Sazuna/UAT_keywords huggingface dataset:
ForSE: A GAN-based Algorithm for Extending CMB Foreground Models to Subdegree Angular Scales. We present FORSE (Foreground Scale Extender), a novel Python package that aims to overcome the current limitations in the simulation of diffuse Galactic radiation, in the context of cosmic microwave background (CMB) experiments. FORSE exploits the ability of generative adversarial neural networks (GANs) to learn and reproduce complex features present in a set of images, with the goal of simulating realistic and non-Gaussian foreground radiation at subdegree angular scales. This is of great importance in order to estimate the foreground contamination to lensing reconstruction, delensing, and primordial B-modes for future CMB experiments. We applied this algorithm to Galactic thermal dust emission in both total intensity and polarization. Our results show how FORSE is able to generate small-scale features (at 12') having as input the large-scale ones (80'). The injected structures have statistical properties, evaluated by means of the Minkowski functionals, in good agreement with those of the real sky and which show the correct amplitude scaling as a function of the angular dimension. The obtained thermal dust Stokes Q and U full-sky maps as well as the FORSE package are publicly available for download.

Keywords: Diffuse radiation, Cosmic microwave background radiation, Neural networks
GRB 191016A: A Long Gamma-Ray Burst Detected by TESS. The Transiting Exoplanet Survey Satellite (TESS) exoplanet-hunting mission detected the rising and decaying optical afterglow of GRB 191016A, a long gamma-ray burst (GRB) detected by Swift-BAT but without prompt XRT or UVOT follow-up due to proximity to the Moon. The afterglow has a late peak at least 1000 s after the BAT trigger, with a brightest-detected TESS data point at 2589.7 s post-trigger. The burst was not detected by Fermi-LAT, but was detected by Fermi-GBM without triggering, possibly due to the gradual nature of the rising light curve. Using ground-based photometry, we estimate a photometric redshift of zphot = 3.29 ± 0.40. Combined with the high-energy emission and optical peak time derived from TESS, estimates of the bulk Lorentz factor ΓBL range from 90 to 133. The burst is relatively bright, with a peak optical magnitude in ground-based follow-up of R = 15.1 mag. Using published distributions of GRB afterglows and considering the TESS sensitivity and sampling, we estimate that TESS is likely to detect ∼1 GRB afterglow per year above its magnitude limit.

Keywords: Gamma-ray bursts, Sky surveys, Transient detection
Measuring the Gravitomagnetic Distortion from Rotating Halos. I. Methods. Source galaxy images are distorted not only by a static gravitational potential, but also by frame-dragging induced by massive rotating objects like clusters of galaxies. Such an effect is well understood theoretically; it is therefore of great interest to estimate its detectability for future surveys. In this work, we analyze the lensing convergence κ around rotating dark matter halos. The rotation of the massive objects generates a gravitomagnetic potential giving rise to an anisotropic contribution to the lensing potential. We construct an estimator δκ to describe the difference between the symmetric enhancement and reduction of κ around the halo rotation axis, finding that it is well approximated by a function proportional to the halo velocity dispersion squared times a dimensionless angular momentum parameter. Using simulation mocks with realistic noise level for a survey like the Legacy Survey of Space and Time (LSST), we test our estimator, and show that the signal from frame-dragging of stacked rotating lenses is consistent with zero within 1σ. However, we find that the most massive cluster in SDSS DR7 spectroscopic selected group catalog has a line-of-sight rotation velocity of 195.0 km s-1 and velocity dispersion of 667.8 km s-1, which is at 1.2 × 10-8 odds according to the angular momentum probability distribution inferred from N-body simulations. By studying SDSS DR7 spectroscopic selected group catalog, we show how rotating clusters can be identified, and, finding that fast rotating clusters might be more abundant than in estimates based on simulations, a detection of gravitomagnetic distortion may be at reach in future surveys.

Keywords: Galaxy clusters, General relativity
PINT: A Modern Software Package for Pulsar Timing. Over the past few decades, the measurement precision of some pulsar timing experiments has advanced from ∼10 μs to ∼10 ns, revealing many subtle phenomena. Such high precision demands both careful data handling and sophisticated timing models to avoid systematic error. To achieve these goals, we present PINT (PINT Is Not TEMPO3), a high-precision Python pulsar timing data analysis package, which is hosted on GitHub and available on the Python Package Index (PyPI) as pint-pulsar. PINT is well tested, validated, object oriented, and modular, enabling interactive data analysis and providing an extensible and flexible development platform for timing applications. It utilizes well-debugged public Python packages (e.g., the NUMPY and ASTROPY libraries) and modern software development schemes (e.g., version control and efficient development with git and GitHub) and a continually expanding test suite for improved reliability, accuracy, and reproducibility. PINT is developed and implemented without referring to, copying, or transcribing the code from other traditional pulsar timing software packages (e.g., TEMPO/TEMPO2) and therefore provides a robust tool for cross-checking timing analyses and simulating pulse arrival times. In this paper, we describe the design, use, and validation of PINT, and we compare timing results between it and TEMPO and TEMPO2.

Keywords: Astronomy software, Pulsar timing method, Millisecond pulsars, Pulsars, Radio pulsars
Accelerated Galaxy Growth and Environmental Quenching in a Protocluster at z = 3.24. We present a multiwavelength study of galaxies around D4UD01, a spectroscopically confirmed protocluster at z = 3.24, to investigate environmental trends. 450 galaxies are selected based on KS band detection with photometric redshifts (photo-z) at 3.0 &lt; z &lt; 3.4, among which ∼12% are classified as quiescent galaxies. The quiescent galaxies are among the most massive and reddest ones in the entire sample. We identify a large photo-z galaxy overdensity in the field, which lies close to the previously spectroscopically confirmed sources of the protocluster. We find that the quiescent galaxies are largely concentrated in the overdense protocluster region with a higher quiescent fraction, showing a sign of environmental quenching. Galaxies in the protocluster are forming faster than their field counterparts as seen in the stellar mass function, suggesting early and accelerated mass assembly in the overdense regions. Although weak evidence of suppressed star formation is found in the protocluster, the statistics are not significant enough to draw a definite conclusion. Our work sheds light on how the formation of massive galaxies is affected in the dense region of a protocluster when the universe was only 2 Gyr old.

Keywords: Protoclusters
Condensation of Glass with Multimetal Nanoparticles: Implications for the Formation Process of GEMS Grains. Interplanetary dust particles contain grains of glass with embedded metals and sulfides (GEMS; i.e., amorphous silicate grains with diameters of a few hundred nanometers containing Fe nanoinclusions and Fe sulfide particles), which are considered to be among the building blocks of the solar system. To explore that GEMS grains formed during the condensation process, condensation experiments were carried out in Si-Mg-Fe-Al-Ca-Ni-O and Mg-Si-Fe-Ca-Al-Na-O systems using an induction thermal plasma furnace. In all experimental runs, spherical grains (mostly composed of amorphous silicate) with diameter &lt;100 nm formed. The analysis of the amorphous silicates, which were classified as Mg rich or Si rich, indicated that the condensates formed via melting. Fe led to the formation of fine magnetite grains in most of the oxidative experiments, to 10 nm metal grains (i.e., kamacite and taenite) under intermediate redox conditions, and to 30-100 nm Fe silicide grains (i.e., gupeiite, xifengite, and fersilicite) in most of the reductive experiments. Under intermediate redox conditions, some amorphous silicate particles showed multiple Fe inclusions with textures very similar to those of GEMS grains except for FeS, indicating that GEMS could form via melt condensation of high-temperature gases. Considering the nucleation and growth of solids from high-temperature gas during cooling, we infer that GEMS grains form either in the local environment of a protosolar disk (and be related to chondrule formations) or around evolved stars related to Type II-P supernovae and asymptotic giant branch-type stars.

Keywords: Interplanetary dust, Laboratory astrophysics, Silicate grains
ANTARES Search for Point Sources of Neutrinos Using Astrophysical Catalogs: A Likelihood Analysis. A search for astrophysical pointlike neutrino sources using the data collected by the ANTARES detector between 2007 January 29 and 2017 December 31 is presented. A likelihood method is used to assess the significance of an excess of muon neutrinos inducing track-like events in correlation with the location of a list of possible sources. Different sets of objects are tested in the analysis: (a) a subsample of the Fermi 3LAC catalog of blazars, (b) a jet-obscured population of active galactic nuclei, (c) a sample of hard X-ray selected radio galaxies, (d) a star-forming galaxy catalog, and (e) a public sample of 56 very-high-energy track events from the IceCube experiment. None of the tested sources shows a significant association with the sample of neutrinos detected by ANTARES. The smallest p-value is obtained for the catalog of radio galaxies with an equal-weights hypothesis, with a pre-trial p-value equivalent to a 2.8σ excess, which is equivalent to 1.6σ post-trial. In addition, the results of a dedicated analysis for the blazar MG3 J225517+2409 are also reported: this source is found to be the most significant within the Fermi 3LAC sample, with five ANTARES events located less than one degree from the source. This blazar showed evidence of flaring activity in Fermi data, in spacetime coincidence with a high-energy track detected by IceCube. An a posteriori significance of 2.6σ for the combination of ANTARES and IceCube data is reported.

Keywords: Catalogs, Neutrino astronomy, Astronomy data analysis, Particle astrophysics
Fermi-LAT Detection of GeV γ-Ray Emission from the Highly Asymmetric Shell Supernova Remnant SNR G317.3-0.A. In this paper, we report the first extended GeV γ-ray emission, at a significant level of ∼8.13σ, from the region of the supernova remnant SNR G317.3-0.2 by analyzing ∼12.2 yr of Fermi Large Area Telescope Pass 8 data in the work. The best-fit position of the new γ-ray source matches that of the 843 MHz radio energy band of SNR G317.3-0.2, and there is no significant variability of the photon flux of the corresponding light curve in the data for the 12.2 yr period. Therefore, by excluding other known γ-ray sources or candidates within a 2σ error radius from the best-fit position of SNR G317.3-0.2, we suggest that the γ-ray source is likely to be a GeV counterpart of SNR G317.3-0.2.

Keywords: Supernova remnants, Gamma-ray astronomy, Extended radiation sources, Non-thermal radiation sources
Magnetorotational Instability in Quantum Dusty Plasma. Magnetorotational instability (MRI) in complex quantum plasma, which comprises electron, ion, and dust grains, is investigated. Electrons are considered to be degenerate while ions and dust grains are taken as nondegenerate. The general dispersion relation for MRI with the effect of spin magnetization is derived using local approximations. The instability criteria for spin quantum plasma are derived using low-frequency approximations. Due to the complex nature of the dispersion relation, MHD assumptions are used to define the instability criteria. The dust mass plays a significant role in both the dispersion and growth rate of the magnetorotational mode. The complex mass of dust modifies the instability criteria. Spin magnetization force arises due to electron Pauli spin matrices and has an important role in low-temperature and highly dense plasmas that are found mainly in white dwarfs, neutron stars, and in core-collapse supernovae. It is found that spin magnetization influences the criteria for instability and hence the properties of MHD waves in the degenerate plasma.

Keywords: Astrophysical fluid dynamics, Magnetohydrodynamics, Plasma astrophysics, Plasma physics
HO Puppis: Not a Be Star, but a Newly Confirmed IW And-type Star. HO Puppis (HO Pup) was considered as a Be-star candidate based on its γ Cassiopeiae-type light curve, but lacked spectroscopic confirmation. Using distance measured from Gaia Data Release 2 and the spectral-energy-distribution fit on broadband photometry, the Be-star nature of HO Pup is ruled out. Furthermore, based on the 28,700 photometric data points collected from various time-domain surveys and dedicated intensive-monitoring observations, the light curves of HO Pup closely resemble those of IW And-type stars (as pointed out by Kimura et al.), exhibiting characteristics such as a quasi-standstill phase, brightening, and dips. The light curve of HO Pup displays various variability timescales, including brightening cycles ranging from 23 to 61 days, variations with periods between 3.9 days and 50 minutes during the quasi-standstill phase, and a semiregular ∼14 day period for the dip events. We have also collected time-series spectra (with various spectral resolutions), in which Balmer emission lines and other spectral lines expected for an IW And-type star were detected (even though some of these lines were also expected to be present for Be stars). We detect Bowen fluorescence near the brightening phase, and that can be used to discriminate between IW And-type stars and Be stars. Finally, despite only observing for four nights, the polarization variation was detected, indicating that HO Pup has significant intrinsic polarization.

Keywords: Time series analysis, Be stars, Sky surveys, Dwarf novae
Growth of Massive Disks and Early Disk Fragmentation in Primordial Star Formation. Recent high-resolution simulations demonstrate that disks around primordial protostars easily fragment in the accretion phase before protostars accrete less than a solar mass. To understand why gravitational instability generally causes fragmentation so early, we develop a one-dimensional (1D) nonsteady model of the circumstellar disk that takes the mass supply from an accretion envelope into account. We also compare the model results to a three-dimensional (3D) numerical simulation performed with a code employing adaptive mesh refinement. Our model shows that the self-gravitating disk, through which the Toomre Q parameter is nearly constant at Q ∼ 1, gradually spreads as the disk is fed by the gas infalling from the envelope. We further find that the accretion rate onto the star is an order of magnitude smaller than the mass supply rate onto the disk. This discrepancy makes the disk more massive than the protostar in an early evolutionary stage. Most of the infalling gas is used to extend the outer part of the self-gravitating disk rather than transferred inward toward the star through the disk. We find that similar evolution also occurs in 3D simulations, where the disk becomes three times more massive than the star before the first fragmentation occurs. Our 1D disk model well explains the evolution of the disk-to-star mass ratio observed in the simulation. We argue that the formation of such a massive disk leads to early disk fragmentation.

Keywords: Population III stars, Circumstellar disks
Intermittency of Fast MHD Modes and Regions of Anomalous Gradient Orientation in Low-β Plasmas. The strong alignment of small-scale turbulent Alfvénic motions with the direction of magnetic field that percolates the small-scale eddies and imprints the direction of the magnetic field is a property that follows from the MHD theory and the theory of turbulent reconnection. The Alfvénic eddies mix magnetic fields perpendicular to the direction of the local magnetic field, and this type of motion is used to trace magnetic fields with the velocity gradient technique (VGT). The other type of turbulent motion, fast modes, induces anisotropies orthogonal to Alfvénic eddies and interferes with the tracing of the magnetic field with the VGT. We report a new effect, i.e., in a magnetically dominated low-β subsonic medium, fast modes are very intermittent, and in a volume with a small filling factor the fast modes dominate other turbulent motions. We identify these localized regions as the cause of the occasional change of direction of gradients in our synthetic observations. We show that the new technique of measuring the gradients of gradient amplitudes suppresses the contribution from the fast-mode-dominated regions, improving the magnetic field tracing. In addition, we show that the distortion of the gradient measurements by fast modes is also applicable to the synchrotron intensity gradients, but the effect is reduced compared to the VGT.

Keywords: Interstellar magnetic fields, Interstellar dynamics, Interstellar medium
Probing the Solar Meridional Circulation Using Fourier Legendre Decomposition. We apply the helioseismic methodology of Fourier Legendre decomposition to 88 months of Dopplergrams obtained by the Helioseismic and Magnetic Imager (HMI) as the basis of inferring the depth variation of the mean meridional flow, as averaged between 20° and 60° latitude and in time, in both the northern and southern hemispheres. We develop and apply control procedures designed to assess and remove center-to-limb artifacts using measurements obtained by performing the analysis with respect to artificial poles at the east and west limbs. Forward modeling is carried out using sensitivity functions proportional to the mode kinetic energy density to evaluate the consistency of the corrected frequency shifts with models of the depth variation of the meridional circulation in the top half of the convection zone. The results, taken at face value, imply substantial differences between the meridional circulation in the northern and southern hemispheres. The inferred presence of a return (equatorward propagating) flow at a depth of approximately 40 Mm below the photosphere in the northern hemisphere is surprising and appears to be inconsistent with many other helioseismic analyses. This discrepancy may be the result of the inadequacy of our methodology to remove systematic errors in HMI data. Our results appear to be at least qualitatively similar to those by Gizon et al., which point to an anomaly in HMI data that is not present in MDI or GONG data.

Keywords: Helioseismology, Solar interior, Solar meridional circulation
A Far Ultraviolet Spectroscopic Explorer Survey of Interstellar Molecular Hydrogen in the Galactic Disk. We report results from a Far Ultraviolet Spectrographic Explorer (FUSE) survey of interstellar molecular hydrogen (H2) in the Galactic disk toward 139 O-type and early B-type stars at Galactic latitudes ∣b∣ ≤ 10°, with updated photometric and parallax distances. H2 absorption is measured using the far-UV Lyman and Werner bands, including strong R(0), R(1), and P(1) lines from rotational levels J = 0 and J = 1 and excited states up to J = 5 (sometimes J = 6 and 7). For each sight line, we report column densities NH2, NHI, N(J), and NH = NHI + 2NH2 and the molecular fraction fH2 = 2NH2/NH. Our survey extends the 1977 Copernicus H2 survey up to NH ≈ 5 × 1021 cm-2. The lowest rotational states have excitation temperatures and rms dispersions ⟨T01⟩ = 88 ± 20 K and ⟨T02⟩ = 77 ± 18 K, suggesting that J = 0, 1, 2 are coupled to the gas kinetic temperature. Populations of higher-J states exhibit mean excitation temperatures ⟨T24⟩ = 237 ± 91 K and ⟨T35⟩ = 304 ± 108 K, produced primarily by UV radiative pumping. Correlations of fH2 with E(B - V) and NH show a transition to fH2 ≥ 0.1 at NH ≳ 1021 cm-2 and E(B - V) ≳ 0.2, interpreted with an analytic model of H2 formation-dissociation equilibrium and attenuation of the far-UV radiation field by self-shielding and dust opacity. Results of this disk survey are compared to previous FUSE studies of H2 in translucent clouds, at high Galactic latitudes, and in the Magellanic Clouds. Using updated distances to the target stars, we find average sight-line values ⟨fH2⟩ = 0.20 and ⟨NH/E(B - V)⟩ = 6.07 × 1021 cm-2 mag-1.

Keywords: Interstellar molecules, Ultraviolet astronomy, Milky Way disk, Ultraviolet extinction, Diffuse interstellar clouds
VLA Resolves Unexpected Radio Structures in the Perseus Cluster of Galaxies. We present new deep, high-resolution, 1.5 GHz observations of the prototypical nearby Perseus galaxy cluster from the Karl G. Jansky Very Large Array. We isolate for the first time the complete tail of radio emission of the bent-jet radio galaxy NGC 1272, which had been previously mistaken to be part of the radio mini-halo. The possibility that diffuse radio galaxy emission contributes to mini-halo emission may be a general phenomenon in relaxed cool-core clusters, and should be explored. The collimated jets of NGC 1272 initially bend to the west, and then transition eastward into faint, 60 kpc long extensions with eddy-like structures and filaments. We suggest interpretations for these structures that involve bulk motions of intracluster gas, the galaxy's orbit in the cluster including projection effects, and the passage of the galaxy through a sloshing cold front. Instabilities and turbulence created at the surface of this cold front and in the turbulent wake of the infalling host galaxy most likely play a role in the formation of the observed structures. We also discover a series of faint rings, southeast of NGC 1272, which are a type of structure that has never been seen before in galaxy clusters.

Keywords: Radio galaxies, Tailed radio galaxies, Radio continuum emission, Intracluster medium, Perseus Cluster
Mass and Environment as Drivers of Galaxy Evolution. IV. On the Quenching of Massive Central Disk Galaxies in the Local Universe. The phenomenological study of evolving galaxy populations in Peng et al. has shown that star forming galaxies can be quenched by two distinct processes: mass quenching and environment quenching. To explore the mass quenching process in local galaxies, we study the massive central disk galaxies with stellar mass above the Schechter characteristic mass. In Zhang et al., we showed that during the quenching of the massive central disk galaxies as their star formation rate decreases, their molecular gas mass and star formation efficiency drop rapidly but their H I gas mass remains surprisingly constant. To identify the underlying physical mechanisms, in this work we analyze the change during quenching of various structure parameters, bar frequency, and active galactic nucleus (AGN) activity. We find three closely related facts. On average, as star formation rate decreases in these galaxies: (1) they become progressively more compact, indicated by their significantly increasing concentration index, bulge-to-total mass ratio, and central velocity dispersion, which are mainly driven by the growth and compaction of their bulge component; (2) the frequency of barred galaxies increases dramatically, and at a given concentration index the barred galaxies have a significantly higher quiescent fraction than unbarred galaxies, implying that the galactic bar may play an important role in mass quenching; and (3) the "AGN" frequency increases dramatically from 10% on the main sequence to almost 100% for the most quiescent galaxies, which is mainly driven by the sharp increase of LINERs. These observational results lead to a self-consistent picture of how mass quenching operates.

Keywords: Galaxy structure, Galaxy bulges, Low-luminosity active galactic nuclei, Star formation, Galaxy evolution, Galaxy quenching, Barred spiral galaxies