mm (230 GHz) observations of the recent and nearby Type II supernova, SN 2023ixf, obtained with the Submillimeter Array (SMA) at 2.6-18.6 days after explosion. The observations were obtained as part the SMA Large Program, POETS (Pursuit of Extragalactic Transients with the SMA). We do not detect any emission at the location of SN 2023ixf, with the deepest limits of L  ν (230 GHz) ≲ 8.6 × 1025 erg s-1 Hz-1 at 2.7 and 7.7 days, and L  ν (230 GHz) ≲ 3.4 × 1025 erg s-1 Hz-1 at 18.6 days. These limits are about a factor of 2 times dimmer than the millimeter emission from SN 2011dh (IIb), about 1 order of magnitude dimmer compared to SN 1993J (IIb) and SN 2018ivc (IIL), and about 30 times dimmer than the most luminous nonrelativistic SNe in the millimeter band (Type IIb/Ib/Ic). Using these limits in the context of analytical models that include synchrotron self-absorption and free-free absorption, we place constraints on the proximate circumstellar medium around the progenitor star, to a scale of ~2 × 1015 cm, excluding the range $\dot{M}\sim \mathrm{few}\times {10}^{-6}-{10}^{-2}$ M ⊙ yr-1 (for a wind velocity, v  w  = 115 km s-1, and ejecta velocity, v ej ~ (1 - 2) × 104 km s-1). These results are consistent with an inference of the mass-loss rate based on optical spectroscopy (~2 × 10-2 M ⊙ yr-1 for v  w  = 115 km s-1), but are in tension with the inference from hard X-rays (~7 × 10-4 M ⊙ yr-1 for v  w  = 115 km s-1). This tension may be alleviated by a nonhomogeneous and confined CSM, consistent with results from high-resolution optical spectroscopy.

Keywords: Core-collapse supernovae, Type II supernovae, Massive stars, Stellar mass loss, Circumstellar matter, Supernovae
JWST Peers into the Class I Protostar TMC1A: Atomic Jet and Spatially Resolved Dissociative Shock Region. Outflows and winds launched from young stars play a crucial role in the evolution of protostars and the early stages of planet formation. However, the specific details of the mechanism behind these phenomena, including how they affect the protoplanetary disk structure, are still debated. We present JWST NIRSpec integral field unit observations of atomic and H2 lines from 1 to 5.1 μm toward the low-mass protostar TMC1A. For the first time, a collimated atomic jet is detected from TMC1A in the [Fe II] line at 1.644 μm along with corresponding extended H2 2.12 μm emission. Toward the protostar, we detected spectrally broad H I and He I emissions with velocities up to 300 km s-1 that can be explained by a combination of protostellar accretion and a wide-angle wind. The 2 μm continuum dust emission, H I, He I, and O I all show emission from the illuminated outflow cavity wall and scattered line emission. These observations demonstrate the potential of JWST to characterize and reveal new information about the hot inner regions of nearby protostars; in this case, a previously undetected atomic wind and ionized jet in a well-known outflow.

Keywords: Protostars, Young stellar objects, Jets, H I line emission
Ryugu's Anhydrous Ingredients and Their Spectral Link to Primitive Dust from the Outer Solar System. Ryugu is a second-generation C-type asteroid formed by the reassembly of fragments of a previous larger body in the main asteroid belt. While the majority of Ryugu samples returned by Hayabusa2 are composed of a lithology dominated by aqueously altered minerals, clasts of pristine olivine and pyroxene remain in the least-altered lithologies. These clasts are objects of great interest for revealing the composition of the dust from which the original building blocks of Ryugu's parent asteroid formed. Here we show that some grains rich in olivine, pyroxene, and amorphous silicates discovered in one millimeter-sized stone of Ryugu have infrared spectra similar to the D-type asteroid Hektor (a Jupiter Trojan), to comet Hale-Bopp, and to some anhydrous interplanetary dust particles of probable cometary origin. This result indicates that Ryugu's primary parent body incorporated anhydrous ingredients similar to the building blocks of asteroids (and possibly some comets) formed in the outer solar system, and that Ryugu retained valuable information on the formation and evolution of planetesimals at different epochs of our solar system's history.

Keywords: Dust composition, Asteroids, Infrared spectroscopy, Laboratory astrophysics, Meteorites