Sazuna/UAT_keywords huggingface dataset:
Submillimeter-wavelength Polarimetry of IRC+10216. We present SCUBA-2/POL-2 850 μm polarimetric observations of the circumstellar envelope (CSE) of the carbon-rich asymptotic giant branch (AGB) star IRC+10216. Both far-IR (FIR) and optical polarization data indicate grains aligned with their long axis in the radial direction relative to the central star. The 850 μm polarization does not show this simple structure. The 850 μm data are indicative, albeit not conclusive, of a magnetic dipole geometry. Assuming such a simple dipole geometry, the resulting 850 μm polarization geometry is consistent with both Zeeman observations and small-scale structure in the CSE. While there is significant spectral-line polarization contained within the SCUBA-2 850 μm passband for the source, it is unlikely that our broadband polarization results are dominated by line polarization. To explain the required grain alignment, grain mineralogy effects, due to either fossil silicate grains from the earlier oxygen-rich AGB phase of the star or due to the incorporation of ferromagnetic inclusions in the largest grains, may play a role. We argue that the most likely explanation is due to a new alignment mechanism wherein a charged grain, moving relative to the magnetic field, precesses around the induced electric field and therefore aligns with the magnetic field. This mechanism is particularly attractive as the optical, FIR, and submillimeter-wave polarization of the carbon dust can then be explained in a consistent way, differing simply due to the charge state of the grains.

Keywords: Circumstellar dust, Magnetic fields, Carbonaceous grains, Asymptotic giant branch stars
Investigation of Nulling and Subpulse-drifting Properties of PSR J1649+2533 with FAST. We report the nulling and subpulse-drifting properties of PSR J1649+2533 with observations of the Five-hundred-meter Aperture Spherical Radio Telescope (FAST). The FAST observations reveal that the nulling fraction of this pulsar is about 20.9% ± 0.8% at 1250 MHz. The statistical study of the durations of the nulling and burst states shows that the burst states can persist for extended pulse periods, exceeding 100 periods in some cases, while the shortest lasts only a few pulse periods. The null states have a much shorter duration, with a maximum duration of less than 30 pulse periods. A comparative study between the pulse profiles of the first active pulse (FAP) and the last active pulse (LAP) shows that the pulse profiles of LAPs are stronger and wider than those of FAPs. An analysis of the two-dimensional fluctuation spectrum for the single-pulse stack indicates that the pulsar exhibits clear amplitude modulation and subpulse drifting. The periods are a P 3 = 2.5 ± 0.1 spin period and P 2 = 17.°0 ± 0.°5 at 1250 MHz, respectively. In addition, the multiband investigation shows that P 2 seems to increase with the increase of the observing frequency, i.e., P 2 ∝ ν 0.8±0.1. This seems to be caused by the increasing pulse-profile width with the frequency. The high-sensitivity FAST observations will enable a detailed understanding of the emission of this pulsar and provide important clues for theoretical studies of the radiation mechanism.

Keywords: Neutron stars, Non-thermal radiation sources, Pulsars, Radio pulsars
Resolving the Periods of the Asynchronous Polar 1RXS J083842.1─282723. 1RXS J083842.1−282723 is a nearly synchronous magnetic cataclysmic variable with a simple X-ray light curve. While its orbital period was fairly well established at P orb = 98.4 minutes from optical spectroscopy, indirect estimates of P spin/P orb ranged from 0.90 to 0.96 because the short X-ray light curves could not determine the beat period to a factor of 2. We analyze a recent 50 days TESS observation, and ground-based optical time-series photometry spanning 9 yr, that together measure precise beat, orbit, and spin periods and enable the X-ray and optical modulations to be phase aligned. Although the X-ray light curves do not distinguish between a beat period of 16.11 or 32.22 hr, all of the optical evidence favors the longer value, with complete pole switching of accretion every half beat cycle. This would require P spin/P orb = 0.952. Long-term optical monitoring also shows a decline in accretion rate, and a change in the beat-folded light curve. It would be useful to obtain a new X-ray/optical observation of at least 32 hr duration to examine any associated change in accretion structure, and to confirm the spin and beat periods.

Keywords: DQ Herculis stars, Cataclysmic variable stars, AM Herculis stars
Solar Spicules, Filigrees, and Solar Wind Switchbacks. Spicules, the smallest observable jetlike dynamic features ubiquitous in the chromosphere, are supposedly an important potential source for small-scale solar wind transients, with supporting evidence yet needed. We studied the high-resolution Hα images (0.″10) and magnetograms (0.″29) from the Big Bear Solar Observatory to find that spicules are an ideal candidate for the solar wind magnetic switchbacks detected by the Parker Solar Probe (PSP). It is not that spicules are a miniature of coronal jets, but that they have unique properties not found in other solar candidates in explaining solar origin of switchbacks. (1) The spicules under this study originate from filigrees, all in a single magnetic polarity. Since filigrees are known as footpoints of open fields, the spicule guiding field lines can form a unipolar funnel, which is needed to create an SB patch, a group of field lines that switch from one common base polarity to the other polarity. (2) The spicules come in a cluster lined up along a supergranulation boundary, and the simulated waiting times from their spatial intervals exhibit a number distribution continuously decreasing from a few seconds to ∼30 minutes, similar to that of switchbacks. (3) From a time–distance map for spicules, we estimate their occurrence rate as 0.55 spicules Mm‑2 s‑1, which is sufficiently high for detection by PSP. In addition, the dissimilarity of spicules with coronal jets, including the absence of base brightening and low correlation with EUV emission, is briefly discussed.

Keywords: Solar wind, Solar chromosphere, Solar magnetic fields
On the Formation of Double Neutron Stars in the Milky Way: Influence of Key Parameters. The detection of gravitational wave events has stimulated theoretical modeling of the formation and evolution of double compact objects (DCOs). However, even for the most studied isolated binary evolution channel, there exist large uncertainties in the input parameters and treatments of the binary evolution process. So far, double neutron stars (DNSs) are the only DCOs for which direct observations are available through traditional electromagnetic astronomy. In this work, we adopt a population synthesis method to investigate the formation and evolution of Galactic DNSs. We construct 324 models for the formation of Galactic DNSs, taking into account various possible combinations of critical input parameters and processes such as mass transfer efficiency, supernova type, common envelope efficiency, neutron star kick velocity, and pulsar selection effect. We employ Bayesian analysis to evaluate the adopted models by comparing with observations. We also compare the expected DNS merger rate in the galaxy with that inferred from the known Galactic population of pulsar-neutron star systems. Based on these analyses we derive the favorable range of the aforementioned key parameters.

Keywords: Neutron stars, Stellar evolution, Binary stars, Pulsars
The Effect of Ultraviolet Photon Pumping of H<SUB>2</SUB> in Dust-deficient Protoplanetary Disks. We perform radiation hydrodynamics simulations to study the structure and evolution of a photoevaporating protoplanetary disk. Ultraviolet and X-ray radiation from the host star heats the disk surface, where H2 pumping also operates efficiently. We run a set of simulations in which we varied the number of dust grains or the dust-to-gas mass ratio, which determines the relative importance between photoelectric heating and H2 pumping. We show that H2 pumping and X-ray heating contribute more strongly to the mass loss of the disk when the dust-to-gas mass ratio is ${ \mathcal D }\leqslant {10}^{-3}$ . The disk mass-loss rate decreases with a lower dust amount, but remains around 10‑10‑11 M ⊙yr‑1. In these dust-deficient disks, H2 pumping enhances photoevaporation from the inner disk region and shapes the disk mass-loss profile. We thus argue that the late-stage disk evolution is affected by the ultraviolet H2 pumping effect. The mass-loss rates derived from our simulations can be used in the study of long-term disk evolution.

Keywords: Hydrodynamical simulations, Star formation, Protoplanetary disks, Interstellar medium, Planet formation
The Alpha-proton Differential Flow in the Alfvénic Young Solar Wind: from Sub-Alfvénic to Super-Alfvénic. Data obtained from Parker Solar Probe (PSP) since 2021 April have shown the first in situ observation of the solar corona, where the solar wind is formed and accelerated. Here, we investigate the alpha-proton differential flow and its characteristics across the critical Alfvén surface (CAS) using data from PSP during encounters 8–10 and 12–13. We first show the positive correlation between the alpha-proton differential velocity and the bulk solar wind speed at PSP encounter distances. Then we explore how the characteristics of the differential flow vary across the CAS and how they are affected by Alfvénic fluctuations including switchbacks. We find that the differential velocity below the CAS is generally smaller than that above the CAS, and the local Alfvén speed well limits the differential speed both above and below the CAS. The deviations from the alignment between the differential velocity and the local magnetic field vector are accompanied by large-amplitude Alfvénic fluctuations and decreases in the differential speed. Moreover, we observe that V  α p  increases from M  A  &lt; 1 to M  A  ≃ 2 and then starts to decrease, which suggests that alphas may remain preferentially accelerated well above the CAS. Our results also reveal that in the sub-Alfvénic solar wind both protons and alphas show a strong correlation between their velocity fluctuations and magnetic field fluctuations, with a weaker correlation for alphas. By contrast, in the super-Alfvénic regime the correlation remains high for protons, but is reduced for alphas.

Keywords: Space plasmas, Solar physics, Solar wind, Alfven waves
The Mira Distance to M101 and a 4% Measurement of H <SUB>0</SUB>. The giant spiral galaxy M101 is host to the nearest recent Type Ia supernova (SN 2011fe) and thus has been extensively monitored in the near-infrared to study the late-time light curve of the SN. Leveraging this existing baseline of observations, we derive the first Mira-based distance to M101 by discovering and classifying a sample of 211 Miras with periods ranging from 240–400 days in the SN field. Combined with new Hubble Space Telescope (HST) WFC3/IR channel observations, our data set totals 11 epochs of F110W (HST YJ) and 13 epochs of F160W (HST H) data spanning ∼2900 days. We adopt absolute calibrations of the Mira period–luminosity relation based on geometric distances to the Large Magellanic Cloud and the water megamaser host galaxy NGC 4258, and find μ M101 = 29.10 ± 0.06 mag. This distance is in 1σ agreement with most other recent Cepheid and tip of the red giant branch distance measurements to M101. Including the previous Mira SN Ia host, NGC 1559, and SN 2005df, we determine the fiducial SN Ia peak luminosity, ${M}_{B}^{0}=-19.27\,\pm \,0.09$ mag. With the Hubble diagram of supernovae Ia, we derive H 0 = 72.37 ± 2.97 km s‑1 Mpc‑1, a 4.1% measurement of H 0 using Miras. We find excellent agreement with recent Cepheid distance ladder measurements of H 0 and confirm previous indications that the local universe value of H 0 is higher than the early universe value at ∼95% confidence. Currently, the Mira-based H 0 measurement is still dominated by the statistical uncertainty in the SN Ia peak magnitude.

Keywords: Galaxy distances, Observational cosmology, Distance indicators, Hubble constant, Asymptotic giant branch stars, Mira variable stars, Type Ia supernovae, Stellar distance
The Mass of the Large Magellanic Cloud from the Three-dimensional Kinematics of Its Globular Clusters. We estimate the mass of the Large Magellanic Cloud (LMC) using the kinematics of 30 LMC globular clusters (GCs). We combine proper motions measured with the Hubble Space Telescope, Gaia, or a combination of the two, from a recent study by Bennet et al. with literature line-of-sight velocities (LOSVs) to give three components of motion. With these, we derive a 3D velocity dispersion anisotropy $\beta =-{0.72}_{-1.07}^{+0.62}$ , consistent with the GCs forming a flattened system with significant azimuthal motion. We then apply a tracer mass estimator and measure an enclosed mass $M(\lt 13.2\,\mathrm{kpc})={2.66}_{-0.36}^{+0.42}\times {10}^{10}$ M ⊙. This is broadly consistent with results from previous studies of the LOSVs of GCs and other luminous tracers. Assuming a cosmologically constrained Navarro–Frenk–White distribution for the dark matter, this implies a virial mass ${M}_{\mathrm{virial}}={1.80}_{-0.54}^{+1.05}\times {10}^{11}$ M ⊙. Despite being an extrapolation by almost an order of magnitude in radius, this result is consistent with published estimates from other methods that are directly sensitive to the LMC's total mass. Our results support the conclusion that the LMC is approximately ${17}_{-6}^{+10}$ % of the Milky Way's mass, making it a significant contributor to the Local Group potential.

Keywords: Galaxy dynamics, Large Magellanic Cloud, Galaxy mass distribution, Galaxy kinematics, Galaxy masses
Direct In Situ Measurements of a Fast Coronal Mass Ejection and Associated Structures in the Corona. We report on the first direct in situ measurements of a fast coronal mass ejection (CME) and shock in the corona, which occurred on 2022 September 5. In situ measurements from the Parker Solar Probe spacecraft near perihelion suggest two shocks, with the second one decayed, which is consistent with more than one eruption in coronagraph images. Despite a flank crossing, the measurements indicate unique features of the young ejecta: a plasma much hotter than the ambient medium, suggestive of a hot solar source, and a large plasma β implying a highly non-force-free state and the importance of thermal pressure gradient for CME acceleration and expansion. Reconstruction of the global coronal magnetic fields shows a long-duration change in the heliospheric current sheet (HCS), and the observed field polarity reversals agree with a more warped HCS configuration. Reconnection signatures are observed inside an HCS crossing as deep as the sonic critical point. As the reconnection occurs in the sub-Alfvénic wind, the reconnected flux sunward of the reconnection site can close back to the Sun, which helps balance magnetic flux in the heliosphere. The nature of the sub-Alfvénic wind after the HCS crossing as a low Mach-number boundary layer (LMBL) leads to in situ measurements of the near subsonic plasma at a surprisingly large distance. Specifically, an LMBL may provide favorable conditions for the crossings of the sonic critical point in addition to the Alfvén surface.

Keywords: Solar magnetic reconnection, Solar wind, Solar corona, Solar coronal mass ejections, Shocks
On the Existence, Rareness, and Uniqueness of Quenched H I-rich Galaxies in the Local Universe. Using data from ALFALFA, xGASS, H I-MaNGA, and the Sloan Digital Sky Survey (SDSS), we identify a sample of 47 "red but H I-rich" (RR) galaxies with near-UV (NUV) ‑ r &gt; 5 and unusually high H I-to-stellar mass ratios. We compare the optical properties and local environments between the RR galaxies and a control sample of "red and H I-normal" (RN) galaxies that are matched in stellar mass and color. The two samples are similar in the optical properties typical of massive red (quenched) galaxies in the local Universe. The RR sample tends to be associated with slightly lower-density environments and has lower clustering amplitudes and smaller neighbor counts at scales from several hundred kiloparsecs to a few megaparsecs. The results are consistent with the RR galaxies being preferentially located at the center of low-mass halos, with a median halo mass ∼1012 h ‑1 M ⊙ compared to ∼1012.5 h ‑1 M ⊙ for the RN sample. This result is confirmed by the SDSS group catalog, which reveals a central fraction of 89% for the RR sample, compared to ∼60% for the RN sample. If assumed to follow the H I size–mass relation of normal galaxies, the RR galaxies have an average H I-to-optical radius ratio of R HI/R 90 ∼ 4, four times the average ratio for the RN sample. We compare our RR sample with similar samples in previous studies, and quantify the population of RR galaxies using the SDSS complete sample. We conclude that the RR galaxies form a unique but rare population, accounting for only a small fraction of the massive quiescent galaxy population. We discuss the formation scenarios of the RR galaxies.

Keywords: Galaxy dark matter halos, Interstellar atomic gas, Cold dark matter, Neutral hydrogen clouds, Cold neutral medium, Interstellar clouds
Complex K: Supernova Origin of Anomalous-velocity H I Structure. We address one of the lingering mysteries of high-velocity clouds: If the anomalous negative velocities are the result of the approaching gas from old supernovae, then where are the receding counterparts of the expanding shells? Data from the λ-21 cm Galactic neutral hydrogen EBHIS survey (Winkel et al.) show multiple signatures of the expanding shells. The near-side (approaching) H I shells form part of Complex K. The high blueshifted velocities result from the H I moving into the low-density environment of inter-arm space. The H I data also show a distinctive, bow-shaped feature, the signature of the far-side (receding) emission of an expanding shell. The low redshifted velocity results from the gas expanding into volumes of space with a higher density. If we make the simplifying assumptions that the expansion of the shells is uniform and spherically symmetric, then the explosions took place about ⪅3 × 105 yr ago. The momentum, p ∼ 7 × 104 M ⊙ km s‑1, agrees with recent model estimates for supernova evolution. Supernova explosions attributed to the unseen companion in several binary systems identified by the Third Gaia Data Release may be responsible for anomalous-velocity H I gas in Complex K. Four binary star systems with neutron-star candidates are located at the edge of the Sagittarius spiral arm and used to determine the distance to the H I features discussed here.

Keywords: Interstellar clouds
Detection of Extragalactic Anomalous Microwave Emission in NGC 2903 Using KVN Single-dish Observations. We present the results of the single-dish observations using the Korean VLBI Network to search for anomalous microwave emission (AME) in nearby galaxies. The targets were selected from 'Mapping the dense molecular gas in the strongest star-forming galaxies' (MALATANG), a legacy survey project of the James Clerk Maxwell Telescope. The MALATANG galaxies are good representatives of local galaxies with enhanced nuclear activity associated with star formation and/or active galactic nuclei (AGNs), providing IR-bright galaxy samples; thus, they are good candidates for AME hosts. Combining with ancillary data, we investigated the radio–IR spectral energy distribution (SED), while searching for AME signals in five galaxies. The AME in NGC 2903 was well detected at a significant confidence level, whereas that in NGC 2146 and M82 was marginal. NGC 1068 and Arp 299 indicated no significant hints, and we provide upper limits for the AME. The best-fit SED exhibited local peaks of the AME components at higher frequencies and with stronger peak fluxes than those in previous studies. This suggested that AME originates from denser environments such as molecular clouds or photodissociation regions rather than warm neutral/ionized medium as commonly suggested by previous studies. Further, our AME-detected targets were observed to exhibit higher specific star formation rates than the other extragalactic AME hosts. Furthermore, AME favored starburst galaxies among our sample rather than AGN hosts. Consequently, this might imply that AGNs are excessively harsh environments for tiny dust to survive.

Keywords: Interstellar dust, Spectral energy distribution, Infrared excess galaxies, Very small grains
A Comprehensive Investigation of Gamma-Ray Burst Afterglows Detected by TESS. Gamma-ray bursts produce afterglows that can be observed across the electromagnetic spectrum and can provide insight into the nature of their progenitors. While most telescopes that observe afterglows are designed to rapidly react to trigger information, the Transiting Exoplanet Survey Satellite (TESS) continuously monitors sections of the sky at cadences between 30 minutes and 200 s. This provides TESS with the capability of serendipitously observing the optical afterglow of GRBs. We conduct the first extensive search for afterglows of known GRBs in archival TESS data reduced with the TESSreduce package, and detect 11 candidate signals that are temporally coincident with reported burst times. We classify three of these as high-likelihood GRB afterglows previously unknown to have been detected by TESS, one of which has no other afterglow detection reported on the Gamma-ray Coordinates Network. We classify five candidates as tentative and the remainder as unlikely. Using the afterglowpy package, we model each of the candidate light curves with a Gaussian and a top-hat model to estimate burst parameters; we find that a mean time delay of 740 ± 690 s between the explosion and afterglow onset is required to perform these fits. The high cadence and large field of view make TESS a powerful instrument for localising GRBs, with the potential to observe afterglows in cases when no other backup photometry is possible, and at timescales previously unreachable by optical telescopes.

Keywords: Gamma-ray bursts, Transient sources, High energy astrophysics
Dust and Volatiles in the Disintegrating Comet C/2019 Y4 (ATLAS). C/2019 Y4 (ATLAS) is an Oort cloud comet with an orbital period of ∼5895 yr. Starting in 2020 March, its nucleus underwent disintegration. In order to investigate the gas and dust properties of C/2019 Y4 (ATLAS) during its disintegration, we obtained long-slit spectra at 3600–8700 Å and BVRI multiband images with the Xinglong 2.16 m Telescope in 2020 April. Our observations revealed that C/2019 Y4 (ATLAS) exhibited strong emission bands of CN, C2, C3, and NH2, which are superimposed on a dust-scattering continuum, typical of cometary spectra in the optical. The production rates of CN, C2, and C3 derived using the Haser model and the corresponding C2/CN and C3/CN ratios suggest that C/2019 Y4 (ATLAS) is a "typical" Oort cloud comet under the A'Hearn classification, although it appears less dusty, as revealed by the Af ρ quantities. Its dust-scattering reflectivity is slightly red, with a gradient of ∼5% per 103Å. We model the reflectivity gradient in terms of porous dust and find that the red color is accounted for by porous dust.

Keywords: Long period comets, Comets, Small Solar System bodies