Sazuna/UAT_keywords huggingface dataset:
Early Planet Formation in Embedded Disks (eDisk). IV. The Ringed and Warped Structure of the Disk around the Class I Protostar L1489 IRS. Constraining the physical and chemical structure of young embedded disks is crucial for understanding the earliest stages of planet formation. As part of the Early Planet Formation in Embedded Disks Atacama Large Millimeter/submillimeter Array Large Program, we present high spatial resolution (~0.″1 or ~15 au) observations of the 1.3 mm continuum and 13CO J = 2-1, C18O J = 2-1, and SO J  N  = 65-54 molecular lines toward the disk around the Class I protostar L1489 IRS. The continuum emission shows a ring-like structure at 56 au from the central protostar and tenuous, optically thin emission extending beyond ~300 au. The 13CO emission traces the warm disk surface, while the C18O emission originates from near the disk midplane. The coincidence of the radial emission peak of C18O with the dust ring may indicate a gap-ring structure in the gaseous disk as well. The SO emission shows a highly complex distribution, including a compact, prominent component at ≲30 au, which is likely to originate from thermally sublimated SO molecules. The compact SO emission also shows a velocity gradient along a direction tilted slightly (~15°) with respect to the major axis of the dust disk, which we interpret as an inner warped disk in addition to the warp around ~200 au suggested by previous work. These warped structures may be formed by a planet or companion with an inclined orbit, or by a gradual change in the angular momentum axis during gas infall.

Keywords: Planetary system formation, Protostars, Protoplanetary disks
Elemental Abundances in M31: Individual and Coadded Spectroscopic [Fe/H] and [α/Fe] throughout the M31 Halo with SPLASH. We present spectroscopic chemical abundances of red giant branch stars in Andromeda (M31), using medium-resolution (R ~ 6000) spectra obtained via the Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo survey. In addition to individual chemical abundances, we coadd low signal-to-noise ratio spectra of stars to obtain a high enough signal to measure average [Fe/H] and [α/Fe] abundances. We obtain individual and coadded measurements for [Fe/H] and [α/Fe] for M31 halo stars, covering a range of 9-180 kpc in projected radius from the center of M31. With these measurements, we greatly increase the number of outer halo (R proj &gt; 50 kpc) M31 stars with spectroscopic [Fe/H] and [α/Fe], adding abundance measurements for 45 individual stars and 33 coadds from a pool of an additional 174 stars. We measure the spectroscopic metallicity ([Fe/H]) gradient, finding a negative radial gradient of -0.0084 ± 0.0008 for all stars in the halo, consistent with gradient measurements obtained using photometric metallicities. Using the first measurements of [α/Fe] for M31 halo stars covering a large range of projected radii, we find a positive gradient (+0.0027 ± 0.0005) in [α/Fe] as a function of projected radius. We also explore the distribution in [Fe/H]-[α/Fe] space as a function of projected radius for both individual and coadded measurements in the smooth halo, and compare these measurements to those stars potentially associated with substructure. These spectroscopic abundance distributions add to existing evidence that M31 has had an appreciably different formation and merger history compared to our own Galaxy.

Keywords: Local Group, Stellar streams, Stellar abundances, Galaxy stellar halos, Andromeda Galaxy
Constraints on the Gamma-Ray Emission from Small Solar System Bodies with the Fermi Large Area Telescope Data. All known small solar system bodies have diameters between a few meters and a few thousands of kilometers. Based on the collisional evolution of solar system bodies, a larger number of asteroids with diameters down to ~2 m is thought to exist. As all solar system bodies, small bodies can be passive sources of high-energy gamma-rays, produced by the interaction of energetic cosmic rays impinging on their surfaces. Since the majority of known asteroids are in orbits between Mars and Jupiter (in a region known as the Main Belt), we expect them to produce a diffuse emission close to the ecliptic plane. In this work, we have studied the gamma-ray emission coming from the ecliptic using the data collected by the Large Area Telescope (LAT) onboard the Fermi satellite. We have fit the results with simulations of the gamma-ray intensity at the source level (calculated with the software FLUKA) to constrain the small solar system bodies population. Finally, we have proposed a model describing the distribution of asteroid sizes and we have used the LAT data to constrain the gamma-ray emission expected from this model and, in turn, on the model itself.

Keywords: Cosmic rays, Asteroids, Gamma-rays
Energy Flux and Particle Flux in Steady-state Solutions of Nuclear Star Clusters. We examine the effects of two-body interactions in a nuclear star cluster surrounding a supermassive black hole. We evaluate the energy flux, analogously to the particle flux calculation of Bahcall and Wolf. We show that there are two types of power-law steady-state solutions: one with zero energy flux and constant particle flux and the other with constant energy flux and zero particle flux. We therefore prove that a zero particle flux solution, which corresponds to the case of an accreting supermassive black hole, can be obtained by requiring a constant energy flux. Consequently, this solution can be derived by simple dimensional analysis, bypassing the need for detailed calculation. Finally, we show that this characteristic, of zero particle flux for constant energy flux and vice versa, is not unique to the Keplerian potential of a supermassive black hole but holds for any central potential of the form ϕ ∝ r -β .

Keywords: Supermassive black holes, Galactic center, Stellar dynamics, Star clusters
Revisiting the Properties of X-Ray Active Galactic Nuclei in the SSA22 Protocluster: Normal Supermassive Black Hole and Host-galaxy Growth for AGNs in a z = 3.09 Overdensity. We analyze the physical properties of eight X-ray-selected active galactic nuclei (AGNs) and one candidate protoquasar system (ADF22A1) in the z = 3.09 SSA22 protocluster by fitting their X-ray-to-IR spectral energy distributions (SEDs) using our SED-fitting code, LIGHTNING (https://www.github.com/rafaeleufrasio/lightning). We recover star formation histories (SFHs) for seven of these systems which are well fit by composite stellar population plus AGN models. We find indications that four out of nine of the SSA22 AGN systems we study have host galaxies below the main sequence, with SFR/SFRMS ≤ -0.4. The remaining SSA22 systems, including ADF22A1, are consistent with obscured supermassive black hole (SMBH) growth in star-forming galaxies. We estimate the SMBH accretion rates and masses, and compare the properties and SFHs of the nine protocluster AGN systems with X-ray-detected AGN candidates in the Chandra Deep Fields (CDF), finding that the distributions of SMBH growth rates, star formation rates (SFRs), SMBH masses, and stellar masses for the protocluster AGNs are consistent with field AGNs. We constrain the ratio between the sample-averaged SSA22 SMBH mass and CDF SMBH mass to &lt;1.41. While the AGNs are located near the density peaks of the protocluster, we find no statistically significant trends between the AGN or host-galaxy properties and their location in the protocluster. We interpret the similarity of the protocluster and field AGN populations together with existing results as suggesting that the protocluster and field AGNs coevolve with their hosts in the same ways, while AGN-triggering events are more likely in the protocluster.

Keywords: AGN host galaxies, Supermassive black holes, Protoclusters, Active galactic nuclei, Galaxy evolution
You Are What You Eat: The Circumgalactic Medium around BreakBRD Galaxies Has Low Mass and Angular Momentum. Observed breakBRD ("break bulges in red disks") galaxies are a nearby sample of face-on disk galaxies with particularly centrally concentrated star formation: they have red disks but recent star formation in their centers as measured by the D n 4000 spectral index. In Kopenhafer et al., a comparable population of breakBRD analogs was identified in the TNG simulation, in which the central concentration of star formation was found to reflect a central concentration of dense, star-forming gas caused by a lack of dense gas in the galaxy outskirts. In this paper, we examine the circumgalactic medium of the central breakBRD analogs to determine if the extended halo gas also shows differences from that around comparison galaxies with comparable stellar mass. We examine the circumgalactic medium gas mass, specific angular momentum, and metallicity in these galaxy populations. We find less gas in the circumgalactic medium of breakBRD galaxies, and that the breakBRD circumgalactic medium is slightly more concentrated than that of comparable M * galaxies. In addition, we find that the angular momentum in the circumgalactic medium of breakBRD galaxies tends to be low for their stellar mass, and shows more misalignment to the angular momentum vector of the stellar disk. Finally, we find that the circumgalactic medium metallicity of breakBRD galaxies tends to be high for their stellar mass. Together with their low star formation rate, we argue that these circumgalactic medium properties indicate a small amount of disk feeding concentrated in the central regions and a lack of low-metallicity gas accretion from the intergalactic medium.

Keywords: Hydrodynamical simulations, Galaxy evolution, Circumgalactic medium
First Evidence of Multi-iron Subpopulations in the Bulge Fossil Fragment Candidate Liller 1. In the context of a project aimed at characterizing the properties of the so-called Bulge Fossil Fragments (the fossil remnants of the bulge formation epoch), here we present the first determination of the metallicity distribution of Liller 1. For a sample of 64 individual member stars we used ESO-MUSE spectra to measure the equivalent width of the Ca II triplet and then derive the iron abundance. To test the validity of the adopted calibration in the metal-rich regime, the procedure was first applied to three reference bulge globular clusters (NGC 6569, NGC 6440, and NGC 6528). In all the three cases, we found single-component iron distributions, with abundance values fully in agreement with those reported in the literature. The application of the same methodology to Liller 1 yielded, instead, a clear bimodal iron distribution, with a subsolar component at [Fe/H] = -0.48 dex (σ = 0.22) and a supersolar component at [Fe/H] = +0.26 dex (σ = 0.17). The latter is found to be significantly more centrally concentrated than the metal-poor population, as expected in a self-enrichment scenario and in agreement with that found in another bulge system, Terzan 5. The obtained metallicity distribution is astonishingly similar to that predicted by the reconstructed star formation history of Liller 1, which is characterized by three main bursts and a low, but constant, activity of star formation over the entire lifetime. These findings provide further support to the possibility that, similar to Terzan 5, Liller 1 is also a Bulge Fossil Fragment. * Based on observations collected at the Very Large Telescope of the European Southern Observatory, Cerro Paranal (Chile), under the ESO-VLT Multi-Instrument Kinematic Survey (MIKiS survey) programs 106.21N5 and 105.20B9 (PI: Ferraro) and under MUSE science verification programs: 60.A-9489;60.A-9343.

Keywords: Globular star clusters, Galactic bulge, Spectroscopy, Star clusters
X-Ray and Ultraviolet Emission of the Young Planet-hosting Star V1298 Tau from Coordinated Observations with XMM-Newton and Hubble Space Telescope. Atmospheric mass loss plays a major role in the evolution of exoplanets. This process is driven by the stellar high-energy irradiation, especially in the first hundreds of millions of years after dissipation of the proto-planetary disk. A major source of uncertainty in modeling atmospheric photoevaporation and photochemistry is due to the lack of direct measurements of the stellar flux at extreme-UV (EUV) wavelengths. Several empirical relationships have been proposed in the past to link EUV fluxes to emission levels in X-rays, but the stellar samples employed for this aim are heterogeneous, and the available scaling laws provide significantly different predictions, especially for very active stars. We present new far-UV and X-ray observations of V1298 Tau with Hubble Space Telescope/Cosmic Origins Spectrograph and XMM-Newton, aimed to determine more accurately the high-energy emission of this solar-mass pre-main-sequence star, which hosts four exoplanets. Spectroscopic data were employed to derive the plasma emission measure distribution versus temperature, from the chromosphere to the corona, and the possible variability of this irradiation on short and year-long timescales, due to magnetic activity. As a side result, we have also measured the chemical abundances of several elements in the outer atmosphere of V1298 Tau. We employ our results as a new benchmark point for the calibration of the X-ray to EUV scaling laws, and hence to predict the time evolution of the irradiation in the EUV band, and its effect on the evaporation of exo-atmospheres.

Keywords: Ultraviolet spectroscopy, Extreme ultraviolet astronomy, Stellar activity, Pre-main sequence stars, Star-planet interactions, Single x-ray stars
Investigating the Impact of Vertically Extended Coronae on X-Ray Reverberation Mapping. Accreting black holes commonly exhibit hard X-ray emission, originating from a region of hot plasma near the central engine referred to as the corona. The origin and geometry of the corona are poorly understood, and models invoking either inflowing or outflowing material (or both) can successfully explain only parts of the observed phenomenology. In particular, recent works indicate that the time-averaged and variability property might originate in different regions of the corona. In this paper we present a model designed to move beyond the lamppost paradigm, with the goal of accounting for the vertical extent of the corona. In particular, we highlight the impact of including self-consistently a second lamppost, mimicking, for example, an extended jet base. We fully include the effect that the second source has on the time-dependent disk ionization, reflection spectrum, and reverberation lags. We also present an application of this new model to NICER observations of the X-ray binary MAXI J1820+070 near its hard-to-soft state transition. We demonstrate that in these observations, a vertically extended corona can capture both spectral and timing properties, while a single-lamppost model can not. In this scenario, the illumination responsible for the time-averaged spectrum originates close to the black hole, while the variability is likely associated with the ballistic jet.

Keywords: Accretion, Black hole physics, Reverberation mapping
Constraints on Undetected Long-period Binaries in the Known Pulsar Population. Although neutron star-black hole binaries have been identified through mergers detected in gravitational waves, a pulsar-black hole binary has yet to be detected. While short-period binaries are detectable due to a clear signal in the pulsar's timing residuals, effects from a long-period binary could be masked by other timing effects, allowing them to go undetected. In particular, a long-period binary measured over a small subset of its orbital period could manifest via time derivatives of the spin frequency incompatible with isolated pulsar properties. We assess the possibility of pulsars having unknown companions in long-period binaries and put constraints on the range of binary properties that may remain undetected in current data, but that may be detectable with further observations. We find that for 35% of canonical pulsars with published higher-order derivatives, the precision of measurements is not enough to confidently reject binarity (period ≳2 kyr), and that a black hole binary companion could not be ruled out for a sample of pulsars without published constraints if the period is &gt;1 kyr. While we find no convincing cases in the literature, we put more stringent limits on orbital period and longitude of periastron for the few pulsars with published higher-order frequency derivatives (n ≥ 3). We discuss the detectability of candidates and find that a sample pulsar in a 100 yr orbit could be detectable within 5-10 yr.

Keywords: Binary pulsars, Black holes
Temperature of the Polar Inner Heliosheath: Connection to Solar Activity. We study the thermodynamics of the plasma protons in the polar regions of the inner heliosheath (IHS) and its connection with solar activity over solar cycle 24. First, we express the thermodynamic parameters of this plasma with respect to the year of energetic neutral atom (ENA) creation and perform a statistical analysis of temperatures, in order to provide a more precise characterization of the thermodynamics of IHS. Then, we perform an autocorrelation between the IHS temperature and the solar activity, using the proxies of sunspot number and fractional area of the polar coronal holes. We show that there is (i) high correlation between the time series of IHS proton temperatures and sunspot number, which is maximized for a time delay of τ ~ 2.5 yr for both the north and south polar regions combined; (ii) high negative correlation between the temperature of the proton plasma in the north and south with the coronal hole fractional areas, where the time delay for the two poles combined is τ ~ 2.71 ± 0.15 yr; and (iii) an asymmetry of a time-delay difference between the poles ~0.22 yr, indicating that the southern polar ENA source region is ~19 au closer than the northern one for a solar wind plasma protons of bulk speed of ~400 km s-1. The findings demonstrate a connection between the IHS thermodynamics and solar activity through the solar wind, primarily manifested by the coronal holes expanding near solar minimum, which drives the expansion of fast solar wind over larger angles from high down to middle latitudes in the IHS.

Keywords: Solar cycle, Space plasmas, Heliosheath, Heliosphere
A Spectroscopic Model of the Type Ia Supernova-Host-galaxy Mass Correlation from SALT3. The unknown cause of the correlation between Type Ia supernova (SN Ia) Hubble residuals and their host-galaxy masses (the "mass step") may bias cosmological parameter measurements. To better understand the mass step, we develop a SALT3 light-curve model for SN cosmology that uses the host-galaxy masses of 296 low-redshift SNe Ia to derive a spectral energy distribution-host-galaxy mass relationship. The resulting model has larger Ca II H and K, Ca II near-infrared triplet, and Si II equivalent widths for SNe in low-mass host galaxies at 2.2-2.7σ significance; this indicates higher explosion energies per unit mass in low-mass-hosted SNe. The model has phase-dependent changes in SN Ia colors as a function of host mass, indicating intrinsic differences in mean broadband light curves. Although the model provides a better fit to the SN data overall, it does not substantially reduce data-model residuals for a typical light curve in our sample nor does it significantly reduce Hubble residual dispersion. This is because we find that previous SALT models parameterized most host-galaxy dependencies with their first principal component, although they failed to model some significant spectral variations. Our new model is luminosity and cosmology independent, and applying it to data reduces the mass step by 0.021 ± 0.002 mag (uncertainty accounts for correlated data sets); these results indicate that ~35% of the mass step can be attributed to luminosity-independent effects. This SALT model version could be trained using alternative host-galaxy properties and at different redshifts, and therefore will be a tool for understanding redshift-dependent correlations between SNe Ia and their host properties as well as their impact on cosmological parameter measurements.

Keywords: Cosmology, Distance measure, Type Ia supernovae, Dark energy
Limitations and Biases in the Retrieval of the Polar Magnetic Field. I. The Role of the Magnetic Filling Factor in Milne-Eddington Inversions of Simulated Hinode/SP Data. We study the extent to which Milne-Eddington inversions are able to retrieve and characterize the magnetic landscape of the solar poles from observations by the spectropolarimeter on board Hinode. In particular, we evaluate whether a variable magnetic filling factor is an adequate modeling technique for retrieving the intrinsic magnetic properties from every pixel in the polar field of view. We first generate synthetic spectra emerging from a numerical simulation of a "plage" region at an inclined line of sight of 65°, and degrade the data to emulate real observations. Then, we invert the synthetic spectra with two Milne-Eddington inversion codes that feature different treatments of the magnetic filling factor, and relate the retrieved magnetic quantities back to their original values in the simulation cube. We find that, while the apparent retrieved magnetic properties map the spatially degraded simulation well, the intrinsic magnetic quantities bear little relation to the magnetic field at the native resolution of the simulation. We discuss the systematic biases caused by line-of-sight foreshortening, spatial degradation, photon noise, and modeling assumptions embedded in the inversion algorithm.

Keywords: Solar photosphere, Spectropolarimetry, Solar magnetic fields
Mechanochemical Synthesis of Amorphous Silicates with an Enstatite and Forsterite Composition. The presence of amorphous silicate particles in interstellar and circumstellar space has been suggested based on the observation of 9.7 and 18 μm emission bands. We have successfully synthesized amorphous silicate samples of an enstatite and forsterite composition by the mechanical milling of mixed powder consisting of SiO2-MgO and SiO2-Mg(OH)2 reagent-grade particles under different rotation frequencies and milling times. These two types of starting materials are prepared to study the effect of the OH bond on synthesis and crystallization. The amorphous samples were characterized by X-ray diffraction and infrared spectroscopy. Amorphous samples with enstatite composition are synthesized from both SiO2-MgO and SiO2-Mg(OH)2 at 300 rpm and for 300 hr. Amorphous samples with forsterite composition are synthesized from both SiO2-MgO and SiO2-Mg(OH)2. The samples from SiO2-Mg(OH)2 require 400 rpm and a long milling time of 1600 hr. After crystallization, amorphous samples with an enstatite composition synthesized from SiO2-Mg(OH)2 mainly transform into forsterite with small amounts of amorphous silica SiO2 and enstatite depending on the rotation frequencies and milling time, while those from SiO2-MgO become enstatite. The amorphous samples with a forsterite composition are crystallized to forsterite from both starting materials. The presence of H2O or OH bonds significantly affects the final products after the crystallization of amorphous silicates of enstatite composition.

Keywords: Dust continuum emission, Infrared spectroscopy, Infrared observatories