Sazuna/UAT_keywords huggingface dataset:
The Type Ibn Supernova 2019kbj: Indications for Diversity in Type Ibn Supernova Progenitors. Type Ibn supernovae (SNe) are a rare class of stellar explosions whose progenitor systems are not yet well determined. We present and analyze observations of the Type Ibn SN 2019kbj, and model its light curve in order to constrain its progenitor and explosion parameters. SN 2019kbj shows roughly constant temperature during the first month after peak, indicating a power source (likely circumstellar material interaction) that keeps the continuum emission hot at ~15,000 K. Indeed, we find that the radioactive decay of 56Ni is disfavored as the sole power source of the bolometric light curve. A radioactive decay + circumstellar material (CSM) interaction model, on the other hand, does reproduce the bolometric emission well. The fits prefer a uniform-density CSM shell rather than CSM due to a steady mass-loss wind, similar to what is seen in other Type Ibn SNe. The uniform-density CSM shell model requires ~0.1 M ⊙ of 56Ni and ~1 M ⊙ total ejecta mass to reproduce the light curve. SN 2019kbj differs in this manner from another Type Ibn SN with derived physical parameters, SN 2019uo, for which an order of magnitude lower 56Ni mass and larger ejecta mass were derived. This points toward a possible diversity in SN Ibn progenitor systems and explosions.

Keywords: Massive stars, Supernovae, Core-collapse supernovae
Searching for Supernovae in HETDEX Data Release 3. We have extracted 636 spectra taken at the positions of 583 transient sources from the third data release of the Hobby-Eberly Telescope Dark Energy eXperiment (HETDEX). The transients were discovered by the Zwicky Transient Facility (ZTF) during 2018-2022. The HETDEX spectra provide a potential means to obtain classifications for a large number of objects found by photometric surveys for free. We attempt to explore and classify the spectra by utilizing several template-matching techniques. We have identified two transient sources, ZTF20aatpoos = AT 2020fiz and ZTF19abdkelq, as supernova (SN) candidates. We classify AT 2020fiz as a Type IIP SN observed ~10 days after explosion, and we propose ZTF19abdkelq as a likely Type Ia SN caught ~40 days after maximum light. ZTF photometry of these two sources are consistent with their classifications as SNe. Beside these two objects, we have confirmed several ZTF transients as variable active galactic nuclei based on their spectral appearance, and determined the host galaxy types of several other ZTF transients. * Based on observations obtained with the Hobby-Eberly Telescope (HET), which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Ludwig-Maximillians-Universitaet Muenchen, and Georg-August Universitaet Goettingen. The HET is named in honor of its principal benefactors, William P. Hobby and Robert E. Eberly.

Keywords: Active galactic nuclei, Supernovae, Spectroscopy
Future Prospects on Constraining Neutrino Cosmology with the Ali CMB Polarization Telescope. We forecast the constraints on the parameters of neutrino physics with the constructions of Cosmic Microwave Background (CMB) temperature, E-mode polarization, and lensing spectra for the ground-based Ali Cosmic Microwave Background Polarization Telescope (AliCPT). To implement the forecast calculations, we perform numerical simulations which show that AliCPT would yield the result σ(N eff) = 0.56 and M  ν  &lt; 1.10 eV (95% CL.) with TT, TE, EE, and CMB lensing power spectra for the first year of observation. Moreover, we investigate how the instrumental parameters, such as noise level, FWHM, and sky coverage can affect the constraints on these two parameters. Our forecasting results find that a larger aperture telescope with a larger sky survey strategy would significantly improve the current constraints for AliCPT.

Keywords: Cosmic microwave background radiation, Cosmological neutrinos, Telescopes
Solar Radio Spikes and Type IIIb Striae Manifestations of Subsecond Electron Acceleration Triggered by a Coronal Mass Ejection. Understanding electron acceleration associated with magnetic energy release at subsecond scales presents major challenges in solar physics. Solar radio spikes observed as subsecond, narrow-bandwidth bursts with Δf/f ~ 10-3-10-2 are indicative of a subsecond evolution of the electron distribution. We present a statistical analysis of frequency- and time-resolved imaging of individual spikes and Type IIIb striae associated with a coronal mass ejection (CME). LOFAR imaging reveals that the cotemporal (&lt;2 s) spike and striae intensity contours almost completely overlap. On average, both burst types have a similar source size with a fast expansion at millisecond scales. The radio source centroid velocities are often superluminal and independent of frequency over 30-45 MHz. The CME perturbs the field geometry, leading to increased spike emission likely due to frequent magnetic reconnection. As the field restores itself toward the prior configuration, the observed sky-plane emission locations drift to increased heights over tens of minutes. Combined with previous observations above 1 GHz, the average decay time and source size estimates follow a ~1/f dependence over three decades in frequency, similar to radio-wave scattering predictions. Both time and spatial characteristics of the bursts between 30 and 70 MHz are consistent with radio-wave scattering with a strong anisotropy of the density fluctuation spectrum. Consequently, the site of the radio-wave emission does not correspond to the observed burst locations and implies acceleration and emission near the CME flank. The bandwidths suggest intrinsic emission source sizes &lt;1″ at 30 MHz and magnetic field strengths a factor of two larger than average in events that produce decameter spikes.

Keywords: Solar radio emission, Solar corona
A High-precision Survey of the D/H Ratio in the Nearby Interstellar Medium. We present high signal-to-noise ratio measurements of the H I Lyα absorption line toward 16 Galactic targets that are at distances between approximately 190 and 2200 pc, all beyond the wall of the Local Bubble. We describe the models used to remove stellar emission and absorption features and the methods used to account for all known sources of error in order to compute high-precision values of the H I column density with robust determinations of the uncertainties. When combined with H2 column densities from other sources, we find total H column densities ranging from 1020.01 to 1021.25 cm-2. Using deuterium column densities from Far Ultraviolet Spectroscopic Explorer observations we determine the D/H ratio along the sight lines. We confirm and strengthen the conclusion that D/H is spatially variable over these H I column density and target distance regimes, which predominantly probe the interstellar medium outside the Local Bubble. We discuss how these results affect models of Galactic chemical evolution. We also present an analysis of metal lines along the five sight lines for which we have high-resolution spectra and, along with results reported in the literature, discuss the corresponding column densities in the context of a generalized depletion analysis. We find that D/H is only weakly correlated with metal depletion and conclude that the spatial D/H variability is not solely due to dust depletion. A bifurcation of D/Htot as a function of depletion at high depletion levels provides modest support that deuterium-rich gas is infalling onto the Galactic plane.

Keywords: Galaxy chemical evolution, Interstellar medium
A Population Study of the Radio Emission of Fast Blue Optical Transients. Despite the fact that the progenitor of fast blue optical transients (FBOTs) is still a subject of debate, FBOTs are sometimes suggested to originate from the core collapse of ultra-stripped stars and be powered by a spinning-down neutron star. Following this consideration, it is expected that the late-time evolution of the progenitor stars can leave important imprints in the circumstellar material (CSM) of FBOTs, due to the strong mass loss of the stars. The interaction of the FBOT ejecta with the CSM can drive a long-lasting shock to generate radio emission, which thus enables us to probe the CSM properties through radio observation although such observations are still rare. Within the framework of the magnetar-powered model, Liu et al. fitted the multi-band optical light curves of 40 FBOTs, and hence, the statistical distributions of the FBOT magnetar and ejecta parameters were obtained. Based on these FBOT population results, we investigate the dependence of the radio emission on the mass-loss rate of the progenitors and evaluate the detectability of radio emission from FBOTs with current and future telescopes. It is found that the distribution of the peak time and peak luminosity of the emission at 8.4 GHz are primarily in the regions of t peak,ν  = 102.12±0.63 days and L peak,ν  = 1028.73±0.83 erg s-1 Hz-1, respectively. A joint detection of the Zwicky Transient Facility and Very Large Array could achieve success in about 8.7% FBOTs of z ≤ 1. Furthermore, if considering a joint detection of the Chinese Space Station Telescope and the Square Kilometer Array, this rate of success could be increased to about 23.9%.

Keywords: Transient sources, Supernovae, Radio transient sources
High-frequency Decayless Waves with Significant Energy in Solar Orbiter/EUI Observations. High-frequency wave phenomena present a great deal of interest as one of the possible candidates to contribute to the energy input required to heat the corona as a part of the alternating current heating theory. However, the resolution of imaging instruments up until the Solar Orbiter has made it impossible to resolve the necessary time and spatial scales. The present paper reports on high-frequency transverse motions in a small loop located in a quiet-Sun region of the corona. The oscillations were observed with the High Resolution Imager in the Extreme Ultraviolet telescope (17.4 nm) of the Extreme Ultraviolet Imager instrument on board the Solar Orbiter. We detect two transverse oscillations in short loops with lengths of 4.5 and 11 Mm. The shorter loop displays an oscillation with a 14 s period and the longer a 30 s period. Despite the high resolution, no definitive identification as propagating or standing waves is possible. The velocity amplitudes are found to be equal to 72 and 125 km s-1, respectively, for the shorter and longer loops. Based on that, we also estimated the values of the energy flux contained in the loops-the energy flux of the 14 s oscillation is 1.9 kW m-2 and that of the 30 s oscillation is 6.5 kW m-2. While these oscillations have been observed in the quiet Sun, their energy fluxes are of the same order as the energy input required to heat the active solar corona. Numerical simulations were performed in order to reproduce the observed oscillations. The correspondence of the numerical results to the observations provides support to the estimates of energy content for the observations. Such high energy densities have not yet been observed in decayless coronal waves, and this is promising for coronal heating models based on wave damping.

Keywords: Active solar corona, The Sun, Solar coronal waves
Protracted Timescales for Nebular Processing of First-formed Solids in the Solar System. The calcium-aluminum-rich inclusions (CAIs) from chondritic meteorites are the first solids formed in the solar system. Rim formation around CAIs marks a time period in early solar system history when CAIs existed as free-floating objects and had not yet been incorporated into their chondritic parent bodies. The chronological data on these rims are limited. As seen in the limited number of analyzed inclusions, the rims formed nearly contemporaneously (i.e., &lt;300,000 yr after CAI formation) with the host CAIs. Here we present the relative ages of rims around two type B CAIs from NWA 8323 CV3 (oxidized) carbonaceous chondrite using the 26Al-26Mg chronometer. Our data indicate that these rims formed ~2-3 Ma after their host CAIs, most likely as a result of thermal processing in the solar nebula at that time. Our results imply that these CAIs remained as free-floating objects in the solar nebula for this duration. The formation of these rims coincides with the time interval during which the majority of chondrules formed, suggesting that some rims may have formed in transient heating events similar to those that produced most chondrules in the solar nebula. The results reported here additionally bolster recent evidence suggesting that chondritic materials accreted to form chondrite parent bodies later than the early-formed planetary embryos, and after the primary heat source, most likely 26Al, had mostly decayed away.

Keywords: Carbonaceous chondrites, Cosmochemistry, Protoplanetary disks, Planet formation
Do Hα Stokes V Profiles Probe the Chromospheric Magnetic Field? An Observational Perspective. We investigated the diagnostic potential of the Stokes V profile of the Hα line to probe the chromospheric line-of-sight (LOS) magnetic field (B LOS) by comparing the B LOS inferred from the weak field approximation (WFA) with that inferred from the multiline inversions of the CaII 8542 Å, Si I 8536 Å, and Fe I 8538 Å lines using the STiC inversion code. Simultaneous spectropolarimetric observations of a pore in the Ca II 8542 Å and Hα spectral lines obtained from the SPINOR at the Dunn Solar Telescope on 2008 December 4 are used in this study. The WFA was applied on the Stokes I and V profiles of Hα line over three wavelength ranges, viz., around line core (Δλ = ±0.35 Å), line wings (Δλ = [-1.5, -0.6], and [+0.6, +1.5] Å), and full spectral range of the line (Δλ = ± 1.5 Å) to derive the B LOS. We found the maximum B LOS strengths of ~+800 and ~+600 G at $\mathrm{log}{\tau }_{500}$ = -1 and -4.5, respectively, in the pore. The morphological map of the B LOS inferred from the Hα line core is similar to the B LOS map at $\mathrm{log}{\tau }_{500}$ = -4.5 inferred from multiline inversions. The B LOS map inferred from the Hα line wings and full spectral range have a similar morphological structure to the B LOS map inferred at $\mathrm{log}{\tau }_{500}$ = -1. The B LOS estimated from Hα using WFA is weaker by a factor of ≈0.53 than that of inferred from the multiline inversions. * Not yet released.

Keywords: Solar magnetic fields, Solar chromosphere, Spectropolarimetry, Radiative transfer
Efficient Electron Acceleration Driven by Flux Rope Evolution during Turbulent Reconnection. Magnetic flux ropes or magnetic islands are important structures responsible for electron acceleration and energy conversion during turbulent reconnection. However, the evolution of flux ropes and the corresponding electron acceleration process still remain open questions. In this paper, we present a comparative study of flux ropes observed by the Magnetospheric Multiscale mission in the outflow region during an example of turbulent reconnection in Earth's magnetotail. Interestingly, we find the farther the flux rope is away from the X-line, the bigger the size of the flux rope and the slower it moves. We estimate the power density converted at the observed flux ropes via the three fundamental electron acceleration mechanisms: Fermi, betatron, and parallel electric field. The dominant acceleration mechanism at all three flux ropes is the betatron mechanism. The flux rope that is closest to the X-line, having the smallest size and the fastest moving velocity, is the most efficient in accelerating electrons. Significant energy also returns from particles to fields around the flux ropes, which may facilitate the turbulence in the reconnection outflow region.

Keywords: Space plasmas, Solar magnetic reconnection, Plasma physics, Interplanetary turbulence, Interplanetary particle acceleration
Broadband X-Ray Spectroscopy of the Pulsar Wind Nebula in HESS J1640-465. We present updated measurements of the X-ray properties of the pulsar wind nebula associated with the TeV γ-ray source HESS J1640-465 derived from Chandra and Nuclear Spectroscopic Telescope Array data. We report a high N  H  value along the line of sight, consistent with previous work, which led us to incorporate the effects of dust scattering in our spectral analysis. Due to uncertainties in the dust scattering, we report a range of values for the PWN properties (photon index and unabsorbed flux). In addition, we fit the broadband spectrum of this source and found evidence for spectral softening and decreasing unasborbed flux as we go to higher photon energies. We then used a one-zone time-dependent evolutionary model to reproduce the dynamical and multiwavelength spectral properties of our source. Our model suggests a short spin-down timescale, a relatively higher than average magnetized pulsar wind, a strong pulsar wind nebula magnetic field and maximum electron energy up to PeV, suggesting HESS J1640-465 could be a PeVatron candidate.

Keywords: Neutron stars, X-ray astronomy, Rotation powered pulsars, Millisecond pulsars, Gamma-ray sources, Pulsars, Supernova remnants, Pulsar wind nebulae
Impact of Galaxy Mergers on Stellar Population Profiles of Early-type Galaxies. We study the impact of galaxy mergers on stellar population profiles/gradients of early-type galaxies (ETGs) using ETGs at z &lt; 0.055 in the Stripe 82 region of the Sloan Digital Sky Survey and MaNGA integral field unit spectroscopic data. Tidal features around ETGs, which are detected from deep coadded images, are regarded as direct observational evidence for recent mergers. We find that ETGs with tidal features have less negative metallicity gradients and more positive age gradients than ETGs without tidal features at M star ≳ 1010.6 M ⊙. Moreover, when integrating all the resolved stellar populations, ETGs with tidal features have lower metallicities by ~0.07 dex and younger ages by ~1-2 Gyr than ETGs without tidal features. Analyzing star formation histories, we discover that the mass fraction of young stellar populations with age &lt;5 Gyr is higher in the central regions of ETGs with tidal features than in the same regions of the counterparts without tidal features. Compared to normal ETGs, ETGs with tidal features have a slow metal-enrichment history in the early universe, but they have been accelerating the metal enrichment through recently formed stars over the last few billion years. Many of our results can be explained if the effects of recently occurred mergers are different from those in the early universe, which are more likely to be rich in gas.

Keywords: Galaxy stellar content, Galaxy ages, Tidal tails, Galaxy mergers, Galaxy evolution, Early-type galaxies
The Quest for the Missing Dust. II. Two Orders of Magnitude of Evolution in the Dust-to-gas Ratio Resolved within Local Group Galaxies. We explore evolution in the dust-to-gas ratio with density within four well-resolved Local Group galaxies-the LMC, SMC, M31, and M33. We do this using new Herschel maps, which restore extended emission that was missed by previous Herschel reductions. Combining this sensitivity to diffuse dust emission with excellent physical resolution allows us to probe the dust-to-gas ratio across 2.5 orders of magnitude in interstellar medium (ISM) surface density. We find a significant increase in the dust-to-gas ratio with density, with the dust-to-gas ratio varying within each galaxy by up to a factor 22.4, as density changes. We explore several possible reasons for this, and our favored explanation is that it is being driven by dust grain growth in denser regions of the ISM. We find that the evolution of the dust-to-gas ratio with ISM surface density is very similar between M31 and M33, despite their large differences in mass, metallicity, and star formation rate; conversely, we find M33 and the LMC to have very different dust-to-gas evolution profiles, despite their close similarity in those properties. Our dust-to-gas ratios address previous disagreement between UV- and far-IR-based dust-to-gas estimates for the Magellanic Clouds, removing the disagreement for the LMC, and considerably reducing it for the SMC-with our new dust-to-gas measurements being factors of 2.4 and 2.0 greater than the previous far-IR estimates, respectively. We also observe that the dust-to-gas ratio appears to fall at the highest densities for the LMC, M31, and M33; this is unlikely to be an actual physical phenomenon, and we posit that it may be due to a combined effect of dark gas, and changing dust mass opacity.

Keywords: Local Group, Interstellar dust, Dwarf galaxies, Far infrared astronomy, Submillimeter astronomy
The Optical to Infrared Extinction Law of Magellanic Clouds Based on Red Supergiants and Classical Cepheids. Precise interstellar dust extinction laws are important to infer the intrinsic properties of reddened objects and correctly interpret observations. In this work, we attempt to measure the optical-infrared extinction laws of the Large and Small Magellanic Clouds (LMC and SMC) by using red supergiant (RSG) stars and classical Cepheids as extinction tracers. The spectroscopic RSG samples are constructed based on the APOGEE spectral parameters, Gaia astrometric data, and multiband photometry. We establish the effective temperature-intrinsic color relations for RSG stars and determine the color excess ratio (CER) E(λ - G RP)/E(G BP - G RP) for the LMC and SMC. We use classical Cepheids to derive base relative extinction ${A}_{{G}_{\mathrm{RP}}}/E({G}_{\mathrm{BP}}-{G}_{\mathrm{RP}})$ . The results are 1.589 ± 0.014 and 1.412 ± 0.041 for the LMC and SMC. By combining CERs with ${A}_{{G}_{\mathrm{RP}}}/E({G}_{\mathrm{BP}}-{G}_{\mathrm{RP}})$ , the optical-infrared extinction coefficients ${A}_{\lambda }/{A}_{{G}_{\mathrm{RP}}}$ are determined for 16 bands. We adjust the parameters of R V -dependent extinction laws and obtain average extinction laws for the LMC and SMC of R V = 3.40 ± 0.07 and R V = 2.53 ± 0.10, respectively, which are consistent with Gordon et al. In the optical bands, the adjusted R V extinction curves agree with the observations with deviations less than 3%.

Keywords: Red supergiant stars, Small Magellanic Cloud, Interstellar dust extinction, Reddening law, Large Magellanic Cloud, Interstellar reddening, Interstellar extinction, Magellanic Clouds
Rapid Expansion of the Young Type Ia Supernova Remnant 0519-69.0: More Evidence for a Circumstellar Shell. The nature of Type Ia supernovae remains controversial. The youngest remnants of Ia supernovae hold clues to the explosion and to the immediate surroundings. We present a third epoch of Chandra observations of the ~600 yr old Type Ia remnant 0519-69.0 in the Large Magellanic Cloud, extending the time baseline to 21 yr from the initial 2000 observations. We find rapid expansion of X-ray emitting material, with an average velocity of 4760 km s-1. At the distance of the LMC, this corresponds to an undecelerated age of 750 yr, with the true age somewhat lower. We also find that the bright ring of emission has expanded by 1.3%, corresponding to a velocity of 1900 km s-1 and an undecelerated age of 1600 yr. The high velocity of the peripheral X-rays, contrasted with the modest expansion of the main X-ray shell, provides further evidence for a massive shell of circumstellar material.

Keywords: Supernova remnants, Interstellar medium