Sazuna/UAT_keywords huggingface dataset:
The Fraction and Kinematics of Broad Absorption Line Quasars across Cosmic Time. Luminous quasars are powerful targets to investigate the role of feedback from supermassive black holes (BHs) in regulating the growth phases of BHs themselves and of their host galaxies, up to the highest redshifts. Here we investigate the cosmic evolution of the occurrence and kinematics of BH-driven outflows, as traced by broad absorption line (BAL) features, due to the C IV ionic transition. We exploit a sample of 1935 quasars at z = 2.1-6.6 with bolometric luminosity log(L bol/erg s-1) ≳ 46.5, drawn from the Sloan Digital Sky Survey and from the X-Shooter legacy survey of Quasars at the Reionization Epoch (XQR-30). We consider rest-frame optical bright quasars to minimize observational biases due to quasar selection criteria. We apply a homogeneous BAL-identification analysis, based on employing composite template spectra to estimate the quasar intrinsic emission. We find a BAL quasar fraction close to 20% at z ~ 2-4, while it increases to almost 50% at z ~ 6. The velocity and width of the BAL features also increase at z ≳ 4.5. We exclude the possibility that the redshift evolution of the BAL properties is due to differences in terms of quasar luminosity and accretion rate. These results suggest significant BH feedback occurring in the 1 Gyr old universe, likely affecting the growth of BHs and, possibly, of their host galaxies, as supported by models of early BH and galaxy evolution.

Keywords: Supermassive black holes, Broad-absorption line quasar, Quasars, Galaxy evolution, Spectroscopy, High-redshift galaxies
3D Spectroscopy with GTC-MEGARA of the Triple AGN Candidate in SDSS J102700.40+174900.8. Triple-active galactic nucleus (AGN) systems are expected to be the result of the hierarchical model of galaxy formation. Since there are very few of them confirmed as such, we present the results of a new study of the triple AGN candidate SDSS J102700.40+174900.8 (center nucleus) through observations with the GTC-MEGARA Integral Field Unit. 1D and 2D analysis of the line ratios of the three nuclei allow us to locate them in the EW(Hα) versus [N II]/Hα diagram. The central nucleus is found to be a retired galaxy (or fake AGN). The neighbors are found to be a strong AGN (southeastern nucleus, J102700.55+174900.2), compatible with a Seyfert 2 (Sy2) galaxy, and a weak AGN (northern nucleus, J102700.38+174902.6), compatible with a LINER2. We find evidence that the neighbors constitute a dual AGN system (Sy2-LINER2) with a projected separation of 3.98 kpc in the optical bands. The Hα velocity map shows that the northern nucleus has an Hα emission with a velocity offset of ~-500 km s-1, whereas the southeastern nucleus has a rotating disk and Hα extended emission at kiloparsec scales. Chandra archival data confirm that the neighbors have X-ray (0.5-2) keV and (2-7) keV emission, whereas the center nucleus shows no X-ray emission. A collisional ring with knots is observed in Hubble Space Telescope images of the southeastern nucleus. These knots coincide with star formation regions that, along with the ring, are predicted in a head-on collision. In this case, the morphology changes are probably due to a minor merger that was produced by the passing of the northern through the southeastern nucleus.

Keywords: Galaxy interactions, Astronomical techniques, Seyfert galaxies, Active galactic nuclei, X-ray active galactic nuclei, Galaxy spectroscopy
On Detecting Interstellar Scintillation in Narrowband Radio SETI. To date, the search for radio technosignatures has focused on sky location as a primary discriminant between technosignature candidates and anthropogenic radio frequency interference (RFI). In this work, we investigate the possibility of searching for technosignatures by identifying the presence and nature of intensity scintillations arising from the turbulent, ionized plasma of the interstellar medium. Past works have detailed how interstellar scattering can both enhance and diminish the detectability of narrowband radio signals. We use the NE2001 Galactic free electron density model to estimate scintillation timescales to which narrowband signal searches would be sensitive, and discuss ways in which we might practically detect strong intensity scintillations in detected signals. We further analyze the RFI environment of the Robert C. Byrd Green Bank Telescope with the proposed methodology and comment on the feasibility of using scintillation as a filter for technosignature candidates.

Keywords: Astronomy data modeling, Technosignatures, Interstellar plasma, Astrobiology, Interstellar scintillation, Search for extraterrestrial intelligence
Probing the Heart of Active Narrow-line Seyfert 1 Galaxies with VERA Wideband Polarimetry. We explored the parsec-scale nuclear regions of a sample of radio-loud narrow-line Seyfert 1 galaxies (NLSy1s) using the VLBI Exploration of Radio Astrometry wideband (at a recording rate of 16 Gbps) polarimetry at 22 and 43 GHz. Our targets include 1H 0323+342, SBS 0846+513, PMN J0948+0022, 1219+044, PKS 1502+036, and TXS 2116-077, which are all known to exhibit γ-ray emission indicative of possessing highly beamed jets similar to blazars. For the first time, we unambiguously detected Faraday rotation toward the parsec-scale radio core of NLSy1s, with a median observed core rotation measure (RM) of 2.7 × 103 rad m-2 (or 6.3 × 103 rad m-2 for redshift-corrected). This level of RM magnitude is significantly larger than those seen in the core of BL Lacertae objects (BLOs; a dominant subclass of blazars), suggesting that the nuclear environment of NLSy1s is more gas-rich than that in BLOs. Interestingly, the observed parsec-scale polarimetric properties of NLSy1s (low core fractional polarization, large core RM and jet-EVPA misalignment) are rather similar to those of flat-spectrum radio quasars (FSRQs). Our results are in accordance with the scenario that NLSy1s are in an early stage of active galactic nucleus evolution with their central black hole masses being smaller than those of more evolved FSRQs.

Keywords: Radio jets, Very long baseline interferometry, Seyfert galaxies, Active galactic nuclei, Polarimetry
Big Three Dragons: Molecular Gas in a Bright Lyman-break Galaxy at z = 7.15. We report Atacama Large Millimeter/submillimeter Array Band 3 observations of CO(6-5), CO(7-6), and [C I](2-1) in B14-65666 ("Big Three Dragons"), one of the brightest Lyman-break galaxies at z &gt; 7 in the rest-frame ultraviolet continuum, far-infrared continuum, and emission lines of [O III] 88 μm and [C II] 158 μm. CO(6-5), CO(7-6), and [C I](2-1), whose 3σ upper limits on the luminosities are approximately 40 times fainter than the [C II] luminosity, are all not detected. The L [C II]/L CO(6-5) and L [C II]/L CO(7-6) ratios are higher than the typical ratios obtained in dusty star-forming galaxies or quasar host galaxies at similar redshifts, and they may suggest a lower gas density in the photodissociated region in B14-65666. By using the (1) [C II] luminosity, (2) dust mass-to-gas mass ratio, and (3) a dynamical mass estimate, we find that the molecular gas mass (M mol) is (0.05-11) × 1010 M ⊙. This value is consistent with the upper limit inferred from the nondetection of mid-J CO and [C I](2-1). Despite the large uncertainty in M mol, we estimate a molecular gas-to-stellar mass ratio (μ gas) of 0.65-140 and a gas depletion time (τ dep) of 2.5-550 Myr; these values are broadly consistent with those of other high-redshift galaxies. B14-65666 could be an ancestor of a passive galaxy at z ≳ 4 if no gas is fueled from outside the galaxy.

Keywords: Interstellar medium, High-redshift galaxies, Galaxies
Pulsation-induced Spectroscopic Variability of IRAS Z02229+6208. Monitoring of high-resolution spectra in the optical and near-infrared wavelength region was carried out for the early post-AGB stage star IRAS Z02229+6208 with the CARMENES instrument to reveal spectroscopic variability over the pulsation cycle of 154 days. Significant changes are seen in both the intensity and position of carbon-bearing molecular lines. Strong and broad CN red system lines, blueshifted up to 9.4 km s−1 relative to the stellar photosphere, are seen near the light minimum. Near the light maxima, the molecular features are weak and most of them are in emission, e.g., broad emissions in the CN red system (0,0) lines are seen. A site of formation of molecular absorptions and emissions appears to be an extended atmosphere of a cool post-AGB star affected by stellar pulsation. In addition, we observed narrow absorption lines of the C2 Phillips (2, 0), (3, 0) system and the CN red system (2,0), most likely related to the circumstellar envelope produced during the evolution on the asymptotic giant branch (AGB). An expansion velocity of the circumstellar shell was found to be V exp = −11.1 km s−1 relative to the stellar mass center, in agreement with that estimated before from CO lines. The observed spectroscopic variability seems to be typical for pulsating early post-AGB stage stars.

Keywords: High resolution spectroscopy, Circumstellar envelopes, Post-asymptotic giant branch stars, Shocks, Spectral line identification, Stellar winds, Circumstellar shells, Stellar oscillations, Stellar atmospheres, Stellar evolution
Comparing Complex Chemistry in Neighboring Hot Cores: NOEMA Studies of W3(H<SUB>2</SUB>O) and W3(OH). Presented here are NOEMA interferometric observations of the neighboring hot cores W3(H2O) and W3(OH). The presence of two star-forming cores at different evolutionary stages within the same parent cloud presents a unique opportunity to study how the physics of the source and its evolutionary stage impact the chemistry. Through spectral analysis and imaging, we identify over 20 molecules in these cores. Most notably, we have detected HDO and CH3CH2CN in W3(OH), which were previously not detected in this core. We have imaged the molecular emission, revealing new structural features within these sources. W3(OH) shows absorption in a "dusty cocoon" surrounded by molecular emission. These observations also reveal extended emission that is potentially indicative of a low-velocity shock. From the information obtained herein, we have constructed column density and temperature maps for methanol and compared this information to the molecular images. By comparing the spatial distribution of molecules that may be destroyed at later stages of star formation, this work demonstrates the impact of physical environment on chemistry in star-forming regions at different evolutionary stages.

Keywords: Star forming regions, H II regions, Interferometry, Astrochemistry
Morphology of Solar Type II Bursts Caused by Shock Propagation through Turbulent and Inhomogeneous Coronal Plasma. Type II solar bursts are radio signatures of shock waves in the solar corona driven by solar flares or coronal mass ejections (CMEs). Therefore, these bursts present complex spectral morphologies in solar dynamic spectra. Here, we report meter-decameter radio observations of a type II burst on 2014 July 25 made with the Ukrainian radio telescopes UTR-2 (8.25-33 MHz) and GURT (8.25-78 MHz). The burst demonstrates fundamental and harmonic components, band splitting, a herringbone structure, and a spectral break. These specific spectral features, observed jointly in a single type II burst, are rarely detected. To contribute to our understanding of such puzzling type II events, we carried out a detailed analysis of the recorded type II dynamic spectrum. In particular, the herringbone pattern has been exploited to study electron density turbulence in the solar corona. We calculated the power spectral densities of the flux variations in selected herringbones. The spectral index is in the range of α = -1.69 to -2.00 with an average value of -1.897, which is slightly higher than the Kolmogorov spectral index of -5/3 for fully developed turbulence. We also recognized that the second type II burst consists of three drifting lanes. The lane onset times coincide with the spectral break in the first type II burst. We regard that the CME/shock passage through a streamer caused the spectral break and triggered the multilane type II radio emission. Thus, we support one of the proposed scenarios for type II burst occurrence as being the result of CME/shock-streamer interaction.

Keywords: Solar coronal radio emission, Radio bursts, Solar coronal mass ejections, Solar activity, Solar coronal streamers, Solar telescopes
Rapid Variability of the Accretion Disk Wind in the Narrow-line Seyfert 1, PG 1448+273. PG 1448+273 is a luminous, nearby (z = 0.0645), narrow-line Seyfert 1 galaxy, which likely accretes close to the Eddington limit. XMM-Newton observations of PG 1448+273 in 2017 revealed the presence of an ultrafast outflow, as seen through its blueshifted iron K absorption profile, with an outflow velocity of about 0.1 c. Here, the first NuSTAR observation of PG 1448+273, performed in 2022 and coordinated with XMM-Newton, is presented, which shows remarkable variability of its ultrafast outflow. The average count rate is a factor of 2 lower during the last 60 ks of the NuSTAR observation, where a much faster component of the ultrafast outflow was detected with a terminal velocity of 0.26 ± 0.04 c. This is significantly faster than the outflow component that was initially detected in 2017, when overall PG 1448+273 was observed at a lower X-ray flux, and which implies an order of magnitude increase in the wind kinetic power between the 2017 and 2022 epochs. Furthermore, the rapid variability of the ultrafast outflow in 2022, on timescales down to 10 ks, suggests we are viewing through a highly inhomogeneous disk wind in PG 1448+273, where the passage of a denser wind clump could account for the increase in obscuration in the last 60 ks of the NuSTAR observation.

Keywords: Active galaxies, X-ray active galactic nuclei, Quasars
Tidal Spin-up of Black Hole Progenitor Stars. Gravitational wave observations indicate the existence of merging black holes (BHs) with high spin (a ≳ 0.3), whose formation pathways are still an open question. A possible way to form those binaries is through the tidal spin-up of a Wolf–Rayet (WR) star by its BH companion. In this work, we investigate this scenario by directly calculating the tidal excitation of oscillation modes in WR star models, determining the tidal spin-up rate, and integrating the coupled spin–orbit evolution for WR–BH binaries. We find that, for short-period orbits and massive WR stars, the tidal interaction is mostly contributed by standing gravity modes, in contrast to Zahn's model of traveling waves, which is frequently assumed in the literature. The standing modes are less efficiently damped than traveling waves, meaning that prior estimates of tidal spin-up may be overestimated. We show that tidal synchronization is rarely reached in WR–BH binaries, and the resulting BH spins have a ≲ 0.4 for all but the shortest-period (P orb ≲ 0.5 day) binaries. Tidal spin-up in lower-mass systems is more efficient, providing an anticorrelation between the mass and spin of the BHs, which could be tested in future gravitational wave data. Nonlinear damping processes are poorly understood but may allow for more efficient tidal spin-up. We also discuss a new class of gravito-thermal modes that appear in our calculations.

Keywords: Tidal interaction, Wolf-Rayet stars, Stellar oscillations, Astrophysical black holes, Stellar evolution
Optical and Near-infrared Continuum Emission Region Size Measurements in the Lensed Quasar FBQ J0951+2635. We present 10 seasons of Sloan Digital Sky Survey r-band monitoring observations and five seasons of H-band observations of the two-image system FBQ J0951+2635 from the Kaj Strand Astrometric Reflector at the United States Naval Observatory, Flagstaff Station. We supplement our light curves with six seasons of monitoring data from the literature to yield a 10 + 6 season combined data set, which we analyzed with our Monte Carlo microlensing analysis routine to generate constraints on the structure of this system's continuum emission source and the properties of the lens galaxy. Complementing our optical light curves with the five-season near-infrared light curves, we ran a joint Monte Carlo analysis to measure the size of the continuum emission region at both wavelengths, yielding log(r 1/2 cm-1) = ${16.24}_{-0.36}^{+0.33}$ in the r band and ${17.04}_{-0.30}^{+0.26}$ in the H band at rest wavelengths of 2744 and 7254 Å, respectively, correcting for an assumed inclination angle of 60°. Modeling the accretion disk temperature profile as a power law T(r) ∝ r -β , we successfully constrain the slope for FBQ J0951+2635 to $\beta ={0.50}_{-0.18}^{+0.50}$ , shallower than, but nominally consistent with, the predictions of standard thin-disk theory, β = 0.75.

Keywords: Gravitational microlensing, Quasar microlensing, Gravitational lensing, Quasars
Deep Einstein@Home All-sky Search for Continuous Gravitational Waves in LIGO O3 Public Data. We present the results of an all-sky search for continuous gravitational waves in the public LIGO O3 data. The search covers signal frequencies 20.0 Hz ≤ f ≤ 800.0 Hz and a spin-down range down to -2.6 × 10-9 Hz s-1, motivated by detectability studies on synthetic populations of Galactic neutron stars. This search is the most sensitive all-sky search to date in this frequency/spin-down region. The initial search was performed using the first half of the public LIGO O3 data (O3a), utilizing graphical processing units provided in equal parts by the volunteers of the Einstein@Home computing project and by the ATLAS cluster. After a hierarchical follow-up in seven stages, 12 candidates remain. Six are discarded at the eighth stage, by using the remaining O3 LIGO data (O3b). The surviving six can be ascribed to continuous-wave fake signals present in the LIGO data for validation purposes. We recover these fake signals with very high accuracy with our last stage search, which coherently combines all O3 data. Based on our results, we set upper limits on the gravitational-wave amplitude h 0 and translate these into upper limits on the neutron star ellipticity and on the r-mode amplitude. The most stringent upper limits are at 203 Hz, with h 0 = 8.1 × 10-26 at the 90% confidence level. Our results exclude isolated neutron stars rotating faster than 5 ms with ellipticities greater than $5\times {10}^{-8}\left[\tfrac{d}{100\,\mathrm{pc}}\right]$ within a distance d from Earth and r-mode amplitudes $\alpha \geqslant {10}^{-5}\left[\tfrac{d}{100\,\mathrm{pc}}\right]$ for neutron stars spinning faster than 150 Hz.

Keywords: Gravitational wave astronomy, Neutron stars, Gravitational waves
Magnetic Effects Promote Supermassive Star Formation in Metal-enriched Atomic-cooling Halos. Intermediate-mass black holes (with ≥105 M ⊙) are promising candidates for the origin of supermassive black holes (with ~109 M ⊙) in the early universe (redshift z ~ 6). Chon &amp; Omukai first pointed out direct collapse black hole (DCBH) formation in metal-enriched atomic-cooling halos (ACHs), which relaxes the DCBH formation criterion. On the other hand, Hirano et al. showed that magnetic effects promote DCBH formation in metal-free ACHs. We perform a set of magnetohydrodynamical simulations to investigate star formation in magnetized ACHs with metallicities Z/Z ⊙ = 0, 10-5, and 10-4. Our simulations show that the mass accretion rate onto the protostars becomes lower in metal-enriched ACHs than in metal-free ACHs. However, many protostars form from gravitationally and thermally unstable metal-enriched gas clouds. Under such circumstances, the magnetic field rapidly increases as magnetic field lines wind up due to the spin of protostars. The region with the amplified magnetic field expands outwards due to the orbital motion of protostars and the rotation of the accreting gas. The amplified magnetic field extracts angular momentum from the accreting gas, promotes the coalescence of low-mass protostars, and increases the mass growth rate of the primary protostar. We conclude that the magnetic field amplification is always realized in metal-enriched ACHs regardless of the initial magnetic field strength, which affects the DCBH formation criterion. In addition, we find a qualitatively different trend from the previous unmagnetized simulations in that the mass growth rate is maximal for extremely metal-poor ACHs with Z/Z ⊙ = 10-5.

Keywords: Supermassive black holes, Primordial magnetic fields, Protostars, Star formation, Population II stars, Magnetohydrodynamical simulations
The Distribution of Metallicities in the Local Galactic Interstellar Medium. In this investigation, we present an analysis of the metallicity distribution that pertains to neutral gas in the local Galactic interstellar medium (ISM). We derive relative ISM metallicities for a sample of 84 sight lines probing diffuse atomic and molecular gas within 4 kpc of the Sun. Our analysis is based in large part on column density measurements reported in the literature for 22 different elements that are commonly studied in interstellar clouds. We supplement the literature data with new column density determinations for certain key elements and several individual sight lines important to our analysis. Our methodology involves comparing the relative gas-phase abundances of many different elements for a given sight line to simultaneously determine the strength of dust depletion in that direction and the overall metallicity offset. We find that many sight lines probe multiple distinct gas regions with different depletion properties, which complicates the metallicity analysis. Nevertheless, our results provide clear evidence that the dispersion in the metallicities of neutral interstellar clouds in the solar neighborhood is small (~0.10 dex) and only slightly larger than the typical measurement uncertainties. We find no evidence for the existence of very low metallicity gas (as has recently been reported by De Cia et al.) along any of the 84 sight lines in our sample. Our results are consistent with a local Galactic ISM that is well mixed and chemically homogeneous. *Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained from the MAST data archive at the Space Telescope Science Institute. The STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Based in part on data obtained from the ESO Science Archive Facility with DOI: https://doi.org/10.18727/archive/50.

Keywords: Interstellar dust, Interstellar abundances, Interstellar medium, Metallicity, Diffuse interstellar clouds