Sazuna/UAT_keywords huggingface dataset:
On the Nature of AGN and Star Formation Enhancement in the z = 3.1 SSA22 Protocluster: The HST WFC3 IR View. We examine possible environmental sources of the enhanced star formation and active galactic nucleus (AGN) activity in the z = 3.09 SSA22 protocluster using Hubble WFC3 F160W (~1.6 μm) observations of the SSA22 field, including new observations centered on eight X-ray selected protocluster AGN. To investigate the role of mergers in the observed AGN and star formation enhancement, we apply both quantitative (Sérsic-fit and Gini-M20) and visual morphological classifications to F160W images of protocluster Lyman-break galaxies (LBGs) in the fields of the X-ray AGN and z ~ 3 field LBGs in SSA22 and GOODS-N. We find no statistically significant differences between the morphologies and merger fractions of protocluster and field LBGs, though we are limited by small number statistics in the protocluster. We also fit the UV-to-near-IR spectral energy distributions of F160W-detected protocluster and field LBGs to characterize their stellar masses and star formation histories. We find that the mean protocluster LBG is a factor of ~2 times more massive and more attenuated than the mean z ~ 3 field LBG. We take our results to suggest that ongoing mergers are not more common among protocluster LBGs than field LBGs, though protocluster LBGs appear to be more massive. We speculate that the larger mass of the protocluster LBGs contributes to the enhancement of SMBH mass and accretion rate in the protocluster, which in turn drives the observed protocluster AGN enhancement.

Keywords: High-redshift galaxy clusters, Active galactic nuclei, X-ray active galactic nuclei, Galaxy mergers, High-redshift galaxies
Radial Migration from the Metallicity Gradient of Open Clusters and Outliers. Radial migration is an important process in the evolution of the Galactic disk. The metallicity gradient of open clusters and its outliers provide an effective way to examine this process. In this work, we compile metallicity, age, and kinematic parameters for 225 open clusters and carry out a quantitative analysis of radial migration via the calculated migration distances. Based on clusters with age &lt;0.5 Gyr, we obtain a present-day metallicity gradient of -0.074 ± 0.007 dex kpc-1. Three sequences are distributed along this gradient, and clusters in the upper, middle, and lower groups are found to be old outward migrators, in situ clusters, and inward migrators, respectively. The migration distance increases with age, but the time when it is most effective is probably less than 3 Gyr. The metallicity gradient breaks at guiding center radius Rg ~ 11.5 kpc, which is caused by the lack of young open clusters in the outer disk and the presence of old outward migrators in the upper sequence. This shows that this boundary is related to the different effects of radial migration between the inner and outer disks. We also found many special open clusters in and near the outer disk with R &gt; 11 kpc and a steeper metallicity gradient from the inner disk of Rg &lt; 7 kpc, which tells of a complicated evolution history of the Galactic disk caused by different effects of stellar radial migration.

Keywords: Stellar kinematics, Solar neighborhood, Galaxy disks, Galaxy abundances, Galaxy evolution, Open star clusters
The Origin of Parity Violation in Polarized Dust Emission and Implications for Cosmic Birefringence. Recent measurements of Galactic polarized dust emission have found a nonzero TB signal, a correlation between the total intensity and the B-mode polarization component. We present evidence that this parity-odd signal is driven by the relative geometry of the magnetic field and the filamentary interstellar medium in projection. Using neutral hydrogen morphology and Planck polarization data, we find that the angle between intensity structures and the plane-of-sky magnetic field orientation is predictive of the signs of Galactic TB and EB. Our results suggest that magnetically misaligned filamentary dust structures introduce nonzero TB and EB correlations in the dust polarization, and that the intrinsic dust EB can be predicted from measurements of dust TB and TE over the same sky mask. We predict correlations between TE, TB, EB, and EE/BB, and confirm our predictions using synthetic dust polarization maps from magnetohydrodynamic simulations. We introduce and measure a scale-dependent effective magnetic misalignment angle, ${\psi }_{{\ell }}^{\mathrm{dust}}\sim 5^\circ $ for 100 ≲ ℓ ≲ 500, and predict a positive intrinsic dust EB with amplitude $\left\langle {D}_{{\ell }}^{{EB}}\right\rangle \lesssim 2.5\,\mu {{\rm{K}}}_{\mathrm{CMB}}^{2}$ for the same multipole range at 353 GHz over our sky mask. Both the sign and amplitude of the Galactic EB signal can change with the sky area considered. Our results imply that searches for parity violation in the cosmic microwave background must account for the nonzero Galactic EB and TB signals, necessitating revision of existing analyses of the evidence for cosmic birefringence.

Keywords: Cosmology, Interstellar dust, Interstellar filaments, Interstellar atomic gas, Milky Way magnetic fields, Astrophysical magnetism, Cosmic microwave background radiation, Neutral hydrogen clouds, Interstellar magnetic fields, Dust continuum emission, Interstellar medium, Magnetic fields
Lessons from the First Multiply Imaged Supernova: Revised Strong-lensing Models for the Galaxy Cluster MACS J1149.5+2223. We present two grid-based lens models for the galaxy cluster MACS J1149.5+2223, concentrating on the properties of the first multiply imaged supernova Refsdal, which first appeared in this cluster as an Einstein cross (images S1-S4) around a cluster galaxy in late 2014, and about a year later as an additional image (SX) in a different image of the supernova (SN) host galaxy. One model is our updated light-traces-mass (LTM) strong-lensing model for this cluster, and the second is a parametric model (dPIEeNFW), generated using the same pipeline but with a different parameterization. Together these two models probe different possible solutions in a relatively self-consistent manner and can be used to examine systematic uncertainties and relevant differences between the two parameterizations. We obtain reasonably similar (agreeing to within ≃1σ-3σ, in most cases) time delays and magnification ratios, with respect to S1, from the two different methods, although the LTM predictions seem to be systematically shorter/smaller for some of the images. Most notably, the time delay [and 95% CI] between the Einstein cross (in particular, image S1), and SX, differs substantially between the parametric method (326 [300-359] days) and the LTM method (224 [198-306] days), which seems to underestimate the true reappearance time. The cause for this systematic difference is unclear at present. We speculate on its possible origin and note that a refined measurement of SN Refsdal's properties should help to more strongly discriminate between the two solutions, and thus between the two descriptions for the intrinsic shape of the underlying matter distribution. We also discuss the implications of our results for the Hubble constant.

Keywords: Cosmology, Galaxy clusters, Cosmological parameters, Strong gravitational lensing, Observational cosmology, Navarro-Frenk-White profile, Hubble constant, Gravitational lensing, Dark matter
Misaligned Circumstellar Disks and Orbital Motion of the Young Binary XZ Tau. We report our analyses of the multi-epoch (2015-2017) Atacama Large Millimeter/submillimeter Array (ALMA) archival data of the Class II binary system XZ Tau at Bands 3, 4, and 6. The millimeter dust-continuum images show compact, unresolved (r ≲ 15 au) circumstellar disks (CSDs) around the individual binary stars, XZ Tau A and B, with a projected separation of ~39 au. The 12CO (2-1) emission associated with those CSDs traces the Keplerian rotations, whose rotational axes are misaligned with each other (P.A. ~ -5° for XZ Tau A and ~130° for XZ Tau B). The similar systemic velocities of the two CSDs (VLSR ~ 6.0 km s-1) suggest that the orbital plane of the binary stars is close to the plane of the sky. From the multi-epoch ALMA data, we have also identified the relative orbital motion of the binary. Along with the previous NIR data, we found that the elliptical orbit (e = ${0.742}_{-0.034}^{+0.025}$ , $a=0\buildrel{\prime\prime}\over{.} {172}_{-0\buildrel{\prime\prime}\over{.} 003}^{+0\buildrel{\prime\prime}\over{.} 002}$ , and $\omega =-54\buildrel{\circ}\over{.} {2}_{-4\buildrel{\circ}\over{.} 7}^{+2\buildrel{\circ}\over{.} 0}$ ) is preferable to the circular orbit. Our results suggest that the two CSDs and the orbital plane of the XZ Tau system are all misaligned with each other, and possible mechanisms to produce such a configuration are discussed. Our analyses of the multi-epoch ALMA archival data demonstrate the feasibility of time-domain science with ALMA.

Keywords: Star formation, Binary stars
A Disk and No Signatures of Tidal Distortion in the Galaxy "Lacking" Dark Matter NGC 1052-DF2. Using ultra-deep imaging (μg = 30.4 mag arcsec-2; 3σ, 10″ × 10″), we probed the surroundings of the first galaxy "lacking" dark matter (DM) KKS2000[04] (NGC 1052-DF2). Signs of tidal stripping in this galaxy would explain its claimed low content of DM. However, we find no evidence of tidal tails. In fact, the galaxy remains undisturbed down to a radial distance of 80″. This radial distance triples previous spatial explorations of the stellar distribution of this galaxy. In addition, the distribution of its globular clusters (GCs) is not extended in relation to the bulk of the galaxy (the radius containing half of the GCs is 21″). We also found that the surface brightness radial profiles of this galaxy in the g and r bands decline exponentially from 35″ to 80″. Together with a constant ellipticity and position angle in the outer parts of the galaxy, this strongly suggests the presence of a low-inclination disk. This is consistent with the evidence of rotation found for this object. This finding implies that the dynamical mass of this galaxy is a factor of 2 higher than previously reported, which brings the DM content of this galaxy in line with galaxies of similar stellar mass.

Keywords: Galaxy formation, Dark matter, Low surface brightness galaxies
ZFIRE: The Beginning of the End for Massive Galaxies at z   2 and Why Environment Matters. We use ZFIRE and ZFOURGE observations with the spectral energy distribution fitting tool PROSPECTOR to reconstruct the star formation histories (SFHs) of protocluster and field galaxies at z ~ 2 and compare our results to the TNG100 run of the IllustrisTNG cosmological simulation suite. In the observations, we find that massive protocluster galaxies ( $\mathrm{log}[{M}_{* }/{M}_{\odot }]$ &gt; 10.5) form 45% ± 8% of their total stellar mass in the first 2 Gyr of the universe, compared to 31% ± 2% formed in the field galaxies. In both observations and simulations, massive protocluster galaxies have a flat/declining SFH with decreasing redshift compared to rising SFH in their field counterparts. Using IllustrisTNG, we find that massive galaxies ( $\mathrm{log}[{M}_{* }/{M}_{\odot }]\geqslant 10.5$ ) in both environments are on average ≈190 Myr older than low-mass galaxies ( $\mathrm{log}[{M}_{* }/{M}_{\odot }]=9\mbox{--}9.5$ ). However, the difference in mean stellar ages of cluster and field galaxies is minimal when considering the full range in stellar mass ( $\mathrm{log}[{M}_{* }/{M}_{\odot }]\geqslant 9$ ). We explore the role of mergers in driving the SFH in IllustrisTNG and find that massive cluster galaxies consistently experience mergers with low gas fraction compared to other galaxies after 1 Gyr from the big bang. We hypothesize that the low gas fraction in the progenitors of massive cluster galaxies is responsible for the reduced star formation.

Keywords: Hydrodynamical simulations, High-redshift galaxy clusters, Galaxy environments, Star formation, Galaxy evolution
A Quasi-periodic Oscillation in the γ-Ray Emission from the Non-blazar Active Galactic Nucleus PKS 0521-36. Long-term γ-ray variability of a non-blazar Active Galactic Nucleus PKS 0521-36 is investigated by using Fermi Large Area Telescope (Fermi-LAT) pass 8 data covering from 2008 August to 2021 March. The results show that the histogram of the γ-ray fluxes follows a log-normal distribution. Interestingly, in the analysis of ~5.8 yr (from MJD 56317-58447) LAT data between two outbursts (occurring during 2012 October and 2019 May respectively), a quasi-periodic oscillation (QPO) with a period of ~1.1 yr (~5σ of significance) is found in the Lomb-Scargle Periodogram (LSP), the Weighted Wavelet Z-transform, and the REDFIT results. This quasiperiodic signal also appears in the results of Gaussian process modeling the light curve. Therefore, the robustness of the QPO is examined by four different methods. This is the first γ-ray QPO found in a mildly beamed jet. Our results imply that the γ-ray outbursts play an important role in the formation of the γ-ray QPO.

Keywords: Jets, Period search , Active galactic nuclei, Gamma-rays, Time series analysis
Gamma-Ray Emission Produced by r-process Elements from Neutron Star Mergers. The observation of a radioactively powered kilonova AT 2017gfo associated with the gravitational wave event GW170817 from a binary neutron star merger proves that these events are ideal sites for the production of heavy r-process elements. The gamma-ray photons produced by the radioactive decay of heavy elements are unique probes for the detailed nuclide compositions. Based on the detailed r-process nucleosynthesis calculations and considering radiative transport calculations for the gamma rays in different shells, we study the gamma-ray emission in a merger ejecta on a timescale of a few days. It is found that the total gamma-ray energy generation rate evolution is roughly depicted as $\dot{E}\propto {t}^{-1.3}$ . For the dynamical ejecta with a low electron fraction (Ye ≲ 0.20), the dominant contributors of gamma-ray energy are the nuclides around the second r-process peak (A ~ 130) and the decay chain of 132Te (t1/2 = 3.21 days) → 132I (t1/2 = 0.10 days) → 132Xe produces gamma-ray lines at 228, 668, and 773 keV. For the case of a wind ejecta with Ye ≳ 0.30, the dominant contributors of gamma-ray energy are the nuclides around the first r-process peak (A ~ 80) and the decay chain of 72Zn (t1/2 = 1.93 days) → 72Ga (t1/2 = 0.59 days) → 72Ge produces gamma-ray lines at 145, 834, 2202, and 2508 keV. The peak fluxes of these lines are 10-9 ~ 10-7 ph cm-2 s-1, which are marginally detectable with the next-generation MeV gamma-ray detector ETCC if the source is at a distance of 40 Mpc.

Keywords: Gamma-ray bursts, Explosive nucleosynthesis, Gravitational wave sources
On the Origin of Switchbacks Observed in the Solar Wind. The origin of switchbacks in the solar wind is discussed in two classes of theory that differ in the location of the source being either near the transition region near the Sun or in the solar wind itself. The two classes of theory differ in their predictions of the switchback rate (the number of switchbacks observed per hour) as a function of distance from the Sun. To distinguish between these theories, one-hour averages of Parker Solar Probe data were averaged over five orbits to find the following: (1) The hourly averaged switchback rate was independent of distance from the Sun. (2) The average switchback rate increased with solar wind speed. (3) The switchback size perpendicular to the flow increased as R, the distance from the Sun, while the radial size increased as R2, resulting in an increasing switchback aspect ratio with distance from the Sun. (4) The hourly averaged and maximum switchback rotation angles did not depend on the solar wind speed or distance from the Sun. These results are consistent with switchback formation in the transition region because their increase of tangential size with radius compensates for the radial falloff of their equatorial density to produce switchback rates that are independent of radial distance. This constant switchback rate is inconsistent with an in situ source. The switchback size and aspect ratio, but not their hourly average or maximum rotation angle, increased with radial distance to 100 solar radii. Additionally, quiet intervals between switchback patches occurred at the lowest solar wind speeds.

Keywords: Space plasmas, Solar wind, Solar corona
Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). XIV. A Candidate Type II Quasar at z = 6.1292. We present deep Keck/MOSFIRE near-infrared spectroscopy of a strong Lyα emitting source at z = 6.1292, HSC J142331.71-001809.1, which was discovered by the SHELLQS program from imaging data of the Subaru Hyper Suprime-Cam (HSC) survey. This source is one of five objects that show narrow (FWHM &lt; 500 km s-1) and prominent (LLyα &gt; 1044 erg s-1) Lyα emission lines at absolute 1450 Å continuum magnitudes of M1450 ~ -22 mag. Its rest-frame Lyα equivalent width (EW) is 370 ± 30 Å. In the 2 hr Keck/MOSFIRE spectrum in Y band, the high-ionization C IV λλ1548,1550 doublet emission line was clearly detected with $\mathrm{FWHM}={120}_{-20}^{+20}$ km s-1 and a total rest-frame EW of ${37}_{-5}^{+6}$ Å. We also report the detection of weak continuum emission, and the tentative detection of O III]λλ1661,1666 in the 4 hr J-band spectrum. Judging from the UV magnitude, line widths, luminosities, and EWs of Lyα and C IV, we suggest that this source is a reionization-era analog of classical type-II AGNs, although there is a possibility that it represents a new population of AGN/galaxy composite objects in the early universe. We compare the properties of J1423-0018 to intermediate-redshift type-II AGNs and C IV emitters seen in z = 6-7 galaxy samples. Further observations of other metal emission lines in the rest-frame UV or optical, along with X-ray follow-up observations of the z = 6-7 narrow-line quasars, are needed for more robust diagnostics and to determine their nature.

Keywords: Quasars
Orientation and Accretion in a Representative Sample of Active Galactic Nuclei. We highlight a representative sample of active galactic nuclei selected independent of orientation. The defining characteristic of the selection is sophisticated matching between the 0.1 &lt; z &lt; 0.6 Sloan Digital Sky Survey quasars from the Seventh Data Release to the Westerbork Northern Sky Survey at 325 MHz and the subsequent application of a spatially integrated radio spectral luminosity density cut. The resulting sample is complete down to the limiting luminosity and unbiased by orientation. Compared to orientation samples in the literature this approach yields less bias with redshift, relatively more lobe-dominated sources including those with radio lobes and no visible core, and a distribution of radio core dominance that is consistent with expectations from a uniform distribution of inclinations with solid angle. We measure properties of the optical spectra, and use the sample to investigate the orientation dependence of the velocity width of the broad Hβ emission line. We recover the known orientation dependence, but the sharp envelope of previous studies where only edge-on sources display the broadest lines, is absent. Scatter in this diagram is not attributable solely to black hole mass, Eddington ratio, or contamination in the sample from compact steep-spectrum sources. A physical framework for quasar beaming and a disk-like broad-line region can describe the representative sample when it is expanded to include additional parameters, in particular jet properties and the broad-line region velocity field. These points serve to illustrate the critical role of sample selection in the interpretation of observable properties as indicators of physical parameters of quasar central engines.

Keywords: Radio loud quasars, Radio active galactic nuclei, Surveys, Quasars
Radial Gradients in Dust-to-gas Ratio Lead to Preferred Region for Giant Planet Formation. The Rosseland mean opacity of dust in protoplanetary disks is often calculated assuming the interstellar medium (ISM) size distribution and a constant dust-to-gas ratio. However, the dust size distribution and dust-to-gas ratio in protoplanetary disks are distinct from those of the ISM. Here we use simple dust evolution models that incorporate grain growth and transport to calculate the time evolution of the mean opacity of dust grains as a function of distance from the star. Dust dynamics and size distribution are sensitive to the assumed value of the turbulence strength αt and the velocity at which grains fragment vfrag. For moderate-to-low turbulence strengths of αt ≲ 10-3 and substantial differences in vfrag for icy and ice-free grains, we find a spatially nonuniform dust-to-gas ratio and grain size distribution that deviate significantly from the ISM values, in agreement with previous studies. The effect of a nonuniform dust-to-gas ratio on the Rosseland mean opacity dominates over that of the size distribution. This spatially varying-that is, non-monotonic-dust-to-gas ratio creates a region in the protoplanetary disk that is optimal for producing hydrogen-rich planets, potentially explaining the apparent peak in the gas-giant planet occurrence rate at intermediate distances. The enhanced dust-to-gas ratio within the ice line also suppresses gas accretion rates onto sub-Neptune cores, thus stifling their tendency to undergo runaway gas accretion within disk lifetimes. Finally, our work corroborates the idea that low-mass cores with large primordial gaseous envelopes ("super-puffs") originate beyond the ice line.

Keywords: Gas-to-dust ratio, Protoplanetary disks, Mini Neptunes, Extrasolar gaseous giant planets, Planet formation
Variability of Disk Emission in Pre-main Sequence and Related Stars. V. Occultation Events from the Innermost Disk Region of the Herbig Ae Star HD 163296. HD 163296 is a Herbig Ae star that underwent a dramatic ~0.8 magnitude drop in brightness in the V photometric band in 2001 and a brightening in the near-IR in 2002. Because the star possesses Herbig-Haro objects traveling in outflowing bipolar jets, it was suggested that the drop in brightness was due to a clump of dust entrained in a disk wind, blocking the line of sight toward the star. In order to quantify this hypothesis, we investigated the brightness drop at visible wavelengths and the brightening at near-IR wavelengths of HD 163296 using the Monte Carlo Radiative Transfer Code, HOCHUNK3D. We created three models to understand the events. Model 1 describes the quiescent state of the system. Model 2 describes the change in structure that led to the drop in brightness in 2001. Model 3 describes the structure needed to produce the observed 2002 brightening of the near-IR wavelengths. Models 2 and 3 utilize a combination of a disk wind and central bipolar flow. By introducing a filled bipolar cavity in Models 2 and 3, we were able to successfully simulate a jet-like structure for the star with a disk wind and created the drop and subsequent increase in brightness of the system. On the other hand, when the bipolar cavity is not filled, Model 1 replicates the quiescent state of the system.

Keywords: Protoplanetary disks, Circumstellar disks