Sazuna/UAT_keywords huggingface dataset:
ALMA Reveals Bright Circumgalactic Emission and a Biconical Outflow in z ∼ 6.4 Quasar PSOJ183+05. Understanding gas flows between galaxies and their surrounding circumgalactic medium (CGM) is crucial to unveil the mechanisms regulating galaxy evolution, especially in the early Universe. However, observations of the CGM around massive galaxies at z &gt; 6 remain limited, particularly in the cold gas phase. In this work, we present multiconfiguration Atacama Large Millimeter/submillimeter Array (ALMA) observations of [C II]λ158 μm and millimeter continuum emission in the z ∼ 6.4 quasar PSOJ183+05. We find clumpy [C II] emission, tracing gas up to a ∼6 kpc radius, consistent with the interface region between the interstellar medium (ISM) and CGM. The [C II] kinematics shows a rotating disk and a high-velocity, biconical outflow extending up to 5 kpc. The inferred mass outflow rate is  Ṁof∼930 M⊙ yr−1, among the highest at z &gt; 6, and comparable to the star formation rate. These findings suggest that quasar-driven outflows can rapidly transfer energy and momentum to the CGM, without immediately quenching star formation in the host-galaxy ISM. This supports a delayed feedback scenario, in which outflows reshape CGM conditions and regulate future gas accretion over longer timescales. We find that neither the high-velocity component nor the extended CGM emission in PSOJ183+05 are recovered when using the high-resolution data set alone, which may explain the conflicting results reported regarding [C II] sizes and the detection of outflows at z ≳ 6. Combining multiconfiguration ALMA data with observations from JWST and the Multi Unit Spectroscopic Explorer will be crucial to map the CGM across its different phases and build a comprehensive picture of the baryon cycle in the first massive galaxies.

Keywords: Quasars, Emission line galaxies, Galaxy kinematics, Galaxy evolution, Circumgalactic medium, High-redshift galaxies, Interferometry
Simultaneous Optical and Radio Observations of a Large Stellar Flare on EV Lac. We present simultaneous optical and radio observations of a large stellar flare on the M dwarf EV Lac, captured between 12:00 and 15:00 UT on 2022 October 25. This event was jointly monitored with the 85 cm and 2.16 m optical telescopes at the Xinglong Observatory, the Five-hundred-meter Aperture Spherical Radio Telescope (FAST), and the Transiting Exoplanet Survey Satellite, enabling a comprehensive view of flare energy release and dynamic evolution. The flare persisted for 138 minutes with a bolometric energy exceeding 1.7 × 1033 erg and exhibited a double-peaked light curve. Temporal Hα line profiles show Stark broadening and red asymmetry with a redshift of ∼50 km s‑1 near the first flare peak, suggesting downward plasma motion possibly due to chromospheric condensation. Enhanced blue wing emission near the second peak reaches a maximum blueshift of ‑240 km s‑1, indicating a stellar prominence eruption with an estimated mass of 7.3 × 1018–3.3 × 1019 g. Flare blackbody temperature estimates indicate a peak of 12,500 K during the first peak, oscillating between 5500 K and 8100 K near the second peak, and cooling to 3700 K afterward. FAST radio observations reveal positive frequency-drifting, highly polarized bursts consistent with electron cyclotron maser emission modulated by stellar rotation, indicating magnetically trapped energetic electrons during the flare. This unique observation campaign provides a comprehensive view of plasma heating, plasma motions, and electron acceleration during a large stellar flare, offering new insights into the multiwavelength evolution of flare-related plasma processes in stellar atmospheres.

Keywords: Stellar coronal mass ejections, Solar filament eruptions, Solar coronal mass ejections, Stellar flares, Spectroscopy
Turbulence and Magnetic Reconnection in Relativistic Multispecies Plasmas. Simulations of relativistic plasmas traditionally focus on the dynamics of two-species mixtures of charged particles under the influence of external magnetic fields and those generated by particle currents. However, the extreme conditions of astrophysical plasmas near compact objects, such as black holes and neutron stars, are often characterized by mixtures of electrons, protons, and positrons, whose dynamics can differ significantly, because of the considerable mass contrast. We present the first two-dimensional particle-in-cell simulations of relativistic turbulence and magnetic reconnection in a three-species plasma, varying the relative abundances of electrons, protons, and positrons, while employing realistic mass ratios to achieve unprecedented accuracy. We find that turbulence leads to the formation of magnetic islands, current sheets, and plasmoids. Reconnection occurs between these structures, with plasma composition playing a key role in determining the number of reconnection sites and their energy conversion efficiency. In particular, as the proton fraction increases, very small-scale features of the turbulence are washed out, while global dissipative effects are amplified. Finally, using a novel generalization of Ohm's law for a relativistic multispecies plasma, we find that the reconnection rate is primarily governed by the electric fields associated with the divergence of the positron and electron pressure tensors. These results provide new insights into dissipation and particle acceleration in turbulent relativistic plasmas, such as those near black holes and neutron stars, and can be used to interpret their high-energy emission and phenomenology.

Keywords: Space plasmas, Plasma astrophysics, High energy astrophysics
Two Types of 1/f Range in Solar Wind Turbulence. The 1/f noise is a ubiquitous phenomenon in natural systems. Since the advent of space exploration, the 1/f range has been consistently observed in in situ solar wind measurements throughout the heliosphere, sparking decades of debate regarding its origin. Recent Parker Solar Probe observations near the Alfvén surface have revealed a systematic absence of the 1/f range above 10‑4 Hz in pristine solar wind, providing a unique opportunity to investigate its origin in solar wind turbulence. Despite numerous observations of the 1/f range at varying frequencies, no study has systematically examined its properties across different solar wind conditions. Here, we identify two distinct types of 1/f ranges in solar wind turbulence: the fast/Alfvénic wind type and the slow/mixed wind type. The fast/Alfvénic type appears to be an intrinsic feature of Alfvénic turbulence, while the slow/mixed type resembles classical flicker noise. For the fast/Alfvénic type, we find a near-perfect WKB evolution of the frequency-averaged fluctuation amplitude and an intriguing migration pattern in frequency space. For the slow/mixed type, we examine the solar cycle dependence of the 1/f noise using the OMNI (LRO) data set spanning solar cycles 22–25. We also analyze the autocorrelation function of the magnetic field vectors and identify a clear relationship between the 1/f range and the decline in correlation, as well as unexpected resonance peaks in the autocorrelation function.

Keywords: Slow solar wind, Fast solar wind, Interplanetary turbulence, Solar wind, Alfven waves
Carbon-rich Sub-Neptune Interiors Are Compatible with JWST Observations. Many possible interior compositions exist for sub-Neptunes: ice-poor, ice-rich, and water-dominated interiors can all match the measured masses and radii. Motivated by a recent theory of carbon-rich planet formation outside the refractory organic carbon "soot line" and observations of carbon-rich protoplanetary disks around late M dwarfs, we propose another possible sub-Neptune composition: a carbon-rich composition consisting of an iron-silicate core, a carbon layer, and a hydrogen/helium-dominated envelope. We show that the interiors of three prototypical sub-Neptunes with high-quality spectral observations—TOI-270 d, GJ 1214 b, and K2-18 b—are consistent with carbon-rich compositions if they have ≤100 times solar metallicity atmospheres. We further show that carbon-rich interiors lead to atmospheric compositions that match Hubble Space Telescope and JWST observations. Simulated carbon-rich TOI-270 d transmission spectra pass the χ2 test under a wide range of C/O, haze, and cloud scenarios. K2-18 b spectral models are broadly consistent with observations but require additional sources for carbon species to be fully compatible. GJ 1214 b models, however, are incompatible with observations, ruling out a carbon-rich interior composition, if the atmosphere of the planet is primordial and reflects the interior C/O.

Keywords: Exoplanets, Carbon planets, Mini Neptunes, Planetary interior, Exoplanet atmospheres
ARTEMIS Observations of Electrostatic Shocks inside the Lunar Wake. When the solar wind encounters the Moon, a plasma void forms downstream of it, known as the lunar wake. In regions where the magnetic field is quasi-parallel to the plasma─vacuum boundary normal, plasma refills the wake primarily along magnetic field lines. As faster electrons outpace slower ions, an ambipolar electric field is generated, accelerating ions and decelerating electrons. Recent particle-in-cell simulations have shown that when accelerated supersonic ion beams from opposite sides of the wake meet near the wake center, electrostatic shocks may form, decelerating ions and heating electrons into flat-top velocity distributions. Using data from the Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun spacecraft, we present the first observational evidence of the predicted electrostatic shocks. Near the wake center of one event, we observed an electrostatic solitary structure with an amplitude of ∼2 mV m−1 and a spatial scale of ∼50 local Debye lengths. This structure generated a potential increase of ∼50 V from upstream to downstream, heating incoming electrons by ∼50 eV in the parallel direction while decelerating ions by ∼60 km s−1, leading to a density enhancement. At a second event representing a more evolved stage, we observed more dissipated structures dominated by strong electrostatic waves, with persistent potential increases driving continued field-aligned electron heating and ion deceleration. These observations confirm simulation predictions of electrostatic shock formation and the associated particle dynamics within the lunar wake, with potential applications to understanding plasma interactions around other airless celestial bodies.

Keywords: Space plasmas, Shocks, Plasma physics, Lunar science
The Milky Way Is a Less Massive Galaxy—New Estimates of the Milky Way's Local and Global Stellar Masses. Stellar mass is the most fundamental property of a galaxy. While it has been robustly measured for millions of external galaxies, it remains poorly constrained for the Milky Way because of the strong selection effect from our inside perspective. In this work, we reconstruct the intrinsic vertical mass density profile in the solar neighborhood and the radial mass density profile across the entire Galaxy using data from the Gaia and APOGEE surveys, following careful correction for the selection function. The local density profile exhibits strong north–south asymmetry in the geometric thick disk regime and increases steeply toward the disk midplane, favoring an exponential model over the sech2 model. Integrating the local vertical density profile yields a surface stellar mass density of 31.563 ± 2.813(syst.) ± 0.024(stoch.) M⊙ pc‑2, of which 25.074 and 6.489 M⊙ pc‑2 correspond to living stars and stellar remnants, respectively. The radial surface mass density profile of the Milky Way shares the same flat inner component as observed in the brightness profile. With this mass density profile and local mass density from Gaia, we derive a new estimate of the total stellar mass of the Milky Way of 2.607 ± 0.353(syst.) ± 0.085(stoch.) × 1010 M⊙, a factor of 2 lower than the previous results. This discrepancy arises primarily from the inner disk profile, which was previously unavailable and extrapolated from the outer disk profile. The lower stellar mass estimate of the Milky Way significantly reduces its rarity in terms of supermassive black hole mass among external galaxies and implies a larger dark-matter-to-baryon mass ratio in the inner Galaxy.

Keywords: Galaxy stellar content, Milky Way disk, Solar neighborhood, Milky Way Galaxy
Unveiling a Population of Strong Galaxy─Galaxy Lensed, Faint Dusty Star-forming Galaxies. The measurements of the number density of galaxy─galaxy strong lenses can be used to put statistical constraints on the foreground mass distributions. Dusty galaxies uncovered in submillimeter surveys are particularly useful in this regard because of the large volume probed by these surveys. Previous discoveries of strong galaxy─galaxy lensed dusty galaxies are predominantly the brightest in the sky discovered by Herschel, South Pole Telescope, and Planck. However, models have also predicted a nonnegligible fraction of strong galaxy─galaxy lensed faint dusty galaxies, which were difficult to confirm due to technical difficulties. Utilizing the deepest SCUBA-2 submillimeter survey, STUDIES, in both the COSMOS and the Ultra Deep Survey fields, together with a red JWST color selection method, we discover a population of 13 strong galaxy─galaxy lensed faint dusty galaxies. The rich ancillary data allow us to confirm their strongly lensed nature via estimates of redshifts and lens modeling. Our systematic search has allowed us to construct the 450 μm number counts of strongly lensed sources down to the flux levels about an order of magnitude fainter than previous measurements. The measured lensing fractions of ∼1% are consistent with predictions from models that also successfully produce the number density of the strong galaxy─galaxy lensed bright dusty galaxies. Future searches from Euclid and Roman are expected to discover orders of magnitude more strongly lensed faint dusty galaxies.

Keywords: Strong gravitational lensing, Far infrared astronomy, James Webb Space Telescope, Infrared galaxies, Galaxy evolution, Submillimeter astronomy
Solar Flare Ion Temperatures. This Letter proposes that the ion temperature is several times the local electron temperature in the hot onset phase and in the above-the-loop region of solar flares. The Letter considers: the evidence of spectral line Doppler widths ("nonthermal" broadening); evidence for "universal" ion and electron temperature increase scaling relations for magnetic reconnection in the solar wind, Earth's magnetopause, Earth's magnetotail, and numerical simulations; and thermal equilibration times for onset and above-the-loop densities, which are much longer than previous estimates based on soft X-ray flare loops. We conclude that the ion temperature is likely to reach 60 MK or greater and that it may represent a substantial part of spectral line widths, significantly contributing to solving the long-standing issue of the excess nonthermal broadening in flare lines.

Keywords: Solar flares, Solar magnetic reconnection, Solar flare spectra, Stellar flares, Spectroscopy
High Resolution ALMA Data of the Fomalhaut Debris Disk Confirms Apsidal Width Variation. We present long-baseline observations of the Fomalhaut outer debris disk at 223 GHz (1.3 mm) from Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 5, which we use along with archival short-baseline observations to produce a 0 .″ 57 resolution mosaic of the disk at a sensitivity of 7 μJy bm−1. We use radial profiles to measure the disk at the ansae and find that the southeast (SE) side of the disk is 4 au wider than the northwest (NW) side as observed by ALMA. We also find that the peak brightness of the NW ansa is 21% ± 1% brighter than the SE ansa. We perform Markov Chain Monte Carlo fits of the ALMA visibilities using two analytical, eccentric disk models. Our results suggest that the model including a dispersion parameter for the proper eccentricity ( σep ), which accounts for additional scatter in the eccentricity of individual orbits, is preferred over the model without one. Such a model implies that self-gravitation, particle collisions, and close-packing could play a role in shaping the overall structure of the Fomalhaut disk, as is seen in eccentric planetary rings. Crucially, neither model can reproduce the brightness or width asymmetry near the NW ansa. No emission from the intermediate belt is detected, allowing us to place a 3σ upper limit of 396 μJy at 1.3 mm. We also discover a spectral line in archival Cycle 3 data centered at νobs ≍ 230.25 GHz at the location of the "Great Dust Cloud," whose redshift from the expected CO line for Fomalhaut confirms the source is a background galaxy.

Keywords: Debris disks, Planet formation
Ubiquitous Occurrences of Multiscale Layers of Magnetic Reconnection across a Solar Wind Stream Interaction Region at 1 au. We present a first record of significantly enhanced occurrences of magnetic reconnection exhausts as measured by the Wind satellite across a stream interaction region (SIR) at 1 au from 2019 January 4 10:11:20 UT to 2019 January 5 09:58:00 UT. The activity is clustered in a slow wind compression regime ahead of the SIR interface with a deflected, compressed fast wind. The 43 exhausts of this 1 day SIR dominate a distribution of 71 exhausts as obtained by a multiwindow sliding technique application to the 8 day period on 2019 January 1–9. Active current sheets inside the SIR are associated with normal directions mostly near the ecliptic plane and a more azimuthal-than-Parker magnetic field direction at 1 au. We find that exhausts wider than 500 ion inertial lengths are typically present just upstream and inside this SIR rather than within unperturbed slow and fast winds beyond a shocked solar wind. The observations suggest that plasma and field compressions may be crucial elements in driving a breakup of large-scale current sheets embedded in SIRs into smaller, multilayered current sheet segments through magnetic reconnection.

Keywords: Corotating streams, Interplanetary magnetic fields, Solar magnetic reconnection
VLT/MUSE Detection of the AB Aurigae b Protoplanet with H<SUB>α</SUB> Spectroscopy. We analyze high-contrast, medium-spectral-resolution Hα observations of the star AB Aurigae using the Very Large Telescope's Multi Unit Spectroscopic Explorer (MUSE). In multiple epochs, MUSE detects the AB Aur b protoplanet discovered from Subaru/SCExAO data in emission at wavelengths slightly blueshifted from the Hα line center (i.e., at 6558.88─6560.13Å; ∼−100 km s−1) and in absorption at redshifted wavelengths (6562.8─6565.1Å; ∼75 km s−1). AB Aur b's Hα spectrum is inconsistent with that of the host star or the average residual disk spectrum and is dissimilar to that of PDS 70 b and c. Instead, the spectrum's shape resembles that of an inverse P Cygni profile seen in some accreting T Tauri stars and interpreted as evidence of infalling cold gas from accretion, although we cannot formally rule out all other nonaccretion origins for AB Aur b's MUSE detection. AB Aurigae hosts only the second protoplanetary system detected in Hα thus far and the first with a source showing a spectrum resembling an inverse P Cygni profile. Future modeling and new optical data will be needed to assess how much AB Aur b's emission source(s) originates from protoplanet accretion reprocessed by the disk, a localized scattered-light feature with a unique Hα profile, or another mechanism.

Keywords: Exoplanet formation, High contrast spectroscopy, Protoplanetary disks, Planet formation
Mineral Cloud Formation above Magma Oceans in Sub-Neptune Atmospheres. The potential presence of a magma surface below a thick atmosphere primarily composed of hydrogen in some sub-Neptune exoplanets suggests a strong link between the interior composition and atmosphere through chemical coupling of volatile and refractory species. In this study, we aim to model the possibility for mineral cloud formation in the atmosphere of sub-Neptunes from outgassing of refractory species at the magma surface. In our specific cases, we find that mineral clouds easily form near the magma–atmosphere boundary, but also higher in the atmosphere once vapour is mixed with the cooler atmospheric regions. We find that the vertical cloud structure depends on the mixing profile of the atmosphere, with stronger mixing allowing particles to remain lofted in the atmosphere, while weak to moderate mixing produces larger, more sedimented cloud particle profiles. We suggest that, due to the strong thermal feedback from cloud opacity, clouds may play an important role in the overall structure of the interior–surface–atmosphere coupled system in sub-Neptunes, as well as affect their observed spectral properties, especially at near-infrared wavelengths.

Keywords: Exoplanet structure, Mini Neptunes, Exoplanet atmospheres, Exoplanets
The Near-infrared Echo from SN 2023xgo: Evidence for a Massive Presupernova Eruption in a Type Ibn/Icn Supernova. We present near-infrared (NIR) and optical observations and analysis of the Type Ibn/Icn supernova (SN) 2023xgo, spanning the period from 2 to 100 days past explosion. A comparison of the NIR light curves and color evolution with those of other Type Ibn SNe reveals prominent NIR excess persisting from 15 to 100 days. The spectral energy distribution is well explained by a combination of a hot blackbody component and a carbon dust model. The dust temperature remained relatively constant at T = 1600 ± 100 K up to t = 60 days. The estimated dust mass is ∼1.2 × 10‑4 M⊙. Based on the SN emission of 1042 erg s‑1 at peak luminosity, the evaporation radius is estimated to be 1.2 × 1016 cm, consistent with the expectation from light travel time. The dust shell is located outside the shocked, cool dense shell at the position of 7.6 × 1014 cm. It suggests that the observed NIR excess originates from preexisting circumstellar (CS) dust. Considering a typical dust-to-gas mass ratio, the CS gas mass is estimated to be ≃10‑2 M⊙, implying a high mass-loss rate of ∼0.1 M⊙yr‑1 from either a low-mass helium star progenitor with a binary interaction, or maybe a massive Wolf–Rayet star that experienced a significant eruption.

Keywords: Circumstellar matter, Circumstellar dust, Supernovae, Core-collapse supernovae
Refitting Cosmological Data with Neutrino Mass and Degeneracy. A simple and natural extension of the standard Lambda cold dark matter (ΛCDM) model is to allow relic neutrinos to have finite chemical potentials. We confront this ΛCDMξ model, a ΛCDM with neutrino mass Mν and degeneracy ξ3 as additional parameters, with various cosmological data sets. We find that the H0 and S8 tensions become significant only in the presence of the cosmic microwave background (CMB) polarization data. Specifically, the global and local measurements agree to within 0.8σ and 1.6σ for the H0 and S8 tensions, respectively, when the CMB polarization data are not included. Therefore, the H0 and S8 tensions exist between CMB temperature and polarization data, both being global measurements. Fitting the ΛCDMξ model to the CMB temperature data, we find 3σ evidence for nonzero neutrino mass ( Mν=0.57‑0.13+0.17eV ) and degeneracy ( ξ3=1.13‑0.19+0.41 ), and the  O(1)  neutrino degeneracy parameter is compatible with Big Bang nucleosynthesis data. The scalar index ns exceeds 1 slightly, which is compatible with some hybrid inflation models. Furthermore, the recent DESI baryon acoustic oscillation data prefer the ΛCDMξ model to the Planck ΛCDM model. Similar results are obtained when including additional supernova data, while the inclusion of the Atacama Cosmology Telescope τ prior shifts the preferred Mν and ξ3 values closer to zero and brings ns back to the values favored when the polarization data are included.

Keywords: Cosmic microwave background radiation, Cosmological neutrinos, Cosmological parameters