Sazuna/UAT_keywords huggingface dataset:
A New Tool for Understanding the Solar Wind-Venus Interaction: Three-dimensional Multifluid MHD Model. In this paper, we present a new tool to investigate the interaction of the solar wind with Venus with the approach of a global multifluid magnetohydrodynamics (MHD) model. The continuity, momentum, and energy equations for H+, O+, ${{\rm{O}}}_{2}^{+}$ , and ${\mathrm{CO}}_{2}^{+}$ are solved self-consistently together with Faraday's law. The photochemistry of ionospheric ions are considered as the source term in the density, momentum, and energy equations for each ion. We found that the simulated ionospheric density, temperature, and the bow shock location are consistent with previous observations and simulations for both the solar maximum and minimum. The simulated magnetic fields also agree well with the Venus Express observations. Meanwhile, the high-resolving power and low numerical diffusion makes the model capable of capturing the fine structures of the Venusian-induced magnetosphere, such as the Kelvin-Helmholtz instability and the nightside wake. The escape rates have also been estimated and the results are similar to previous estimations. The high-resolution model could be an efficient tool for the exploration of the fine structures of the Venusian space environment system, and also for the application to other unmagnetized planets.

Keywords: Planetary magnetospheres, Planetary ionospheres, Magnetohydrodynamical simulations
X-ray Time Lag Evaluation of MAXI J1820+070 with a Differential Cross-correlation Analysis. MAXI J1820+070 is a transient black hole binary discovered on 2018 March 11. The unprecedented rich statistics brought by the NICER X-ray telescope allow detailed timing analyses up to ~1 kHz uncompromised by photon shot noise. To estimate the time lags, a Fourier analysis was applied, which led to two different conclusions for the system configuration: one supporting a lamp-post configuration with a stable accretion disk extending close to the innermost stable circular orbit and the other supporting a truncated accretion disk contracting with time. Using the same data set, we present the results based on the cross-correlation function (CCF). The CCF is calculated between two different X-ray bands where one side is subtracted from the other side, which we call the differential CCF (dCCF). Soft and hard lags of ~0.03 and 3 s, respectively, are clearly identified without being diluted by the spectral mixture, demonstrating the effectiveness of the dCCF analysis. The evolution of these lags is tracked, along with spectral changes for the first 120 days since discovery. Both the dCCF and spectral fitting results are interpreted as the soft lag being a reverberation lag between the Comptonized emission and the soft excess emission, and that the hard lag is between the disk blackbody emission and the Comptonized emission. The evolutions of these lags are in line with the picture of a truncated disk contracting with time.

Keywords: X-ray astronomy, Astrostatistics tools, Stellar accretion disks, Black holes, Astrostatistics, Low-mass x-ray binary stars
Constraints on Fluctuating Star Formation Rates for Intermediate-mass Galaxies with Hα and UV Luminosities. We study the recent star formation histories (SFHs) of 575 intermediate-mass galaxies (IMGs, 109 ≤ M/M ⊙ ≤ 1010) in COSMOS at 0.3 &lt; z &lt; 0.4 by comparing their Hα and UV luminosities. These two measurements trace star formation rates (SFRs) on different timescales and together reveal fluctuations in recent activity. We compute L Hα  from Magellan IMACS spectroscopy, while L UV is derived from rest-frame 2800 Å photometry. Dust corrections are applied to each band independently. We compare the deviation of L Hα  and L UV from their respective star-forming sequences (i.e., ${\rm{\Delta }}\mathrm{log}{L}_{{\rm{H}}\alpha }$ and ${\rm{\Delta }}\mathrm{log}{L}_{\mathrm{UV}}$ ), and after accounting for observational uncertainties we find a small intrinsic scatter between the two quantities (σ  δ  ≲ 0.03 dex). This crucial observational constraint precludes strong fluctuations in the recent SFHs of IMGs: simple linear SFH models indicate that a population of IMGs would be limited to only factors of ≲2 change in SFR over 200 Myr and ≲30% on shorter timescales of 20 Myr. No single characteristic SFH for IMGs, such as an exponentially rising/falling burst, can reproduce the individual and joint distribution of ${\rm{\Delta }}\mathrm{log}{L}_{{\rm{H}}\alpha }$ and ${\rm{\Delta }}\mathrm{log}{L}_{\mathrm{UV}}$ . Instead, an ensemble of SFHs is preferred. Finally, we find that IMG SFHs predicted by recent hydrodynamic simulations, in which feedback drives rapid and strong SFR fluctuations, are inconsistent with our observations.

Keywords: Galaxy formation, Star formation, Galaxy evolution, Galaxy spectroscopy, Galaxies
HectoMAP: The Complete Redshift Survey (Data Release 2). HectoMAP is a dense redshift survey of 95,403 galaxies based primarily on MMT spectroscopy with a median redshift z = 0.345. The survey covers 54.64 deg2 in a 1.°5 wide strip across the northern sky centered at a decl. of 43.°25. We report the redshift, the spectral indicator D  n 4000, and the stellar mass. The red-selected survey is 81% complete for 55,962 galaxies with (g - r) &gt; 1 and r &lt; 20.5; it is 72% complete for 32,908 galaxies with (g - r) &gt; 1, (r - i) &gt; 0.5 and 20.5 &lt; r &lt; 21.3. Comparison of the survey basis SDSS photometry with the HSC-SSP photometry demonstrates that HectoMAP provides complete magnitude-limited surveys based on either photometric system. We update the comparison between the HSC-SSP photometric redshifts with HectoMAP spectroscopic redshifts; the comparison demonstrates that the HSC-SSP photometric redshifts have improved between the second and third data releases. HectoMAP is a foundation for examining the quiescent galaxy population (63% of the survey), clusters of galaxies, and the cosmic web. HectoMAP is completely covered by the HSC-SSP survey, thus enabling a variety of strong- and weak-lensing investigations.

Keywords: Galaxy clusters, Redshift surveys, Large-scale structure of the universe
GRB 171205A: Hypernova and Newborn Neutron Star. GRB 171205A is a low-luminosity, long-duration gamma-ray burst (GRB) associated with SN 2017iuk, a broad-line type Ic supernova (SN). It is consistent with having been formed in the core collapse of a widely separated binary, which we have called the binary-driven hypernova of type III. The core collapse of the CO star forms a newborn NS (νNS) and the SN explosion. Fallback accretion transfers mass and angular momentum to the νNS, here assumed to be born non-rotating. The accretion energy injected into the expanding stellar layers powers the prompt emission. The multiwavelength power-law afterglow is explained by the synchrotron radiation of electrons in the SN ejecta, powered by energy injected by the spinning νNS. We calculate the amount of mass and angular momentum gained by the νNS, as well as the νNS rotational evolution. The νNS spins up to a period of 47 ms, then releases its rotational energy powering the synchrotron emission of the afterglow. The paucity of the νNS spin explains the low-luminosity characteristic and that the optical emission of the SN from the nickel radioactive decay outshines the optical emission from the synchrotron radiation. From the νNS evolution, we infer that the SN explosion had to occur at most 7.36 h before the GRB trigger. Therefore, for the first time, the analysis of the GRB data leads to the time of occurrence of the CO core collapse leading to the SN explosion and the electromagnetic emission of the GRB event.

Keywords: Neutron stars, Gamma-ray bursts, Pulsars
Observational Study of Recurrent Jets Confined by Active Region Loops. With high spatial and temporal resolution data from the Solar Dynamics Observatory and the New Vacuum Solar Telescope (NVST), we present observations of recurrent jets confined by coronal loops that occurred in the active region NOAA 11726 from 02:00 to 12:00 UT on 2013 April 21. Three jets are clearly observed by the NVST in Hα line. These recurrent jets originate from the emerging bipolar magnetic region at the north of the active region. Half of them are related to the magnetic flux emergence, and the others are associated with the magnetic flux cancellation. Their velocities range from 80.6 ± 1.3 km s-1 to 433.6 ± 20.1 km s-1. Though they eject from the same source region, their shapes, sizes, and eruptive trajectories are not exactly the same. Most of them consist of cool (dark) and hot (bright) components. The differential emission measure distributions of the recurrent jets suggest that they are multithermal structures. The rotation directions of the recurrent jets are not consistent. Eight of them have a counterclockwise rotation, and the others have a clockwise rotation. The 12 recurrent jets are classified as blowout (accounting for 33%) and standard (accounting for 67%) jets. The velocity and density range of the blowout jets are slightly wider than those of the standard jets. The blowout jets have lower temperatures than the standard jets. These observational results suggest that the recurrent jets are probably triggered by recurrent magnetic reconnection between the emerging bipolar magnetic region and its overlying large-scale active region loops.

Keywords: Solar magnetic fields, Solar coronal transients, Solar magnetic reconnection
The Differential Assembly History of the Centers and Outskirts of Main-sequence Galaxies at z   2.3. We present a study of spatially resolved star formation histories (SFHs) for 60 z ~ 2.3 main-sequence, star-forming galaxies selected from the MOSDEF spectroscopic survey in the GOODS-N field, with median stellar mass $\mathrm{log}({M}_{\star }/{M}_{\odot })$ = 9.75 and spanning the range $8.6\lt \mathrm{log}({M}_{\star }/{M}_{\odot })\lt 11.5$ . Photometry is decomposed into a central and an outer spatial component using observed z F850LP - H F160W colors. The PROSPECTOR code is used to model spectral energy distributions for the center, outskirt, and integrated galaxy using Hubble Space Telescope/ACS and WFC3, Spitzer/IRAC, and ground-based photometry, with additional constraints on gas-phase metallicity and spectroscopic redshift from MOSDEF spectroscopy. For the low-resolution bands, spatially resolved photometry is determined with an iterative approach. The reconstructed SFHs indicate that the majority of galaxies with $\mathrm{log}({M}_{\star }/{M}_{\odot })\lt 10.5$ are observed while their central regions undergo relatively recent (&lt;100 Myr) bursts of star formation, whereas the outskirts have a smooth, quasi-steady SFH that gently increases toward the redshift of observation. The enhanced star formation activity of the central parts is broadly consistent with the idea that it is produced by highly dissipative gas compaction and accretion. The wide range of central densities and sizes observed in the sample suggests that, for the selected galaxies, such a process has started but is still far from being completed. The implication would be that selecting star-forming galaxies at cosmic noon frequently includes systems in an "evolved" evolutionary phase where the centers have recently started a burst of star formation activity that will likely initiate inside-out quenching in the next several hundred million years.

Keywords: Galaxy formation, Spectral energy distribution, Galaxy evolution
Prospects for Extending the Core-collapse Supernova Detection Horizon Using High-energy Neutrinos. Large neutrino detectors like IceCube monitor for core-collapse supernovae using low-energy (MeV) neutrinos with a detection reach from a supernova neutrino burst to the Magellanic Cloud. However, some models predict the emission of high-energy neutrinos of GeV-TeV from core-collapse supernovae through the interaction of ejecta with circumstellar material with energies of TeV-PeV produced through choked jets. In this paper, we explore the detection horizon of IceCube for core-collapse supernovae using high-energy neutrinos from these models. We examine the potential of two high-energy neutrino data samples from IceCube, one that performs best in the northern sky and one that has better sensitivity in the southern sky. We demonstrate that, by using high-energy neutrinos from core-collapse supernovae, the detection reach can be extended to the megaparsec range, far beyond what is accessible through low-energy neutrinos. Looking ahead to IceCube-Gen2, this reach will be extended considerably.

Keywords: Neutrino telescopes, Supernova neutrinos, High energy astrophysics, Core-collapse supernovae, Cosmological neutrinos, Particle astrophysics
GASP. XLV. Stellar Bars in Jellyfish Galaxies: Analysis of Ionized Gas and Stellar Populations. Stellar bars have been found to substantially influence the properties of stellar populations in galaxies, affecting their ability to form stars. While this can be easily seen when studying galaxies in relatively isolated environments, such type of analysis requires a higher degree of complexity when cluster galaxies are considered, due to the variety of interactions that can potentially occur in these denser environments. We use IFU MUSE data from the GASP survey to study the combined effect of the presence of a stellar bar and ram pressure, on spatially resolved properties of stellar populations. We have analyzed spatially resolved indicators of both recent star formation rates (SFRs) and average stellar population ages to check for signatures of anomalous central star formation activity, also taking into account the possible presence of nuclear activity. We found an increase in central SFR in ram-pressure-affected galaxies when compared with unperturbed ones. The most extreme cases of increased SFR and central rejuvenation occur in barred galaxies that are at advanced stages of ram pressure stripping. For low-mass barred galaxies affected by ram pressure, the combined effect is the systematic enhancement of the star formation activity as opposed to the case of high-mass galaxies, which present both enhancement and suppression. Barred galaxies that present suppression of their star formation activity also present signatures of nuclear activity. Our results indicate that the combined effect of the presence of a bar and strong perturbation by ram pressure is able to trigger the central star formation activity and probably ignite nuclear activity.

Keywords: Galaxy clusters, Spiral galaxies, Ram pressure stripped tails, Star formation, Galaxy evolution, Barred spiral galaxies
Radiative Transfer in Lyα Nebulae. I. Modeling a Continuous or Clumpy Spherical Halo with a Central Source. To understand the mechanism behind high-z Lyα nebulae, we simulate the scattering of Lyα in a H I halo about a central Lyα source. For the first time, we consider both smooth and clumpy distributions of halo gas, as well as a range of outflow speeds, total H I column densities, H I spatial concentrations, and central source galaxies (e.g., with Lyα line widths corresponding to those typical of active galactic nucleus or star-forming galaxies). We compute the spatial-frequency diffusion and the polarization of the Lyα photons scattered by atomic hydrogen. Our scattering-only model reproduces the typical size of Lyα nebulae (~100 kpc) at total column densities N H I ≥ 1020 cm-2 and predicts a range of positive, flat, and negative polarization radial gradients. We also find two general classes of Lyα nebula morphologies: with and without bright cores. Cores are seen when N H I is low, i.e., when the central source is directly visible, and are associated with a polarization jump, a steep increase in the polarization radial profile just outside the halo center. Of all the parameters tested in our smooth or clumpy medium model, N H I dominates the trends. The radial behaviors of the Lyα surface brightness, spectral line shape, and polarization in the clumpy model with covering factor f  c  ≳ 5 approach those of the smooth model at the same N H I. A clumpy medium with high N H I and low f  c  ≲ 2 generates Lyα features via scattering that the smooth model cannot: a bright core, symmetric line profile, and polarization jump.

Keywords: Lyman-alpha galaxies, Radiative transfer simulations, Emission nebulae, Radiative transfer
Search for Ultraheavy Dark Matter from Observations of Dwarf Spheroidal Galaxies with VERITAS. Dark matter is a key piece of the current cosmological scenario, with weakly interacting massive particles (WIMPs) a leading dark matter candidate. WIMPs have not been detected in their conventional parameter space (100 GeV ≲M  χ  ≲ 100 TeV), a mass range accessible with current Imaging Atmospheric Cherenkov Telescopes. As ultraheavy dark matter (UHDM; M  χ  ≳ 100 TeV) has been suggested as an underexplored alternative to the WIMP paradigm, we search for an indirect dark matter annihilation signal in a higher mass range (up to 30 PeV) with the VERITAS γ-ray observatory. With 216 hr of observations of four dwarf spheroidal galaxies, we perform an unbinned likelihood analysis. We find no evidence of a γ-ray signal from UHDM annihilation above the background fluctuation for any individual dwarf galaxy nor for a joint-fit analysis, and consequently constrain the velocity-weighted annihilation cross section of UHDM for dark matter particle masses between 1 TeV and 30 PeV. We additionally set constraints on the allowed radius of a composite UHDM particle.

Keywords: Gamma-ray astronomy, Dwarf spheroidal galaxies, Dark matter, High energy astrophysics
A Study of Preflare Solar Coronal Magnetic Fields: Magnetic Energy and Helicity. Solar flares fall into two types, with eruptive ones associated with coronal mass ejection (CME) and confined ones without CME. To explore whether there are preflare conditions in terms of magnetic energy and helicity that can effectively determine the types of flares, here we analyzed a suite of related parameters of the reconstructed preflare coronal magnetic field of major solar flares, either eruptive or confined, from 2011 to 2017 near the solar disk center. The investigated parameters include extensive-type quantities such as the total magnetic energy E  T , the potential energy E  P , the free energy E  F , the relative helicity H  R , and the nonpotential helicity H  J , as well as the intensive-type indices E  F /E  P , ∣H  J /H  R ∣, $| {H}_{R}/{\phi }^{{\prime} 2}| $ , and $| {H}_{J}/{\phi }^{{\prime} 2}| $ , where ${\phi }^{{\prime} }$ is half of the total unsigned magnetic flux. We have the following key findings: (1) None of the extensive parameters can effectively distinguish the eruptive and confined potential of the preflare coronal fields, though the confined events have averagely larger values. (2) All the intensive parameters have significantly larger average and median values for eruptive flares than the confined events, which indicates that the field for eruptive flares has overall higher degree of nonpotentiality and complexity than that of the confined flares. (3) The energy ratio E  F /E  P  and the normalized nonpotential helicity $| {H}_{J}/{\phi }^{{\prime} 2}| $ , which are strongly correlated with each other, have among the highest capability of distinguishing the fields that possibly produce a major eruptive or confined flare, as over 75% of all the events are successfully discriminated between eruptive and confined flares by using critical values of E  F /E  P  ≥ 0.27 and $| {H}_{J}/{\phi }^{{\prime} 2}| \geqslant 0.009$ .

Keywords: Solar corona, Solar flares, Solar coronal mass ejections, Magnetic fields
Accumulating Errors in Tests of General Relativity with Gravitational Waves: Overlapping Signals and Inaccurate Waveforms. Observations of gravitational waves (GWs) from compact binary coalescences provide powerful tests of general relativity (GR), but systematic errors in data analysis could lead to incorrect scientific conclusions. This issue is especially serious in the third-generation GW detectors in which the signal-to-noise ratio (S/N) is high and the number of detections is large. In this work, we investigate the impacts of overlapping signals and inaccurate waveform models on tests of GR. We simulate mock catalogs for Einstein Telescope and Cosmic Explorer and perform parametric tests of GR using waveform models with different levels of inaccuracy. We find that the systematic error in non-GR parameter estimates could accumulate toward a false deviation from GR when combining results from multiple events, although a Bayesian model selection analysis may not favor a deviation. Waveform inaccuracies contribute most to the systematic errors, but multiple overlapping signals could magnify the effects of systematics owing to the incorrect removal of signals. We also point out that testing GR using selected "golden binaries" with high S/N is even more vulnerable to false deviations from GR. The problem of error accumulation is universal; we emphasize that it must be addressed to fully exploit the data from third-generation GW detectors and that further investigations, particularly in waveform accuracy, will be essential.

Keywords: General relativity, Gravitational waves
Precursors of Supernovae from Mass Eruption: Prospects for Early Warning of Nearby Core-collapse Supernovae. Recent observations of a large fraction of Type II supernovae (SNe) show traces of dense circumstellar medium (CSM) very close to the progenitor star. If this CSM is created by eruptive mass loss several months before core collapse, the eruption itself may be visible as a precursor, helpful as an early warning of a near-future SN. Using radiation hydrodynamical simulations based on the open-source code CHIPS, we theoretically model the emission from the mass eruption of a red supergiant star. We find that for a modest mass eruption the luminosity is typically on the order of 1039 erg s-1, can last as long as hundreds of days until the star explodes, and is mainly bright in the infrared (from -9 to -11 mag around peak). We discuss observational strategies to find these signatures from Galactic and local Type II SNe.

Keywords: Type II supernovae, Circumstellar matter, Transient sources, Core-collapse supernovae
The First Flight of the Marshall Grazing Incidence X-Ray Spectrometer (MaGIXS). The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) sounding rocket experiment launched on 2021 July 30 from the White Sands Missile Range in New Mexico. MaGIXS is a unique solar observing telescope developed to capture X-ray spectral images of coronal active regions in the 6-24 Å wavelength range. Its novel design takes advantage of recent technological advances related to fabricating and optimizing X-ray optical systems, as well as breakthroughs in inversion methodologies necessary to create spectrally pure maps from overlapping spectral images. MaGIXS is the first instrument of its kind to provide spatially resolved soft X-ray spectra across a wide field of view. The plasma diagnostics available in this spectral regime make this instrument a powerful tool for probing solar coronal heating. This paper presents details from the first MaGIXS flight, the captured observations, the data processing and inversion techniques, and the first science results.

Keywords: Solar atmosphere, Solar coronal heating, Solar x-ray emission, Solar active regions, Solar corona, Spectroscopy, Active solar corona