Sazuna/UAT_keywords huggingface dataset:
Gravitational-wave Constraints on the Cosmic Opacity at z ∼ 5: Forecast from Space Gravitational-wave Antenna DECIGO. Since gravitational waves (GWs) propagate freely through a perfect fluid, coalescing compact binary systems as standard sirens allow us to measure the luminosity distance directly and provide distance measurements unaffected by the cosmic opacity. DECi-hertz Interferometer Gravitational-wave Observatory (DECIGO) is a future Japanese space gravitational-wave antenna sensitive to frequency range between target frequencies of the Laser Interferometric Space Antenna and ground-based detectors. Combining the predicted future GW observations from DECIGO and three current popular astrophysical probes (H II regions, SNe Ia Pantheon sample, quasar sample) in electromagnetic domains, one would be able to probe the opacity of the universe at different redshifts. In this paper, we show that the cosmic-opacity parameter can be constrained to a high precision (Δɛ ∼ 10-2) out to high redshifts (z ∼ 5). In order to reconstruct the evolution of cosmic opacity without assuming any particular functional form of it, the cosmic-opacity tests should be applied to individual redshift bins independently. Therefore, we also calculate the optical depth at individual redshifts and averaged τ(z) within redshift bins. Our findings indicate that, compared with the results obtained from the H II galaxies and Pantheon SNe Ia, there is an improvement in precision when the quasar sample is considered. While nonzero optical depth is statistically significant only for redshift ranges 0 &lt; z &lt; 0.5, 1 &lt; z &lt; 2, and 2.5 &lt; z &lt; 3.5, such a tendency is different from that obtained in the framework of its parameterized form. Therefore, the importance of a cosmic-opacity test without a prescribed phenomenological function should be emphasized.

Keywords: Gravitational wave detectors, Gravitational waves, Cosmological parameters
All the PAHs: An AKARI-Spitzer Cross-archival Spectroscopic Survey of Aromatic Emission in Galaxies. We present a large sample of 2.5-38 μm galaxy spectra drawn from a cross-archival comparison in the AKARI-Spitzer Extragalactic Spectral Survey, and investigate a subset of 113 star-forming galaxies with prominent polycyclic aromatic hydrocarbon (PAH) emission spanning a wide range of star formation properties. With AKARI's extended 2.5-5 μm wavelength coverage, we self-consistently model for the first time all PAH emission bands using a modified version of PAHFIT. We find LPAH 3.3/LIR ∼ 0.1%, and the 3.3 μm PAH feature contributes ∼1.5%-3% to the total PAH power—somewhat less than earlier dust models have assumed. We establish a calibration between 3.3 μm PAH emission and star formation rate, but also find regimes where it loses reliability, including at high luminosity and low metallicity. The 3.4 μm aliphatic emission and a broad plateau feature centered at 3.47 μm are also modeled. As the PAH feature with the shortest wavelength, the one at 3.3 μm is susceptible to attenuation, leading to differences of a factor of ∼3 in the inferred star formation rate at high obscuration with different assumed attenuation geometries. Surprisingly, LPAH 3.3/LΣ PAH shows no sign of decline at high luminosities, and the low-metallicity dwarf galaxy II Zw 40 exhibits an unusually strong 3.3 μm band; both results suggest either that the smallest PAHs are better able to survive under intense radiation fields than presumed, or that PAH emission is shifted to shorter wavelengths in intense and high-energy radiation environments. A photometric surrogate for 3.3 μm PAH luminosity using JWST/NIRCam is provided and found to be highly reliable at low redshift.

Keywords: Starburst galaxies, Polycyclic aromatic hydrocarbons, Interstellar dust extinction, Ultraluminous infrared galaxies, Luminous infrared galaxies
Serendipitous Discovery of Nine White Dwarfs with Gaseous Debris Disks. Optical spectroscopic observations of white dwarf stars selected from catalogs based on the Gaia DR2 database reveal nine new gaseous debris disks that orbit single white dwarf stars, about a factor of 2 increase over the previously known sample. For each source we present gas emission lines identified and basic stellar parameters, including abundances for lines seen with low-resolution spectroscopy. Principle discoveries include (1) the coolest white dwarf (Teff ≍ 12,720 K) with a gas disk; this star, WD0145+234, has been reported to have undergone a recent infrared outburst; (2) co-location in velocity space of gaseous emission from multiple elements, suggesting that different elements are well mixed; (3) highly asymmetric emission structures toward SDSS J0006+2858, and possibly asymmetric structures for two other systems; (4) an overall sample composed of approximately 25% DB and 75% DA white dwarfs, consistent with the overall distribution of primary atmospheric types found in the field population; and (5) never-before-seen emission lines from Na in the spectra of Gaia J0611-6931, semi-forbidden Mg, Ca, and Fe lines toward WD 0842+572, and Si in both stars. The currently known sample of gaseous debris disk systems is significantly skewed toward northern hemisphere stars, suggesting a dozen or so emission line stars are waiting to be found in the southern hemisphere.

Keywords: Circumstellar matter, White dwarf stars, Stellar abundances, Exoplanet systems
Herschel/PACS OH Spectroscopy of Seyfert, LINER, and Starburst Galaxies. We investigated the 65, 71, 79, 84, 119, and 163 μm OH doublets of 178 local (0 &lt; z &lt; 0.35) galaxies. They were observed using the Herschel/Photoconductor Array Camera and Spectrometer, including Seyfert galaxies, low-ionization nuclear emission-line regions, and star-forming galaxies. We observe these doublets exclusively in absorption (OH71), primarily in absorption (OH65, OH84), mostly in emission (OH79), only in emission (OH163), and an approximately even mix of the both (OH119). In 19 galaxies we find P Cygni or reverse P Cygni line profiles in the OH doublets. We use several galaxy observables to probe spectral classification, brightness of a central active galactic nucleus (AGN)/starburst component, and radiation field strength. We find that OH79, OH119, and OH163 are more likely to display strong emission for bright, unobscured AGNs. For less luminous, obscured AGNs and nonactive galaxies, we find populations of strong absorption (OH119), weaker emission (OH163), and a mix of weak emission and weak absorption (OH79). For OH65, OH71, and OH84, we do not find significant correlations with the observables listed above. For OH79 and OH119, we find relationships with both the 9.7 μm silicate feature and Balmer decrement dust extinction tracers in which more dust leads to weaker emission/stronger absorption. The origin of emission for the observed OH doublets, whether from collisional excitation or from radiative pumping by infrared photons, is discussed. * Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Keywords: Seyfert galaxies, Active galaxies, Infrared galaxies, Galaxy counts
The Zwicky Transient Facility Census of the Local Universe. I. Systematic Search for Calcium-rich Gap Transients Reveals Three Related Spectroscopic Subclasses. Using the Zwicky Transient Facility alert stream, we are conducting a large spectroscopic campaign to construct a complete, volume-limited sample of transients brighter than 20 mag, and coincident within 100″ of galaxies in the Census of the Local Universe catalog. We describe the experiment design and spectroscopic completeness from the first 16 months of operations, which have classified 754 supernovae. We present results from a systematic search for calcium-rich gap transients in the sample of 22 low-luminosity (peak absolute magnitude M &gt; -17), hydrogen-poor events found in the experiment. We report the detection of eight new events, and constrain their volumetric rate to ≳15% ± 5% of the SN Ia rate. Combining this sample with 10 previously known events, we find a likely continuum of spectroscopic properties ranging from events with SN Ia-like features (Ca-Ia objects) to those with SN Ib/c-like features (Ca-Ib/c objects) at peak light. Within the Ca-Ib/c events, we find two populations distinguished by their red (g - r ≈ 1.5 mag) or green ( $g-r\approx 0.5$ mag) colors at the r-band peak, wherein redder events show strong line blanketing features and slower light curves (similar to Ca-Ia objects), weaker He lines, and lower [Ca II]/[O I] in the nebular phase. We find that all together the spectroscopic continuum, volumetric rates, and striking old environments are consistent with the explosive burning of He shells on low-mass white dwarfs. We suggest that Ca-Ia and red Ca-Ib/c objects arise from the double detonation of He shells, while green Ca-Ib/c objects are consistent with low-efficiency burning scenarios like detonations in low-density shells or deflagrations.

Keywords: White dwarf stars, Supernovae, Compact objects
Helioseismic Finite-frequency Sensitivity Kernels for Flows in Spherical Geometry including Systematic Effects. Helioseismic inferences of large-scale flows in the solar interior necessitate accounting for the curvature of the Sun, both in interpreting systematic trends introduced in measurements as well as the sensitivity kernel that relates photospheric measurements to subsurface flow velocities. Additionally, the inverse problem that relates measurements to model parameters needs to be well posed to obtain accurate inferences, which necessitates a sparse set of parameters. Further, the sensitivity functions need to be computationally easy to evaluate. In this work, we address these issues by demonstrating that the sensitivity kernels for flow velocities may be computed efficiently on the basis of vector spherical harmonics. We are also able to account for line-of-sight projections in Doppler measurements, as well as center-to-limb differences in line-formation heights. We show that given the assumed spherical symmetry of the background model, it is often cheap to simultaneously compute the kernels for pairs of observation points that are related by a rotation. Such an approach is therefore particularly well suited to inverse problems for large-scale flows in the Sun, such as meridional circulation.

Keywords: Helioseismology, The Sun, Solar interior, Solar meridional circulation
The Saga of M81: Global View of a Massive Stellar Halo in Formation. Recent work has shown that Milky Way-mass galaxies display an incredible range of stellar halo properties, yet the origin of this diversity is unclear. The nearby galaxy M81—currently interacting with M82 and NGC 3077—sheds unique light on this problem. We present a Subaru Hyper Suprime-Cam survey of the resolved stellar populations around M81, revealing M81's stellar halo in never-before-seen detail. We resolve the halo to unprecedented V-band equivalent surface brightnesses of 33 mag arcsec -2 and produce the first-ever global stellar mass density map for a Milky Way-mass stellar halo outside of the Local Group. Using the minor axis, we confirm M81's halo as one of the lowest mass and metal poorest known (M⋆ ≃ 1.16 × 109M⊙, [Fe/H] ≃ -1.2)—indicating a relatively quiet prior accretion history. Yet, our global halo census finds that tidally unbound material from M82 and NGC 3077 provides a substantial infusion of metal-rich material (M⋆ ≃ 5.4 × 108 M⊙, [Fe/H] ≃-0.9). We further show that, following the accretion of its massive satellite M82 (and the LMC-like NGC 3077), M81 will host one of the most massive and metal-rich stellar halos in the nearby universe. Thus, the saga of M81: following a passive history, M81's merger with M82 will completely transform its halo from a low-mass, anemic halo rivaling the Milky Way, to a metal-rich behemoth rivaled only by systems such as M31. This dramatic transformation indicates that the observed diversity in stellar halo properties is primarily driven by diversity in the largest mergers these galaxies have experienced.

Keywords: Galaxy stellar halos, Galaxy formation, Galaxy evolution, Galaxy mergers
Star Formation and Evolution of Blister-type H II Region Sh2-112. We report the observational findings of the Sh2-112 H II region by using the multiwavelength data analysis ranging from optical to radio wavelengths. This region is powered by the massive O8V-type star BD +45 3216. The surface density distribution and minimum spanning tree analyses of the young stellar object (YSO) candidates in the region reveal their groupings toward the western periphery of the H II region. A GMRT radio continuum emission peak is found toward the northwest boundary of the H II region and is investigated as a compact/ultracompact H II region candidate powered by a B0-B0.5-type star. Toward the southwest direction, a prominent curved rim-like structure is found in the Hα image and GMRT radio continuum maps, where the H2 and 13CO emission is also observed. These results suggest the existence of the ionized boundary layer (IBL) on the surface of the molecular cloud. This IBL is found to be overpressured with respect to the internal pressure of the surrounding molecular cloud. This implies that the shocks are propagating/propagated into the molecular cloud, and the young stars identified within it are likely triggered due to the massive star. It is also found that this region is ionization-bounded toward the west and density-bounded toward the east. Based on the distribution of the ionized gas, molecular material, and YSO candidates, we propose that the Sh2-112 H II region is a good candidate for the blister-type H II region that has been evolved on the surface of a cylindrical molecular cloud.

Keywords: Young stellar objects, Star formation, H II regions
Early Spectral Evolution of Classical Novae: Consistent Evidence for Multiple Distinct Outflows. The physical mechanism driving mass ejection during a nova eruption is still poorly understood. Possibilities include ejection in a single ballistic event, a common-envelope interaction, a continuous wind, or some combination of these processes. Here, we present a study of 12 Galactic novae, for which we have premaximum high-resolution spectroscopy. All 12 novae show the same spectral evolution. Before optical peak, they show a slow P Cygni component. After peak, a fast component quickly arises, while the slow absorption remains superimposed on top of it, implying the presence of at least two physically distinct flows. For novae with high-cadence monitoring, a third, intermediate-velocity component is also observed. These observations are consistent with a scenario where the slow component is associated with the initial ejection of the accreted material and the fast component with a radiation-driven wind from the white dwarf. When these flows interact, the slow flow is swept up by the fast flow, producing the intermediate component. These colliding flows may produce the γ-ray emission observed in some novae. Our spectra also show that the transient heavy-element absorption lines seen in some novae have the same velocity structure and evolution as the other lines in the spectrum, implying an association with the nova ejecta rather than a preexisting circumbinary reservoir of gas or material ablated from the secondary. While this basic scenario appears to qualitatively reproduce multiwavelength observations of classical novae, substantial theoretical and observational work is still needed to untangle the rich diversity of nova properties.

Keywords: High resolution spectroscopy, White dwarf stars, Novae, Compact objects, Spectroscopy, Cataclysmic variable stars, Classical novae
PSR J1641+3627F: A Low-mass He White Dwarf Orbiting a Possible High-mass Neutron Star in the Globular Cluster M13. We report on the discovery of the companion star to the millisecond pulsar J1631+3627F in the globular cluster M13. By means of a combination of optical and near-UV high-resolution observations obtained with the Hubble Space Telescope, we identified the counterpart at the radio source position. Its location in the color-magnitude diagrams reveals that the companion star is a faint ( $V\approx 24.3$ ) He-core white dwarf. We compared the observed companion magnitudes with those predicted by state-of-the-art binary evolution models and found out that it has a mass of $0.23\pm 0.03\,{M}_{\odot }$ , a radius of ${0.033}_{-0.005}^{+0.004}\,{R}_{\odot }$ , and a surface temperature of $11,{500}_{-1300}^{+1900}$ K. Combining the companion mass with the pulsar mass function is not enough to determine the orbital inclination and the neutron star mass; however, the last two quantities become correlated: we found that either the system is observed at a low-inclination angle, or the neutron star is massive. In fact, assuming that binaries are randomly aligned with respect to the observer line of sight, there is a $\sim 70 \% $ of probability that this system hosts a neutron star more massive than $1.6\,{M}_{\odot }$ . In fact, the maximum and median mass of the neutron star, corresponding to orbital inclination angles of 90° and 60°, are ${M}_{\mathrm{NS},\max }=3.1\pm 0.6\,{M}_{\odot }$ and ${M}_{\mathrm{NS},\mathrm{med}}=2.4\pm 0.5\,{M}_{\odot }$ , respectively. On the other hand, also assuming an empirical neutron star mass probability distribution, we found that this system could host a neutron star with a mass of $1.5\pm 0.1\,{M}_{\odot }$ if orbiting with a low-inclination angle around 40°.

Keywords: Globular star clusters, Neutron stars, Binary stars, Millisecond pulsars, White dwarf stars, Compact binary stars, HST photometry, Pulsars, Binary pulsars, Star clusters
The Importance of Hall Effect in the Self-similar Collapse of a Filamentary Cloud. Thanks to the observational and simulation works, the importance of the nonideal magnetohydrodynamic (MHD) effects, i.e., Hall effect, ohmic resistivity, and ambipolar diffusion, have been well established at various stages of cloud evolution. To get a comparison between the Hall effect with other effects, we aim to model the time evolution of a rotating filamentary molecular cloud during the isothermal/polytropic collapse phase in the presence of the Hall drift. Three components of the velocity vector are investigated when the angular momentum is fully coupled with the magnetic field at large radii of a filament. For this purpose, the nonideal MHD equations in the self-similar formalism are considered at large radii of a molecular cloud where the magnetic field evolution is affected by the Hall drift. Then, the connection between the self-similar approach with the observational data from the filamentary clouds is examined to get a realistic model. Due to the existence of Hall drift, the significant changes on the rotation of the cloud can be seen when the cloud switches from the isothermal collapse phase to the polytropic collapse phase. Also, the results of this model are useful in the study of the multiple star formation process as well as the initial conditions for driving the outflows during the collapse of the filamentary clouds. Finally, we found that there are some conditions for the comparability of the Hall effect with the ambipolar diffusion in the outer regions of the clouds.

Keywords: Star forming regions, Magnetic fields
Nitric Oxide and Other Molecules: Molecular Modeling and Low-frequency Exploration Using the Murchison Widefield Array. We present new molecular modeling for 14NO and 15NO and a deep, blind molecular line survey at low radio frequencies (99-129 MHz). This survey is the third in a series completed with the Murchison Widefield Array (MWA), but in comparison with the previous surveys, uses 4 times more data (17 hr versus 4 hr) and is 3 times better in angular resolution (1' versus 3'). The new molecular modeling for nitric oxide and its main isotopologue has seven transitions within the MWA frequency band (although we also present the higher-frequency transitions). Although we did not detect any new molecular lines at a limit of 0.21 Jy beam-1, this work is an important step in understanding the data processing challenges for the future Square Kilometre Array and places solid limits on what is expected in the future of low-frequency surveys. The modeling can be utilized for future searches of nitric oxide.

Keywords: Interstellar molecules, Surveys, Molecular spectroscopy, Astrochemistry, Interstellar medium, Radio astronomy
Calibration of the MaGIXS Experiment. I. Calibration of the X-Ray Source at the X-Ray and Cryogenic Facility. The Marshall Grazing Incidence Spectrometer (MaGIXS) is a sounding rocket experiment that will observe the soft X-ray spectrum of the Sun from 24 to 6.0 Å (0.5-2.0 keV) and is scheduled for launch in 2021. Component- and instrument-level calibrations for the MaGIXS instrument are carried out using the X-ray and Cryogenic Facility (XRCF) at NASA Marshall Space Flight Center. In this paper, we present the calibration of the incident X-ray flux from the electron impact source with different targets at the XRCF using a CCD camera; the photon flux at the CCD was low enough to enable its use as a "photon counter," i.e., the ability to identify individual photon hits and calculate their energy. The goal of this paper is two-fold: (1) to confirm that the flux measured by the XRCF beam normalization detectors is consistent with the values reported in the literature and therefore reliable for MaGIXS calibration and (2) to develop a method of counting photons in CCD images that best captures their number and energy.

Keywords: X-ray detectors, Solar x-ray emission, X-ray telescopes, Flux calibration, Solar corona
Starspot Modulation Detected in the Detached Eclipsing Binary KIC 8301013. We investigate a short-period (P ≈ 4.4 days) eclipsing binary KIC 8301013 using high-quality Kepler photometry and the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectroscopic data. Through the light-curve and radial-velocity synthesis using the Wilson-Devinney method, it reveals that the binary is an almost circular (e ≈ 0.001), detached system composed of two late F-type main-sequence stars, with masses and radii of ${M}_{1}=1.29\pm 0.02{M}_{\odot }$ , R1 = 1.45 ± 0.01R⊙ and M2 = 1.11 ± 0.05M⊙, R2 = 1.20 ± 0.01R⊙ for the primary and secondary, respectively. Besides the light variations due to the eclipses, the light curve shows quasi-sinusoidal variations that could be ascribed to starspot modulation. After removing the synthetic binary light curve from the detrended Kepler data, we measure the periods of the active region rotation by using the autocorrelation function (ACF) and Lomb-Scargle periodograms, the decay timescale of the active region by fitting the ACF of out-of-eclipse residuals, and the size of the active region represented by the rms scatter of the out-of-eclipse residuals. The activity level on the binary is significantly stronger than the Sun and has a better agreement with individual F-type stars. No periodic changes are detected in the active region evolution. Thus, KIC 8301013 is an interesting sample for the study of starspot modulation.

Keywords: Eclipsing binary stars, Starspots, Stellar rotation