Sazuna/UAT_keywords huggingface dataset:
NGC 5128 Globular Cluster Candidates Out to 150 kpc: A Comprehensive Catalog from Gaia and Ground-based Data. We present a new catalog of 40,502 globular cluster (GC) candidates in NGC 5128 out to a projected radius of ~150 kpc based on data from the Panoramic Imaging Survey of Centaurus and Sculptor, the Gaia Data Release 2, and the NOAO Source Catalog. Ranking these candidates based on the likelihood that they are true GCs, we find that approximately 1900 belong to our top two ranking categories and should be the highest priority for spectroscopic follow-up for confirmation. Taking into account our new data and a vetting of previous GC catalogs, we estimate a total GC population of 1450 ± 160 GCs. We show that a substantial number of sources previously argued to be low-velocity GCs are instead foreground stars, reducing the inferred GC velocity dispersion. This work showcases the power of Gaia to identify slightly extended sources at the ~4 Mpc distance of NGC 5128, enabling accurate identification of GCs throughout the entire extended halo, not just the inner regions that have been the focus of most previous work. * This paper includes data gathered with the 6.5 m Magellan Telescope at Las Campanas Observatory, Chile.

Keywords: Globular star clusters, Optical identification, Galaxy evolution
KCWI Observations of the Extended Nebulae in Mrk 273. Ultraluminous infrared galaxies (ULIRGs) represent a critical stage in the merger-driven evolution of galaxies when active galactic nucleus (AGN) activity is common and AGN feedback is expected. We present high-sensitivity and large field-of-view integral field spectroscopy of the ULIRG Mrk 273 using new data from the Keck Cosmic Web Imager (KWCI). The KCWI data capture the complex nuclear region and the two extended nebulae in the northeast (NE) and southwest (SW) to ~20 kpc scales. Kinematics in the nuclear region show a fast, extended, bipolar outflow in the direction of the previously reported nuclear superbubbles spanning ~5 kpc, two to three times greater than the previously reported size. The larger-scale extended nebulae on ~20 kpc show fairly uniform kinematics with FWHM ~ 300 km s-1 in the SW nebula and FWHM ~ 120 km s-1 in the NE nebula. We detect for the first time high-ionization [Ne V] 3426, [O III] 4363, and He II 4684 emission lines in the extended NE nebula. Emission line ratios in the nuclear region correlate with the kinematic structures, with the bipolar outflow and the less collimated "outflow regions" showing distinct line ratio trends. Line ratio diagnostics of high-ionization emission lines reveal a nontrivial contribution from shock plus precursor ionization in the NE nebula and the nuclear region mixed with AGN photoionization. These data are highly constraining for models of cool ionized gas existing 20 kpc from a galactic nucleus.

Keywords: Galactic winds, Markarian galaxies, Active galaxies, Galaxy evolution, Ultraluminous infrared galaxies
Gaia EDR3 Parallax Distances to the Great Carina Nebula and Its Star Clusters (Trumpler 14, 15, 16). Using offset-corrected Gaia EDR3 parallax measurements and spectrophotometric methods, we have determined distances for 69 massive stars in the Carina OB1 association and associated clusters: Trumpler 16 (21 stars), Trumpler 14 (20 stars), Trumpler 15 (three stars), Bochum 11 (five stars), and South Pillars region (20 stars). Past distance estimates to the Carina Nebula range from 2.2 to 3.6 kpc, with uncertainties arising from photometry and anomalous dust extinction. The EDR3 parallax solutions show considerable improvement over DR2, with typical errors σϖ/ϖ ≈ 3%-5%. The O-type stars in the Great Carina Nebula lie at essentially the same distance (2.35 ± 0.08 kpc), quoting mean and rms variance. The clusters have distances of 2.32 ± 0.12 kpc (Tr 16), 2.37 ± 0.15 kpc (Tr 14), 2.36 ± 0.09 kpc (Tr 15), and 2.33 ± 0.12 kpc (Bochum 11) in good agreement with the η Car distance of around 2.3 kpc. O-star proper motions suggest internal (3D) velocity dispersions ~4 km s-1 for Tr 14 and Tr 16. Reliable distances allow estimates of cluster sizes, stellar dynamics, luminosities, and fluxes of photoionizing radiation incident on photodissociation regions in the region. We estimate that Tr 14 and Tr 16 have half-mass radii rh = 1.5-1.8 pc, stellar crossing times tcr = rh/vm ≈ 0.7-0.8 Myr, and two-body relaxation times trh ≈ 40-80 Myr. The underlying velocity dispersion for Tr 14, if a bound cluster, would be ${v}_{{\rm{m}}}\approx {2.1}_{-0.4}^{+0.7}$ km s-1 for $N={7600}_{-2600}^{+5800}$ stars. With the higher dispersions of the O stars, inward drift would occur slowly, on timescales of 3-6 Myr.

Keywords: Parallax, Massive stars, Stellar dynamics, Stellar parallax, Open star clusters
The MOSDEF Survey: The Evolution of the Mass-Metallicity Relation from z = 0 to z 3.3. We investigate the evolution of galaxy gas-phase metallicity (O/H) over the range z = 0-3.3 using samples of ~300 galaxies at z ~ 2.3 and ~150 galaxies at z ~ 3.3 from the MOSDEF survey. This analysis crucially utilizes different metallicity calibrations at z ~ 0 and z &gt; 1 to account for evolving interstellar medium (ISM) conditions. We find significant correlations between O/H and stellar mass (M*) at z ~ 2.3 and z ~ 3.3. The low-mass power-law slope of the mass-metallicity relation (MZR) is remarkably invariant over z = 0-3.3, such that O/H ∝ ${M}_{* }^{0.30}$ at all redshifts in this range. At fixed M*, O/H decreases with increasing redshift as dlog(O/H)/dz = -0.11 ± 0.02. We find no evidence that the fundamental metallicity relation between M*, O/H, and star formation rate evolves out to z ~ 3.3. We employ analytic chemical evolution models to place constraints on the mass and metal loading factors of galactic outflows. The efficiency of metal removal increases toward lower M* at fixed redshift and toward higher redshift at fixed M*. These models suggest that the slope of the MZR is primarily set by the scaling of the outflow metal loading factor with M*, not by the change in gas fraction as a function of M*. The evolution toward lower O/H at fixed M* with increasing redshift is driven by both higher gas fraction (leading to stronger dilution of ISM metals) and higher metal removal efficiency. These results suggest that the processes governing the smooth baryonic growth of galaxies via gas flows and star formation hold in the same form over at least the past 12 Gyr. * Based on data obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W.M. Keck Foundation.

Keywords: Metallicity, Galaxy chemical evolution, Chemical abundances, Emission line galaxies, Galaxy abundances, Galaxy winds, Galaxy evolution, High-redshift galaxies
Globular Cluster Systems of Massive Compact Elliptical Galaxies in the Local Universe: Evidence for Relic Red Nuggets?. Nearby massive compact elliptical galaxies (MCEGs) are strong candidates for relic galaxies (i.e., local analogs of red nuggets at high redshifts). It is expected that the globular cluster (GC) systems of relic galaxies are dominated by red (metal-rich) GCs. NGC 1277 is known as a unique example of such a galaxy in the previous study. In this study, we search for GCs in 12 nearby MCEGs at distances of ≲100 Mpc from the Hubble Space Telescope/Wide Field Camera 3 F814W(I814)/F160W(H160) archival images. We find that most of these MCEGs host a rich population of GCs with a color range of $0.0\lt {({I}_{814}-{H}_{160})}_{0}\lt 1.1$ . The fractions of their red GCs range from fRGC = 0.2 to 0.7 with a mean of fRGC = 0.48 ± 0.14. We divide the MCEG sample into two groups: one in clusters and the other in groups/fields. The mean red GC fraction of the cluster MCEGs is 0.60 ± 0.06, which is 0.2 larger than the value of the group/field MCEGs, 0.40 ± 0.10. The value for the cluster MCEGs is ~0.3 larger than the mean value of giant early-type galaxies with similar stellar mass in the Virgo Cluster (fRGC = 0.33 ± 0.13). Our results show that most of the MCEGs in our sample are indeed relic galaxies. This further implies that a majority of the red GCs in MCEGs are formed early in massive galaxies and that most MCEGs in the local universe have rarely undergone mergers after they became red nuggets about 10 Gyr ago.

Keywords: Globular star clusters, Elliptical galaxies, Galaxy evolution, Compact galaxies
Modeling Stellar Ca II H and K Emission Variations. I. Effect of Inclination on the S-index. The emission in the near-ultraviolet Ca II H and K lines is modulated by stellar magnetic activity. Although this emission, quantified via the S-index, has been serving as a prime proxy of stellar magnetic activity for several decades, many aspects of the complex relation between stellar magnetism and Ca II H and K emission are still unclear. The amount of measured Ca II H and K emission is suspected to be affected not only by the stellar intrinsic properties but also by the inclination angle of the stellar rotation axis. Until now, such an inclination effect on the S-index has remained largely unexplored. To fill this gap, we develop a physics-based model to calculate S-index, focusing on the Sun. Using the distributions of solar magnetic features derived from observations together with Ca II H and K spectra synthesized in non-local thermodynamic equilibrium, we validate our model by successfully reconstructing the observed variations of the solar S-index over four activity cycles. Further, using the distribution of magnetic features over the visible solar disk obtained from surface flux transport simulations, we obtain S-index time series dating back to 1700 and investigate the effect of inclination on S-index variability on both the magnetic activity cycle and the rotational timescales. We find that when going from an equatorial to a pole-on view, the amplitude of S-index variations decreases weakly on the activity cycle timescale and strongly on the rotational timescale (by about 22% and 81%, respectively, for a cycle of intermediate strength). The absolute value of the S-index depends only weakly on the inclination. We provide analytical expressions that model such dependencies.

Keywords: Plages, Stellar chromospheres, Sunspots, Stellar activity, Solar faculae, Radiative transfer
Caltech-NRAO Stripe 82 Survey (CNSS). V. AGNs That Transitioned to Radio-loud State. A recent multiyear Caltech-NRAO Stripe 82 Survey revealed a group of objects that appeared as new radio sources after &gt;5-20 yr of absence. They are transient phenomena with respect to the Faint Images of the Radio Sky at Twenty Centimeters survey and constitute the first unbiased sample of renewed radio activity. Here we present a follow-up, radio, optical, and X-ray study of them. The group consists of 12 sources, both quasars and galaxies with wide redshift (0.04 &lt; z &lt; 1.7) and luminosity ( $22\lt {\mathrm{log}}_{10}[{L}_{1.4\mathrm{GHz}}/{\rm{W}}\,{\mathrm{Hz}}^{-1}]\gt 24.5$ ) distributions. Their radio properties in the first phase of activity, namely the convex spectra and compact morphology, allow them all to be classified as gigahertz-peaked spectrum (GPS) sources. We conclude that the spectral changes are a consequence of the evolution of newly born radio jets. Our observations show that over the next few years of activity the GPS galaxies keep the convex shape of the spectrum, while GPS quasars rapidly transform into flat-spectrum sources, which may result in them not being recognized as young sources. The wide range of bolometric luminosities, black hole masses, and jet powers among the transient sources indicates even greater population diversity in the group of young radio objects. We also suggest that small changes of the accretion disk luminosity (accretion rate) may be sufficient to ignite low-power radio activity that evolves on the scale of decades.

Keywords: AGN host galaxies, Supermassive black holes, Quasars, Active galaxies, Radio quiet quasars, Radio loud quasars, Radio galaxies, Active galactic nuclei, Galaxy evolution
Hit-and-stick Dust Collisions: Rotating Aggregate Targets. Current models of dust aggregation in early planet formation describe numerous collision mechanisms in detail, but this research evaluates the impact of an idea that has not yet been explored: the effect of rotating targets on the probability of aggregate growth. Rotating target surfaces decrease the probability of successful sticking collisions due to an increased relative velocity between the colliding surfaces. A model has been developed to quantify this effect for use in dust evolution models. Curiously, the decrease in probability was found to almost exactly correlate to a quadratic function of the target angular velocity. For the range of target angular velocities between 0 and 100 rad s-1, the decrease in probability of sticking was calculated to be between 0% and 25% lower than predicted in a model that does not consider rotation, suggesting that dust may accumulate slower than previously thought in streaming stabilities.

Keywords: Planetary system formation, Protoplanetary disks
The Strength and Structure of the Magnetic Field in the Galactic Outflow of Messier 82. Galactic outflows driven by starbursts can modify the galactic magnetic fields and drive them away from the galactic planes. Here, we quantify how these fields may magnetize the intergalactic medium (IGM). We estimate the strength and structure of the fields in the starburst galaxy M82 using thermal polarized emission observations from the Stratospheric Observatory for Infrared Astronomy/High-resolution Airborne Wideband Camera-plus and a potential field extrapolation commonly used in solar physics. We modified the Davis-Chandrasekhar-Fermi method to account for the large-scale flow and the turbulent field. Results show that the observed magnetic fields arise from the combination of a large-scale ordered potential field associated with the outflow and a small-scale turbulent field associated with bow-shock-like features. Within the central 900 pc radius, the large-scale field accounts for 53 ± 4% of the observed turbulent magnetic energy with a median field strength of 305 ± 15 μG, while small-scale turbulent magnetic fields account for the remaining 40 ± 5% with a median field strength of 222 ± 19 μG. We estimate that the turbulent kinetic and turbulent magnetic energies are in close equipartition up to ~2 kpc (measured), while the turbulent kinetic energy dominates at ~7 kpc (extrapolated). We conclude that the fields are frozen into the ionized outflowing medium and driven away kinetically. The magnetic field lines in the galactic wind of M82 are open, providing a direct channel between the starburst core and the IGM. Our novel approach offers the tools needed to quantify the effects of outflows on galactic magnetic fields as well as their influence on the IGM and evolution of energetic particles.

Keywords: Starburst galaxies, Solar physics, Polarimetry, Extragalactic magnetic fields
Magnetically Regulated Disk Formation in the Inner 100 au Region of the Class 0 Young Stellar Object OMC-3/MMS 6 Resolved by JVLA and ALMA. We have carried out polarization calibration for archival Jansky Very Large Array (JVLA) (~9 mm) full polarization observations toward the Class 0 young stellar object (YSO) OMC-3/MMS 6 (also known as HOPS-87), and then compared the results with the archival Atacama Large Millimeter Array (ALMA) 1.2 mm observations. The resolved spectral indices show that the innermost ~100 au region of OMC-3/MMS 6 is marginally optically thin (e.g., τ ≲ 1) at ~9 mm wavelength, such that the JVLA observations can directly probe the linearly polarized emission from nonspherical dust. Assuming that the projected long axis of dust grains is aligned perpendicular to magnetic field (B-field) lines, we propose that the overall B-field topology resembles an hourglass shape. The geometry of this system is consistent with a magnetically regulated dense (pseudo)disk, although this "hourglass" appears to be ~40° inclined with respect to the previously reported outflow axis. In contrast, the inner ~100 au region of this YSO is likely very optically thick (e.g., τ ≫ 1) at ~1 mm wavelength. The electric field position angles resolved by JVLA and ALMA present ~90° offsets on this region, which indicate that the dominant polarization mechanism at 1 mm wavelength is dichroic extinction. This is the second case where the (sub)millimeter dichroic extinction is demonstrated by the direct comparison between the JVLA and ALMA polarization observations.

Keywords: Interstellar magnetic fields, Young stellar objects, Polarimetry, Circumstellar grains
Microscale Processes Determining Macroscale Evolution of Magnetic Flux Tubes along Earth's Magnetopause. An important process affecting solar wind-Earth's magnetosphere coupling is nonsteady dayside magnetic reconnection, observationally evidenced by a flux transfer event (FTE) that shows a bipolar variation of the magnetic field component normal to the magnetopause. FTEs often consist of two interlinked flux tubes, but, local kinetic processes between the flux tubes are not understood in the context of the FTE structuring, evolution, and impact. An FTE observed by the Magnetospheric Multiscale mission on 2017 December 18 consisted of two flux tubes of different topology. One includes field lines with ends connected to the northern and southern hemispheres while the other includes field lines with both ends connected to the magnetosheath. Reconnection occurring at the flux-tube interface indicates how interacting flux tubes evolve into a flux rope with helical magnetic topology that is either closed or open. This study demonstrates a new aspect of how micro- to meso-scale dynamics occurring within FTEs determines their macroscale characteristics and evolution.

Keywords: Solar-planetary interactions, Solar system terrestrial planets, Solar system, Solar-terrestrial interactions, Planetary magnetospheres
GASP. XXXIII. The Ability of Spatially Resolved Data to Distinguish among the Different Physical Mechanisms Affecting Galaxies in Low-density Environments. Galaxies inhabit a wide range of environments and therefore are affected by different physical mechanisms. Spatially resolved maps combined with the knowledge of the hosting environment are very powerful for classifying galaxies by physical process. In the context of the GAs Stripping Phenomena in galaxies (GASP), we present a study of 27 non-cluster galaxies: 24 of them were selected for showing asymmetries and disturbances in the optical morphology, suggestive of gas stripping; 3 of them are passive galaxies and were included to characterize the final stages of galaxy evolution. We therefore provide a panorama of the different processes taking place in low-density environments. The analysis of VLT/MUSE data allows us to separate galaxies into the following categories: galaxy-galaxy interactions (2 galaxies), mergers (6), ram pressure stripping (4), cosmic web stripping (2), cosmic web enhancement (5), gas accretion (3), and starvation (3). In one galaxy we identify the combination of merger and ram pressure stripping. Only 6/27 of these galaxies have just a tentative classification. We then investigate where these galaxies are located on scaling relations determined for a sample of undisturbed galaxies. Our analysis shows the successes and limitations of a visual optical selection in identifying the processes that deplete galaxies of their gas content and probes the power of IFU data in pinning down the acting mechanism.

Keywords: Galaxy formation, Stellar kinematics, Star formation, Galaxy groups, Galaxy evolution, Field galaxies, Galaxies
The G 305 Star-forming Region. II. Irregular Variable Stars. We present a catalog of 167 newly discovered, irregular variables spanning a ~7 deg2 area that encompasses the G 305 star-forming complex, one of the most luminous giant H II regions in the Galaxy. We aim to unveil and characterize the young stellar object (YSO) population of the region by analyzing the Ks-band variability and JHKs infrared colors from the VISTA Variables in the Vía Láctea survey. Additionally, SDSS-IV APOGEE-2 infrared spectra of selected objects are analyzed. The sample shows relatively high amplitudes (0.661 mag &lt; ∆KS &lt; 3.521 mag). Most of them resemble sources with outbursts with amplitude &gt;1 mag and duration longer than a few days, typically at least a year, known as eruptive variables. About 60% are likely to be Class II/flat/I objects. This is also confirmed by the spectral index α when available. From the analysis of APOGEE-2 near-infrared spectra of sources in the region, another 122 stars are classified as YSOs and display some infrared variability. The measured effective temperature Teff peak is around 4000 K, and they are slightly supersolar in metal abundance. The modal radial velocity is approximately -41 km s-1. Combining available catalogs of YSOs in the region with our data, we investigate the spatial distributions of 700 YSOs. They are clearly concentrated within the central cavity formed by the massive clusters Danks 1 and 2. The calculated surface density for the entire catalog is 0.025 YSOs pc-2, while the central cavity contains 10 times more objects per area (0.238 YSOs pc-2).

Keywords: Infrared astronomy, Open star clusters, Pre-main sequence stars, Irregular variable stars
Some Aspects of the Tachyon Inflation with Superpotential in Confrontation with Planck2018 Data. We study tachyon inflation in the presence of the superpotential as an inflationary potential. We study the primordial perturbations and their non-Gaussian feature in the equilateral configuration. We use the Planck2018 TT, TE, EE+lowE+lensing+BK14+BAO joint data at 68% CL and 95% CL to perform numerical analysis on the scalar perturbations and seek the observational viability of the tachyon inflation with superpotential. We also check the observational viability of the model by studying the tensor part of the perturbations and comparing the results with Planck2018 TT, TE, EE+lowE+lensing+BK14+BAO+ LIGO&amp;Virgo2016 joint data at 68% CL and 95% CL. By studying the phase space of the model's parameters, we predict the amplitude of the equilateral non-Gaussianity in this model. The reheating phase after inflation is another issue that is explored in this paper. We show that, in some ranges of the model's parameters, it is possible to have an observationally viable tachyon model with superpotential.

Keywords: Observational cosmology, Inflationary universe, Early universe
An 86 GHz Search for Pulsars in the Galactic Center with the Atacama Large Millimeter / submillimeter Array. We report on the first pulsar and transient survey of the Galactic Center (GC) with the Atacama Large Millimeter/submillimeter Array (ALMA). The observations were conducted during the Global Millimeter VLBI Array campaign in 2017 and 2018. We carry out searches using time series of both total intensity and other polarization components in the form of Stokes parameters. We incorporate acceleration and its derivative in the pulsar search, and also search in segments of the entire observation to compensate for potential orbital motion of the pulsar. While no new pulsar is found, our observations yield the polarization profile of the GC magnetar PSR J1745-2900 at millimeter wavelength for the first time, which turns out to be nearly 100% linearly polarized. Additionally, we estimate the survey sensitivity placed by both system and red noise, and evaluate its capability of finding pulsars in orbital motion with either Sgr A* or a binary companion. We show that the survey is sensitive to only the most luminous pulsars in the known population and future observations with ALMA in Band-1 will deliver significantly deeper survey sensitivity on the GC pulsar population.

Keywords: Galactic center, Radio pulsars, Pulsars