adsabs/SciX_UAT_keywords huggingface dataset:
Incremental Fermi Large Area Telescope Fourth Source Catalog

We present an incremental version (4FGL-DR3, for Data Release 3) of the fourth Fermi Large Area Telescope (LAT) catalog of γ-ray sources. Based on the first 12 years of science data in the energy range from 50 MeV to 1 TeV, it contains 6658 sources. The analysis improves on that used for the 4FGL catalog over eight years of data: more sources are fit with curved spectra, we introduce a more robust spectral parameterization for pulsars, and we extend the spectral points to 1 TeV. The spectral parameters, spectral energy distributions, and associations are updated for all sources. Light curves are rebuilt for all sources with 1 yr intervals (not 2 month intervals). Among the 5064 original 4FGL sources, 16 were deleted, 112 are formally below the detection threshold over 12 yr (but are kept in the list), while 74 are newly associated, 10 have an improved association, and seven associations were withdrawn. Pulsars are split explicitly between young and millisecond pulsars. Pulsars and binaries newly detected in LAT sources, as well as more than 100 newly classified blazars, are reported. We add three extended sources and 1607 new point sources, mostly just above the detection threshold, among which eight are considered identified, and 699 have a plausible counterpart at other wavelengths. We discuss the degree-scale residuals to the global sky model and clusters of soft unassociated point sources close to the Galactic plane, which are possibly related to limitations of the interstellar emission model and missing extended sources.

Keywords: gamma-ray sources; gamma-ray astronomy; blazars; pulsars; sky surveys; celestial objects catalogs
Population Properties of Compact Objects from the Second LIGO-Virgo Gravitational-Wave Transient Catalog

We report on the population of 47 compact binary mergers detected with a false-alarm rate of < $1\,{\mathrm{yr}}^{-1}$ in the second LIGO-Virgo Gravitational-Wave Transient Catalog. We observe several characteristics of the merging binary black hole (BBH) population not discernible until now. First, the primary mass spectrum contains structure beyond a power law with a sharp high-mass cutoff; it is more consistent with a broken power law with a break at ${39.7}_{-9.1}^{+20.3}\,\,{M}_{\odot }$ or a power law with a Gaussian feature peaking at ${33.1}_{-5.6}^{+4.0}\,\,{M}_{\odot }$ (90% credible interval). While the primary mass distribution must extend to $\sim 65\,{M}_{\odot }$ or beyond, only ${2.9}_{-1.7}^{+3.5} \% $ of systems have primary masses greater than $45\,{M}_{\odot }$ . Second, we find that a fraction of BBH systems have component spins misaligned with the orbital angular momentum, giving rise to precession of the orbital plane. Moreover, $12$ %- $44$ % of BBH systems have spins tilted by more than 90°, giving rise to a negative effective inspiral spin parameter, ${\chi }_{\mathrm{eff}}$ . Under the assumption that such systems can only be formed by dynamical interactions, we infer that between 25% and 93% of BBHs with nonvanishing $| {\chi }_{\mathrm{eff}}| \gt 0.01$ are dynamically assembled. Third, we estimate merger rates, finding ${{ \mathcal R }}_{\mathrm{BBH}}={23.9}_{-8.6}^{+14.3}\,\,{\mathrm{Gpc}}^{-3}\,{\mathrm{yr}}^{-1}$ for BBHs and ${{ \mathcal R }}_{\mathrm{BNS}}={320}_{-240}^{+490}\,\,{\mathrm{Gpc}}^{-3}\,{\mathrm{yr}}^{-1}$ for binary neutron stars. We find that the BBH rate likely increases with redshift ( $85 \% $ credibility) but not faster than the star formation rate ( $86 \% $ credibility). Additionally, we examine recent exceptional events in the context of our population models, finding that the asymmetric masses of GW190412 and the high component masses of GW190521 are consistent with our models, but the low secondary mass of GW190814 makes it an outlier.

Keywords: gravitational waves; astrophysical black holes; stellar mass black holes; massive stars; compact objects; bayesian statistics
NICER-NuSTAR Observations of the Neutron Star Low-mass X-Ray Binary 4U 1735-44

We report on the first simultaneous Neutron Star Interior Composition Explore (NICER) and Nuclear Spectroscopic Telescope Array (NuSTAR) observations of the neutron star (NS) low-mass X-ray binary 4U 1735-44, obtained in 2018 August. The source was at a luminosity of ∼1.8 (D/5.6 kpc)2 × 1037 erg s-1 in the 0.4-30 keV band. We account for the continuum emission with two different continuum descriptions that have been used to model the source previously. Despite the choice in continuum model, the combined passband reveals a broad Fe K line indicative of reflection in the spectrum. In order to account for the reflection spectrum we utilize a modified version of the reflection model RELXILL that is tailored for thermal emission from accreting NSs. Alternatively, we also use the reflection convolution model of RFXCONV to model the reflected emission that would arise from a Comptonized thermal component for comparison. We determine that the innermost region of the accretion disk extends close to the innermost stable circular orbit (RISCO) at the 90% confidence level regardless of reflection model. Moreover, the current flux calibration of NICER is within 5% of the NuSTAR/FPMA(B).

Keywords: accretion; neutron stars; low-mass x-ray binary stars
The Dwarf Galaxy Population at z 0.7: A Catalog of Emission Lines and Redshifts from Deep Keck Observations

We present a catalog of spectroscopically measured redshifts over 0 < z < 2 and emission-line fluxes for 1440 galaxies. The majority (~65%) of the galaxies come from the HALO7D survey, with the remainder from the DEEPwinds program. This catalog includes redshifts for 646 dwarf galaxies with $\mathrm{log}({M}_{\star }/{M}_{\odot })\lt 9.5$ . Eight-hundred and ten catalog galaxies did not have previously published spectroscopic redshifts, including 454 dwarf galaxies. HALO7D used the DEIMOS spectrograph on the Keck II telescope to take very deep (up to 32 hr exposure, with a median of ~7 hr) optical spectroscopy in the COSMOS, EGS, GOODS-North, and GOODS-South CANDELS fields, and in some areas outside CANDELS. We compare our redshift results to existing spectroscopic and photometric redshifts in these fields, finding only a 1% rate of discrepancy with other spectroscopic redshifts. We measure a small increase in median photometric redshift error (from 1.0% to 1.3%) and catastrophic outlier rate (from 3.5% to 8%) with decreasing stellar mass. We obtained successful redshift fits for 75% of massive galaxies, and demonstrate a similar 70%-75% successful redshift measurement rate in $8.5\lt \mathrm{log}({M}_{\star }/{M}_{\odot })\lt 9.5$ galaxies, suggesting similar survey sensitivity in this low-mass range. We describe the redshift, mass, and color-magnitude distributions of the catalog galaxies, finding HALO7D galaxies representative of CANDELS galaxies up to i-band magnitudes of 25. The catalogs presented will enable studies of star formation, the mass-metallicity relation, star formation-morphology relations, and other properties of the z ~ 0.7 dwarf galaxy population.

Keywords: dwarf galaxies; emission line galaxies; galaxy spectroscopy; catalogs; redshift surveys; star formation
Velocity-space Signatures of Resonant Energy Transfer between Whistler Waves and Electrons in the Earth's Magnetosheath

Wave-particle interactions play a crucial role in transferring energy between electromagnetic fields and charged particles in space and astrophysical plasmas. Despite the prevalence of different electromagnetic waves in space, there is still a lack of understanding of fundamental aspects of wave-particle interactions, particularly in terms of energy flow and velocity-space characteristics. In this study, we combine a novel quasilinear model with observations from the Magnetospheric Multiscale mission to reveal the signatures of resonant interactions between electrons and whistler waves in magnetic holes, which are coherent structures often found in the Earth's magnetosheath. We investigate the energy transfer rates and velocity-space characteristics associated with Landau and cyclotron resonances between electrons and slightly oblique propagating whistler waves. In the case of our observed magnetic hole, the loss of electron kinetic energy primarily contributes to the growth of whistler waves through the n = -1 cyclotron resonance, where n is the order of the resonance expansion in linear Vlasov-Maxwell theory. The excitation of whistler waves leads to a reduction of the temperature anisotropy and parallel heating of the electrons. Our study offers a new and self-consistent understanding of resonant energy transfer in turbulent plasmas.

Keywords: solar wind; interplanetary turbulence; space plasmas
Disentangling the Black Hole Mass Spectrum with Photometric Microlensing Surveys

From the formation mechanisms of stars and compact objects to nuclear physics, modern astronomy frequently leverages surveys to understand populations of objects to answer fundamental questions. The population of dark and isolated compact objects in the Galaxy contains critical information related to many of these topics, but is only practically accessible via gravitational microlensing. However, photometric microlensing observables are degenerate for different types of lenses, and one can seldom classify an event as involving either a compact object or stellar lens on its own. To address this difficulty, we apply a Bayesian framework that treats lens type probabilistically and jointly with a lens population model. This method allows lens population characteristics to be inferred despite intrinsic uncertainty in the lens class of any single event. We investigate this method's effectiveness on a simulated ground-based photometric survey in the context of characterizing a hypothetical population of primordial black holes (PBHs) with an average mass of 30M ⊙. On simulated data, our method outperforms current black hole (BH) lens identification pipelines and characterizes different subpopulations of lenses while jointly constraining the PBH contribution to dark matter to ≈25%. Key to robust inference, our method can marginalize over population model uncertainty. We find the lower mass cutoff for stellar origin BHs, a key observable in understanding the BH mass gap, particularly difficult to infer in our simulations. This work lays the foundation for cutting-edge PBH abundance constraints to be extracted from current photometric microlensing surveys.

Keywords: gravitational microlensing; microlensing parallax; dark matter; primordial black holes; black holes; astrophysical black holes; bayesian statistics; astrostatistics techniques; astrostatistics tools
Cataclysmic Variables in the First Year of the Zwicky Transient Facility

Using selection criteria based on amplitude, time, and color, we have identified 329 objects as known or candidate cataclysmic variables (CVs) during the first year of testing and operation of the Zwicky Transient Facility. Of these, 90 are previously confirmed CVs, 218 are strong candidates based on the shape and color of their light curves obtained during 3-562 days of observation, and the remaining 21 are possible CVs but with too few data points to be listed as good candidates. Almost half of the strong candidates are within 10 deg of the galactic plane, in contrast to most other large surveys that have avoided crowded fields. The available Gaia parallaxes are consistent with sampling the low mass transfer CVs, as predicted by population models. Our follow-up spectra have confirmed Balmer/helium emission lines in 27 objects, with four showing high-excitation He II emission, including candidates for an AM CVn, a polar, and an intermediate polar. Our results demonstrate that a complete survey of the Galactic plane is needed to accomplish an accurate determination of the number of CVs existing in the Milky Way.

Keywords: astronomical object identification; compact binary stars; spectroscopy; dwarf novae
High-resolution Spectroscopic Monitoring Observations of FU Orionis-type Object, V960 Mon

We present the results of high-resolution (R ≥ 30,000) optical and near-infrared (NIR) spectroscopic monitoring observations of an FU Orionis-type object (FUor), V960 Mon, which underwent an outburst in 2014 November. We have monitored this object with the Bohyunsan Optical Echelle Spectrograph and the Immersion GRating INfrared Spectrograph since 2014 December. Various features produced by a wind, disk, and outflow/jet were detected. The wind features varied over time and continually weakened after the outburst. We detected double-peaked line profiles in the optical and NIR, and the line widths tend to decrease with increasing wavelength, indicative of Keplerian disk rotation. The disk features in the optical and NIR spectra fit well with G-type and K-type stellar spectra convolved with a kernel to account for the maximum projected disk rotation velocities of about 40.3 ± 3.8 km s-1 and 36.3 ± 3.9 km s-1, respectively. We also report the detection of [S II] and H2 emission lines, which are jet/outflow tracers and rarely found in FUors.

Keywords: fu orionis stars; high resolution spectroscopy
ALMA Lensing Cluster Survey: ALMA-Herschel Joint Study of Lensed Dusty Star-forming Galaxies across z ≃ 0.5 - 6

We present an ALMA-Herschel joint analysis of sources detected by the ALMA Lensing Cluster Survey (ALCS) at 1.15 mm. Herschel/PACS and SPIRE data at 100-500 μm are deblended for 180 ALMA sources in 33 lensing cluster fields that are detected either securely (141 sources; in our main sample) or tentatively at S/N ≥ 4 with cross-matched HST/Spitzer counterparts, down to a delensed 1.15 mm flux density of ~0.02 mJy. We performed far-infrared spectral energy distribution modeling and derived the physical properties of dusty star formation for 125 sources (109 independently) that are detected at >2σ in at least one Herschel band. A total of 27 secure ALCS sources are not detected in any Herschel bands, including 17 optical/near-IR-dark sources that likely reside at z = 4.2 ± 1.2. The 16th, 50th, and 84th percentiles of the redshift distribution are 1.15, 2.08, and 3.59, respectively, for ALCS sources in the main sample, suggesting an increasing fraction of z ≃ 1 - 2 galaxies among fainter millimeter sources (f 1150 ~ 0.1 mJy). With a median lensing magnification factor of $\mu ={2.6}_{-0.8}^{+2.6}$ , ALCS sources in the main sample exhibit a median intrinsic star formation rate of ${94}_{-54}^{+84}$ M ⊙ yr-1, lower than that of conventional submillimeter galaxies at similar redshifts by a factor of ~3. Our study suggests weak or no redshift evolution of dust temperature with L IR < 1012 L ⊙ galaxies within our sample at z ≃ 0 - 2. At L IR > 1012 L ⊙, the dust temperatures show no evolution across z ≃ 1-4 while being lower than those in the local universe. For the highest-redshift source in our sample (z = 6.07), we can rule out an extreme dust temperature (>80 K) that was reported for MACS0416 Y1 at z = 8.31.

Keywords: high-redshift galaxies; luminous infrared galaxies; gravitational lensing; ultraluminous infrared galaxies; galaxy evolution
The Discovery and Evolution of a Possible New Epoch of Cometary Activity by the Centaur (2060) Chiron

Centaurs are small solar system objects on chaotic orbits in the giant planet region, forming an evolutionary continuum with the Kuiper Belt objects and Jupiter-family comets. Some Centaurs are known to exhibit cometary activity, though unlike comets, this activity tends not to correlate with heliocentric distance, and the mechanism behind it is currently poorly understood. We utilize serendipitous observations from the Asteroid Terrestrial-impact Last Alert System, Zwicky Transient Facility, Panoramic Survey Telescope and Rapid Response System, Dark Energy Survey, and Gaia in addition to targeted follow-up observations from the Las Cumbres Observatory, TRAnsiting Planets and PlanetesImals Small Telescope South (TRAPPIST-South), and Gemini North telescope to analyze an unexpected brightening exhibited by the known active Centaur (2060) Chiron in 2021. This is highly indicative of a cometary outburst. As of 2023 February, Chiron had still not returned to its prebrightening magnitude. We find Chiron's rotational lightcurve, phase curve effects, and possible high-albedo surface features to be unlikely causes of this observed brightening. We consider the most likely cause to be an epoch of either new or increased cometary activity, though we cannot rule out a possible contribution from Chiron's reported ring system, such as a collision of as-yet-unseen satellites shepherding the rings. We find no evidence for a coma in our Gemini or TRAPPIST-South observations, though this does not preclude the possibility that Chiron is exhibiting a coma that is too faint for observation or constrained to the immediate vicinity of the nucleus.

Keywords: centaur group; comae; solar system astronomy; phase angle; broad band photometry; wide-field telescopes; small solar system bodies
Recurrent Narrow Quasiperiodic Fast-propagating Wave Trains Excited by the Intermittent Energy Release in the Accompanying Solar Flare

About the driven mechanisms of the quasiperiodic fast-propagating (QFP) wave trains, there exist two dominant competing physical explanations: they are associated with the flaring energy release or attributed to the waveguide dispersion. Employing Solar Dynamics Observatory/Atmospheric Imaging Assembly 171 Å images, we investigated a series of QFP wave trains composed of multiple wave fronts propagating along a loop system during the accompanying flare on 2011 November 11. The wave trains showed a high correlation in start times with the energy release of the accompanying flare. Measurements show that the wave trains' phase speed is almost consistent with its group speed with a value of about 1000 km s-1, indicating that the wave trains should not be considered dispersed waves. The period of the wave trains was the same as that of the oscillatory signal in X-ray emissions released by the flare. Thus we propose that the QFP wave trains were most likely triggered by the flare rather than by dispersion. We investigated the seismological application with the QFP waves and then obtained that the magnetic field strength of the waveguide was about 10 G. Meanwhile, we also estimated that the energy flux of the wave trains was about 1.2 × 105 erg cm-2 s-1.

Keywords: solar coronal waves; solar corona; alfven waves
Estimating Dust Attenuation From Galactic Spectra. II. Stellar and Gas Attenuation in Star-forming and Diffuse Ionized Gas Regions in MaNGA

We investigate the dust attenuation in both stellar populations and ionized gas in kiloparsec-scale regions in nearby galaxies using integral field spectroscopy data from MaNGA MPL-9. We identify star-forming (H II) and diffuse ionized gas (DIG) regions from MaNGA data cubes. From the stacked spectrum of each region, we measure the stellar attenuation, $E{\left(B-V\right)}_{\mathrm{star}}$ , using the technique developed by Li et al., as well as the gas attenuation, $E{\left(B-V\right)}_{\mathrm{gas}}$ , from the Balmer decrement. We then examine the correlation of $E{\left(B-V\right)}_{\mathrm{star}}$ , $E{\left(B-V\right)}_{\mathrm{gas}}$ , $E{\left(B-V\right)}_{\mathrm{gas}}-E{\left(B-V\right)}_{\mathrm{star}}$ , and $E{\left(B-V\right)}_{\mathrm{star}}/E{\left(B-V\right)}_{\mathrm{gas}}$ with 16 regional/global properties, and for regions with different Hα surface brightnesses (ΣHα). We find a stronger correlation between $E{\left(B-V\right)}_{\mathrm{star}}$ and $E{\left(B-V\right)}_{\mathrm{gas}}$ in regions of higher ΣHα. The luminosity-weighted age (tL) is found to be the property that is the most strongly correlated with $E{\left(B-V\right)}_{\mathrm{star}}$ , and consequently, with $E{\left(B-V\right)}_{\mathrm{gas}}-E{\left(B-V\right)}_{\mathrm{star}}$ and $E{\left(B-V\right)}_{\mathrm{star}}/E{\left(B-V\right)}_{\mathrm{gas}}$ . At fixed ΣHα, ${\mathrm{log}}_{10}$ tL is linearly and negatively correlated with $E{\left(B-V\right)}_{\mathrm{star}}/E{\left(B-V\right)}_{\mathrm{gas}}$ at all ages. Gas-phase metallicity and ionization level are important for the attenuation in the gas. Our results indicate that the ionizing source for DIG regions is likely distributed in the outskirts of galaxies, while for H II regions, our results can be well explained by the two-component dust model of Charlot & Fall.

Keywords: interstellar dust; interstellar dust extinction; stellar populations; hot ionized medium; warm ionized medium; galaxy spectroscopy; emission nebulae; interstellar extinction; star formation
Search for PeV Gamma-Ray Emission from the Southern Hemisphere with 5 Yr of Data from the IceCube Observatory

The measurement of diffuse PeV gamma-ray emission from the Galactic plane would provide information about the energy spectrum and propagation of Galactic cosmic rays, and the detection of a pointlike source of PeV gamma-rays would be strong evidence for a Galactic source capable of accelerating cosmic rays up to at least a few PeV. This paper presents several unbinned maximum-likelihood searches for PeV gamma-rays in the Southern Hemisphere using 5 yr of data from the IceTop air shower surface detector and the in-ice array of the IceCube Observatory. The combination of both detectors takes advantage of the low muon content and deep shower maximum of gamma-ray air showers and provides excellent sensitivity to gamma-rays between ∼0.6 and 100 PeV. Our measurements of pointlike and diffuse Galactic emission of PeV gamma-rays are consistent with the background, so we constrain the angle-integrated diffuse gamma-ray flux from the Galactic plane at 2 PeV to 2.61 × 10-19 cm-2 s-1 TeV-1 at 90% confidence, assuming an E-3 spectrum, and we estimate 90% upper limits on pointlike emission at 2 PeV between 10-21 and 10-20 cm-2 s-1 TeV-1 for an E-2 spectrum, depending on decl. Furthermore, we exclude unbroken power-law emission up to 2 PeV for several TeV gamma-ray sources observed by the High Energy Spectroscopic System and calculate upper limits on the energy cutoffs of these sources at 90% confidence. We also find no PeV gamma-rays correlated with neutrinos from IceCube's high-energy starting event sample. These are currently the strongest constraints on PeV gamma-ray emission.

Keywords: particle astrophysics; galactic cosmic rays; gamma-rays; cosmic rays