Sazuna/UAT_keywords huggingface dataset:
Constraints on Cosmological Parameters from the 500 deg<SUP>2</SUP> SPTPOL Lensing Power Spectrum. We present cosmological constraints based on the cosmic microwave background (CMB) lensing potential power spectrum measurement from the recent 500 deg2 SPTpol survey, the most precise CMB lensing measurement from the ground to date. We fit a flat ΛCDM model to the reconstructed lensing power spectrum alone and in addition with other data sets: baryon acoustic oscillations (BAO), as well as primary CMB spectra from Planck and SPTpol. The cosmological constraints based on SPTpol and Planck lensing band powers are in good agreement when analyzed alone and in combination with Planck full-sky primary CMB data. With weak priors on the baryon density and other parameters, the SPTpol CMB lensing data alone provide a 4% constraint on ${\sigma }_{8}{{\rm{\Omega }}}_{m}^{0.25}=0.593\pm 0.025$ . Jointly fitting with BAO data, we find ${\sigma }_{8}=0.779\pm 0.023$ , ${{\rm{\Omega }}}_{m}={0.368}_{-0.037}^{+0.032}$ , and ${H}_{0}={72.0}_{-2.5}^{+2.1}\,\mathrm{km}\,{{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$ , up to $2\sigma $ away from the central values preferred by Planck lensing + BAO. However, we recover good agreement between SPTpol and Planck when restricting the analysis to similar scales. We also consider single-parameter extensions to the flat ΛCDM model. The SPTpol lensing spectrum constrains the spatial curvature to be ${{\rm{\Omega }}}_{K}=-0.0007\pm 0.0025$ and the sum of the neutrino masses to be $\sum {m}_{\nu }\lt 0.23$ eV at 95% C.L. (with Planck primary CMB and BAO data), in good agreement with the Planck lensing results. With the differences in the signal-to-noise ratio of the lensing modes and the angular scales covered in the lensing spectra, this analysis represents an important independent check on the full-sky Planck lensing measurement.

Keywords: Weak gravitational lensing, Cosmic microwave background radiation, Cosmological parameters
Distortion of Magnetic Fields in a Starless Core. VI. Application of Flux Freezing Model and Core Formation of FeSt 1-457. Observational data for the hourglass-like magnetic field toward the starless dense core FeSt 1-457 were compared with a flux freezing magnetic field model. Fitting of the observed plane-of-sky magnetic field using the flux freezing model gave a residual angle dispersion comparable to the results based on a simple 3D parabolic model. The best-fit parameters for the flux freezing model were a line-of-sight magnetic inclination angle of γmag = 35° ± 15° and a core center to ambient (background) density contrast of ρc/ρbkg = 75. The initial density for core formation (ρ0) was estimated to be ρc/75 = 4670 cm-3, which is about one order of magnitude higher than the expected density (∼300 cm-3) for the interclump medium of the Pipe Nebula. FeSt 1-457 is likely to have been formed from the accumulation of relatively dense gas, and the relatively dense background column density of AV ≃ 5 mag supports this scenario. The initial radius (core formation radius) R0 and the initial magnetic field strength B0 were obtained to be 0.15 pc (1.64R) and 10.8-14.6 μG, respectively. We found that the initial density ρ0 is consistent with the mean density of the nearly critical magnetized filament with magnetic field strength B0 and radius R0. The relatively dense initial condition for core formation can be naturally understood if the origin of the core is the fragmentation of magnetized filaments.

Keywords: Interstellar dust, Dense interstellar clouds, Infrared astronomy, Starlight polarization, Magnetic fields
An Observationally Constrained Analytical Model for Predicting the Magnetic Field Vectors of Interplanetary Coronal Mass Ejections at 1 au. We report on an observationally constrained analytical model, the INterplanetary Flux ROpe Simulator (INFROS), for predicting the magnetic field vectors of coronal mass ejections (CMEs) in the interplanetary medium. The main architecture of INFROS involves using the near-Sun flux rope properties obtained from the observational parameters that are evolved through the model in order to estimate the magnetic field vectors of interplanetary CMEs (ICMEs) at any heliocentric distance. We have formulated a new approach in INFROS to incorporate the expanding nature and the time-varying axial magnetic field strength of the flux rope during its passage over the spacecraft. As a proof of concept, we present the case study of an Earth-impacting CME which occurred on 2013 April 11. Using the near-Sun properties of the CME flux rope, we have estimated the magnetic vectors of the ICME as intersected by the spacecraft at 1 au. The predicted magnetic field profiles of the ICME show good agreement with those observed by the in situ spacecraft. Importantly, the maximum strength (10.5 ± 2.5 nT) of the southward component of the magnetic field (Bz) obtained from the model prediction is in agreement with the observed value (11 nT). Although our model does not include the prediction of the ICME plasma parameters, as a first-order approximation, it shows promising results in forecasting of Bz in near real time, which is critical for predicting the severity of the associated geomagnetic storms. This could prove to be a simple space-weather forecasting tool compared to the time-consuming and computationally expensive MHD models.

Keywords: Space weather, Solar flares, Solar coronal mass ejections
O<SUB>2</SUB>- and CO-rich Atmospheres for Potentially Habitable Environments on TRAPPIST-1 Planets. Small exoplanets of nearby M-dwarf stars present the possibility of finding and characterizing habitable worlds within the next decade. TRAPPIST-1, an ultracool M-dwarf star, was recently found to have seven Earth-sized planets of predominantly rocky composition. The planets e, f, and g could have a liquid water ocean on their surface given appropriate atmospheres of N2 and CO2. In particular, climate models have shown that the planets e and f can sustain a global liquid water ocean, for ≥0.2 bar CO2 plus 1 bar N2, or ≥2 bar CO2, respectively. These atmospheres are irradiated by ultraviolet emission from the star's moderately active chromosphere, and the consequence of this irradiation is unknown. Here we show that chemical reactions driven by the irradiation produce and maintain more than 0.2 bar O2 and 0.05 bar CO if the CO2 is ≥0.1 bar. The abundance of O2 and CO can rise to more than 1 bar under certain boundary conditions. Because of this O2-CO runaway, habitable environments on the TRAPPIST-1 planets entail an O2- and CO-rich atmosphere with coexisting O3. The only process that would prevent runaway is direct recombination of O2 and CO in the ocean, a reaction that is facilitated biologically. Our results indicate that O2, O3, and CO should be considered together with CO2 as the primary molecules in the search for atmospheric signatures from temperate and rocky planets of TRAPPIST-1 and other M-dwarf stars.

Keywords: Extrasolar rocky planets, Super Earths, Astrobiology, Habitable zone, Habitable planets, Exoplanet atmospheres
Precision of Mass and Radius Determination for Neutron Stars from the ATHENA Mission. In this paper we show that X-ray spectral observations of the ATHENA mission, which is planned to launch in 2031, can constrain the equation of state (EOS) of superdense matter. We use our well-constrained continuum-fitting method to determine the mass and radius of a neutron star. Model spectra of the emission from a neutron star were calculated using the atmosphere code ATM24. In the next step, those models were fitted to simulated spectra of the neutron star calculated for ATHENA's Wide Field Imager (WFI) detector, using satellite calibration files. To simulate the spectra we assumed three different values of effective temperature, surface gravity, and gravitational redshift. These cases relate to three different neutron star masses and radii. This analysis allows us to demonstrate both the precision of our method and the need for a fast detector onboard ATHENA. A large grid of theoretical spectra was calculated with various parameters and a hydrogen-helium-iron composition of solar proportions. These spectra were fitted to the simulated spectrum to estimate the precision of mass and radius determination. In each case, we obtained very precise values with errors in the range 3%-10% for mass and 2%-8% for radius within 1σ confidence. We show here that, with the ATHENA WFI detector, such a determination could be used to constrain the EOS of superdense neutron star matter.

Keywords: Neutron stars, Stellar atmospheres, Compact objects
Stellar Properties of z ≳ 8 Galaxies in the Reionization Lensing Cluster Survey. Measurements of stellar properties of galaxies when the universe was less than one billion years old yield some of the only observational constraints on the onset of star formation. We present here the inclusion of Spitzer/IRAC imaging in the fitting of the spectral energy distribution of the seven highest-redshift galaxy candidates selected from the Hubble Space Telescope (HST) imaging of the Reionization Lensing Cluster Survey. We find that for six out of eight HST-selected z ∼ 8 sources, the z ∼ 8 solutions are still strongly preferred over z ∼ 1-2 solutions after the inclusion of Spitzer fluxes, and two prefer a z ∼ 7 solution, which we defer to a later analysis. We find a wide range of intrinsic stellar masses (5 × 106-4 × 109 M☉), star formation rates (0.2-14 M☉ yr-1), and ages (30-600 Myr) among our sample. Of particular interest is A1763-1434, which shows evidence of an evolved stellar population (∼500 Myr) at z ∼ 8, implying that its first generation of star formation occurred &lt;100 Myr after the Big Bang. SPT0615-JD, a spatially resolved z ∼ 10 candidate, remains at its high redshift, supported by deep Spitzer/IRAC data, and also shows some evidence for an evolved stellar population. Even with the lensed, bright apparent magnitudes of these z ≳ 8 candidates (H = 26.1-27.8 AB mag), only the James Webb Space Telescope will be able to exclude the possibility of abnormally strong nebular emission, large dust content, or some combination thereof, and confirm the presence of evolved stellar populations early in the universe.

Keywords: Broad band photometry, High-redshift galaxies
Modeling the Precession of the Warped Inner Accretion Disk in the Pulsars LMC X-4 and SMC X-1 with NuSTAR and XMM-Newton. We present a broadband X-ray study of the effect of superorbital periods on X-ray spectra and pulse profiles in the neutron star X-ray binaries LMC X-4 and SMC X-1. These two sources display periodic or quasiperiodic variations in luminosity of the order of tens of days, which are known to be superorbital, and are attributed to warped, precessing accretion disks. Using joint NuSTAR and XMM-Newton observations that span a complete superorbital cycle, we examine the broadband spectra of these sources and find the shape to be well described by an absorbed power law with a soft blackbody component. Changes in spectral shape and pulse profile shape are periodic with superorbital period, as expected from a precessing disk. We perform X-ray tomography using the changes in pulse profiles to model the geometry and kinematics of the inner accretion disk. Our simple geometric model of a beam and inner disk indicates that the long-term changes in soft pulse shape and phase are consistent with reprocessed emission from a precessing inner disk.

Keywords: Neutron stars, Compact objects, Pulsars
Chromium Isotopic Constraints on the Origin of the Ureilite Parent Body. We report on the mass-independent Cr isotope compositions of 11 main group ureilites and an ureilitic trachyandesite (ALM-A). The 54Cr/52Cr ratios for main group ureilites vary from -1.06 ± 0.04 to -0.78 ± 0.05 and averaged at -0.91 ± 0.15 (2SD, N = 18) including the data from literature. We argue that this variation reflects primitive mantle heterogeneities within the ureilite parent body (UPB). As such, this body did not experience a global-scale magma ocean, which is consistent with heterogeneous O isotope in ureilites. Furthermore, the ɛ54Cr values, Mn/Cr ratios, C isotope ratios, Mg# values, and Fe/Mn ratios in the olivine cores of ureilites are correlated with each other, which suggests the mixing of ureilite precursors from at least two reservoirs, rather than a smelting process or the oxidation from ice melting. All the ureilite samples (including the ALM-A) fall on a well-defined 53Mn-53Cr isochron corresponding to a 53Mn/55Mn ratio of (6.02 ± 1.59) × 10-6, which translates to an age of 4566.7 ± 1.5 Ma (within 2 Ma after calcium-aluminum-rich inclusions; CAIs) when anchored to the U-corrected Pb-Pb age for the D'Orbigny angrite. This old age indicates early partial melting on the UPB, consistent with the early accretion of the UPB (within 1 Ma after CAIs) predicted by thermal modeling. Furthermore, there is a 4∼5 Ma age difference between the external isochron in this study and internal isochron ages for the feldspathic clasts in polymict ureilites, which likely reflects an impact history during the early evolution of the UPB.

Keywords: Isotopic abundances, Cosmochemistry, Small Solar System bodies, Asteroids, Solar system planets, Nucleosynthesis, Astrochemistry, Cosmochronology
Hypothetical Hyperbolic Encounters between Venus and Proto-Mercury that Partially Stripped Away Proto-Mercury’s Mantle. Compared to all other terrestrial planets in the solar system, Mercury has an unusually large metal core, comprising ∼70% of its mass. Giant impacts could have removed a significant fraction of the silicate mantle of a chondritic proto-Mercury, forming the iron-rich present-day Mercury. However, such high-temperature giant impacts seem at odds with the retention of moderately volatile elements on present-day Mercury. We simulated a series of hyperbolic encounters between proto-Mercury and proto-Venus, which may have occurred in the chaotic early solar system. Tidal disruption of proto-Mercury always removes a portion of its silicate mantle, while its iron core remains intact. We find, in favorable cases, four close encounters with fast-spinning projectiles (resulting from previous encounters) that could lead to Mercury’s present-day iron fraction. More encounters are needed when the spin and orbital angular momentum are not always aligned. These hyperbolic encounters have various outcomes, such as orbital decay, binary planets, and change of spin rates. These results suggest the importance of the proper treatment of close encounters in N-body simulations of planetary accretion.

Keywords: Impact phenomena, Tidal disruption, Computational astronomy, Solar system formation
Stellar Winds Pump the Heart of the Milky Way. The central supermassive black hole of the Milky Way, Sgr A*, accretes at a very low rate making it a very underluminous galactic nucleus. Despite the tens of Wolf-Rayet stars present within the inner parsec supplying ∼10-3 M ⊙ yr-1 in stellar winds, only a negligible fraction of this material (&lt;10-4) ends up being accreted onto Sgr A*. The recent discovery of cold gas (∼104 K) in its vicinity raised questions about how such material could settle in the hostile (∼107 K) environment near Sgr A*. In this work we show that the system of mass-losing stars blowing winds can naturally account for both the hot, inefficient accretion flow, as well as the formation of a cold disk-like structure. We run hydrodynamical simulations using the grid-based code RAMSES starting as early in the past as possible to observe the state of the system at the present time. Our results show that the system reaches a quasi-steady state in about ∼500 yr with material being captured at a rate of ∼10-6 M ⊙ yr-1 at scales of ∼10-4 pc, consistent with the observations and previous models. However, on longer timescales (≳3000 yr) the material accumulates close to the black hole in the form of a disk. Considering the duration of the Wolf-Rayet phase (∼105 yr), we conclude that this scenario has likely already happened, and could be responsible for the more active past of Sgr A*, and/or its current outflow. We argue that the hypothesis of the mass-losing stars being the main regulator of the activity of the black hole deserves further consideration.

Keywords: Accretion, Stellar winds, Galactic center, Hydrodynamics
Formation and Merging of Mass Gap Black Holes in Gravitational-wave Merger Events from Wide Hierarchical Quadruple Systems. We investigate secular evolution in hierarchical quadruple systems as a formation channel of mass-gap black holes (with masses of about 3-5M ⊙) in systems that will eventually lead to binary black hole mergers detectable by ground-based gravitational-wave detectors (LIGO/Virgo). We show that in a 3 + 1 hierarchical system, two episodes of induced mergers would first cause two neutron stars to merge and form a mass-gap black hole, which will subsequently merge with another (more massive) black hole through a second induced merger. We demonstrate that such systems are stable to flybys, and their formation would predict a high mass ratio and eccentric merger of a mass-gap black hole with a more massive black hole companion. Such a formation channel may explain observed gravitational-wave events such as the recently discovered LIGO/Virgo events S190814bv and S190924h.

Keywords: Neutron stars, Gravitational wave sources, Compact objects, Wide binary stars, LIGO, Astrophysical black holes, Dynamical evolution
Long-lived Dust Rings around HD 169142. Recent Atacama Large Millimeter/submillimeter Array (ALMA) observations of the protoplanetary disk around HD 169142 reveal a peculiar structure made of concentric dusty rings: a main ring at ∼20 au, a triple system of rings at ∼55-75 au in millimetric continuum emission, and a perturbed gas surface density from the 12CO,13CO, and C18O (J = 2-1) surface brightness profile. In this Letter, we perform 3D numerical simulations and radiative transfer modeling exploring the possibility that two giant planets interacting with the disk and orbiting in resonant locking can be responsible for the origin of the observed dust inner rings structure. We find that in this configuration the dust structure is actually long lived while the gas mass of the disk is accreted onto the star and the giant planets, emptying the inner region. In addition, we also find that the innermost planet is located at the inner edge of the dust ring, and can accrete mass from the disk, generating a signature in the dust ring shape that can be observed in mm ALMA observations.

Keywords: Planetary system formation, Astrophysical fluid dynamics, Protoplanetary disks
The Orbit of WASP-12b Is Decaying. WASP-12b is a transiting hot Jupiter on a 1.09 day orbit around a late-F star. Since the planet’s discovery in 2008, the time interval between transits has been decreasing by 29 ± 2 ms yr-1. This is a possible sign of orbital decay, although the previously available data left open the possibility that the planet’s orbit is slightly eccentric and is undergoing apsidal precession. Here, we present new transit and occultation observations that provide more decisive evidence for orbital decay, which is favored over apsidal precession by a {{∆ }}{BIC} of 22.3 or Bayes factor of 70,000. We also present new radial-velocity data that rule out the Rømer effect as the cause of the period change. This makes WASP-12 the first planetary system for which we can be confident that the orbit is decaying. The decay timescale for the orbit is P/\dot{P}=3.25+/- 0.23 {Myr}. Interpreting the decay as the result of tidal dissipation, the modified stellar tidal quality factor is {Q}\star {\prime }=1.8× {10}5.

Keywords: Exoplanets, Transit photometry, Hot Jupiters
Five Stellar Populations in M22 (NGC 6656). We present the Ca-CN-CH photometry of the metal-complex globular cluster (GC) M22 (NGC 6656). Our photometry clearly shows the discrete double CN-CH anticorrelations in M22 red giant branch (RGB) stars, due to the difference in the mean metallicity. The populational number ratio between the two main groups is n(G1):n(G2) = 63:37(±3), with the G1 being more metal-poor. Furthermore, the G1 can be divided into two subpopulations with the number ratio of n(CN-w):n(CN-s) = 51:49 (±4), while the G2 can be divided into three subpopulations with n(CN-w):n(CN-I):n(CN-s) = 24:32:44 (±5). The proper motion of individual stars in the cluster shows evidence of internal rotation, showing the G2 with a faster rotation, confirming our previous results from radial velocities. The cumulative radial distributions (CRDs) of individual subpopulations are intriguing in the following aspects: (1) In both main groups, the CRDs of the CN-s subpopulations are more centrally concentrated than other subpopulations. (2) The CRDs of the the G1 CN-s and the G2 CN-s are very similar. (3) Likewise, the G1 CN-w and the G2 CN-w and CN-I have almost identical CRDs. We also estimate the relative helium abundance of individual subpopulations by comparing their RGB bump magnitudes, finding that no helium abundance variation can be seen in the G1, while significant helium enhancements by {{Δ }}Y ≈ 0.03-0.07 are required in the G2. Our results support the idea that M22 formed via a merger of two GCs.

Keywords: Globular star clusters, Hertzsprung Russell diagram, Stellar abundances, Stellar evolution
Modeling Imbalanced Collisionless Alfvén Wave Turbulence with Nonlinear Diffusion Equations. A pair of nonlinear diffusion equations in Fourier space is used to study the dynamics of strong Alfvén wave turbulence, from MHD to electron scales. Special attention is paid to the regime of imbalance between the energies of counter-propagating waves commonly observed in the solar wind (SW), especially in regions relatively close to the Sun. In the collisionless regime where dispersive effects arise at scales comparable to or larger than those where dissipation becomes effective, the imbalance produced by a given injection rate of generalized cross-helicity (GCH), which is an invariant, is much larger than in the corresponding collisional regime described by the usual (or reduced) magnetohydrodynamics. The combined effect of high imbalance and ion Landau damping induces a steep energy spectrum for the transverse magnetic field at sub-ion scales. This spectrum is consistent with observations in highly Alfvénic regions of the SW, such as trailing edges, but does not take the form of a transition range continued at smaller scales by a shallower spectrum. This suggests that the observed spectra displaying such a transition result from the superposition of contributions originating from various streams with different degrees of imbalance. Furthermore, when imbalanced energy injection is supplemented at small scales in an already fully developed turbulence, for example under the effect of magnetic reconnection, a significant enhancement of the imbalance at all scales is observed.

Keywords: Space plasmas, Magnetohydrodynamics, Theoretical models, Plasma physics, Fast solar wind, Solar wind, Magnetohydrodynamical simulations