Sazuna/UAT_keywords huggingface dataset:
Prospects for Detecting Gravitational Waves from Eccentric Subsolar Mass Compact Binaries. Due to their small mass, subsolar mass black hole binaries would have to be primordial in origin instead of the result of stellar evolution. Soon after formation in the early universe, primordial black holes can form binaries after decoupling from the cosmic expansion. Alternatively, primordial black holes as dark matter could also form binaries in the late universe due to dynamical encounters and gravitational-wave braking. A significant feature for this channel is the possibility that some sources retain nonzero eccentricity in the LIGO/Virgo band. Assuming all dark matter is primordial black holes with a delta function mass distribution, 1M⊙-1M⊙ binaries formed in this late-universe channel can be detected by Advanced LIGO and Virgo with their design sensitivities at a rate of ${ \mathcal O }(1)$ yr-1, where 12%(3%) of events have eccentricity at a gravitational-wave frequency of 10 Hz, e10 Hz ≥ 0.01(0.1), and nondetection can constrain the binary formation rate within this model. Third generation detectors would be expected to detect subsolar mass eccentric binaries as light as 0.01M⊙ within this channel, if they accounted for the majority of the dark matter. Furthermore, we use simulated gravitational-wave data to study the ability to search for eccentric gravitational-wave signals using a quasi-circular waveform template bank with Advanced LIGO design sensitivity. For a match-filtering targeted search, assuming binaries with a delta function mass of 0.1(1)M⊙ and the eccentricity distribution derived from this late-universe formation channel, 41%(6%) of the signals would be missed compared to the ideal detection rate due to the mismatch in the gravitational-wave signal from eccentricity.

Keywords: Eccentricity, Gravitational waves, Primordial black holes
Multiwavelength and Neutrino Emission from Blazar PKS 1502 + 106. In 2019 July, the IceCube experiment detected a high-energy neutrino from the direction of the powerful blazar PKS 1502+106. We perform multiwavelength and multimessenger modeling of this source, using a fully selfconsistent one-zone model that includes the contribution of external radiation fields typical of flat-spectrum radio quasars. We identify three different activity states of the blazar: one quiescent state and two flaring states with hard and soft gamma-ray spectra. We find two hadronic models that can describe the multiwavelength emission during all three states: a leptohadronic model with a contribution from photohadronic processes to X-rays and gamma-rays, and a proton synchrotron model, where the emission from keV to 10 GeV comes from proton synchrotron radiation. Both models predict a substantial neutrino flux that is correlated with the gamma-ray and soft X-ray fluxes. Our results are compatible with the detection of a neutrino during the quiescent state, based on event rate statistics. We conclude that the soft X-ray spectra observed during bright flares strongly suggest a hadronic contribution, which can be interpreted as additional evidence for cosmic-ray acceleration in the source independently of neutrino observations. We find that more arguments can be made in favor of the leptohadronic model vis-a-vis the proton synchrotron scenario, such as a lower energetic demand during the quiescent state. However, the same leptohadronic model would be disfavored for flaring states of PKS 1502+106 if no IceCube events were found from the direction of the source before 2010, which would require an archival search.

Keywords: Astronomy data modeling, High-luminosity active galactic nuclei, Astronomical simulations, Gamma-ray sources, Blazars, Cosmological neutrinos, Ultra-high-energy cosmic radiation
ENISALA. II. Distinct Star Formation and Active Galactic Nucleus Activity in Merging and Relaxed Galaxy Clusters. The growth of galaxy clusters is energetic and may trigger and/or quench star formation and black hole activity. The ENISALA4 project is a collection of multiwavelength observations aimed at understanding how large-scale structure drives galaxy and black hole evolution. Here, we introduce optical spectroscopy of over 800 Hα emission-line galaxies, selected in 14 z ∼ 0.15-0.31 galaxy clusters, spanning a range of masses and dynamical states. We investigate the nature of the emission lines in relation to the host galaxy properties, its location within the cluster, and the properties of the parent cluster. We uncover remarkable differences between mergers and relaxed clusters. The majority of Hα emission-line galaxies in merging cluster fields are located within 3 Mpc of their center. A large fraction of these line emitters in merging clusters are powered by star formation irrespective of cluster-centric radius, while the rest are powered by active galactic nuclei (AGNs). Star-forming galaxies are rare within 3 Mpc of relaxed clusters and AGNs are most abundant at their outskirts (∼1.5-3 Mpc). We discover a population of star-forming galaxies with large equivalent widths and blue UV-optical colors found exclusively in the merging clusters in our sample. The widespread emission-line activity in merging clusters is likely supported by triggered activity in recently accreted, gas-rich galaxies. By contrast, our observations for relaxed clusters match established models in which black hole activity is enhanced at the virial radius and star formation is quenched within the infall region. We conclude that emission-line galaxies experience distinct evolutionary paths in merging and relaxed clusters.

Keywords: Galaxy clusters, Spiral galaxies, Galaxy environments, Active galaxies, Emission line galaxies, Star formation, Galaxy evolution, Ionization, Spectroscopy, Shocks, Intracluster medium, Early-type galaxies
Observational Signature of Tightly Wound Spirals Driven by Buoyancy Resonances in Protoplanetary Disks. Besides the spirals induced by the Lindblad resonances, planets can generate a family of tightly wound spirals through buoyancy resonances. The excitation of buoyancy resonances depends on the thermal relaxation timescale of the gas. By computing timescales of various processes associated with thermal relaxation, namely, radiation, diffusion, and gas-dust collision, we show that the thermal relaxation in protoplanetary disks' surface layers (Z/R ≳ 0.1) and outer disks (R ≳ 100 au) is limited by infrequent gas-dust collisions. The use of the isothermal equation of state or rapid cooling, common in protoplanetary disk simulations, is therefore not justified. Using three-dimensional hydrodynamic simulations, we show that the collision-limited slow thermal relaxation provides favorable conditions for buoyancy resonances to develop. Buoyancy resonances produce predominantly vertical motions, whose magnitude at the 12CO emission surface is of the order of 100 m s-1 for Jovian-mass planets, sufficiently large to detect using molecular line observations with ALMA. We generate synthetic observations and describe characteristic features of buoyancy resonances in Keplerian-subtracted moment maps and velocity channel maps. Based on the morphology and magnitude of the perturbation, we propose that the tightly wound spirals observed in TW Hya could be driven by a (sub-)Jovian-mass planet at 90 au. We discuss how non-Keplerian motions driven by buoyancy resonances can be distinguished from those driven by other origins. We argue that observations of multiple lines tracing different heights, with sufficiently high spatial/spectral resolution and sensitivity to separate the emission arising from the near and far sides of the disk, will help constrain the origin of non-Keplerian motions.

Keywords: Submillimeter astronomy, Spiral arms, Protoplanetary disks, Hydrodynamical simulations
Dynamical Tidal Locking Theory: A New Source of the Spin of Dark Matter Halos. We revisit the question of what mechanism is responsible for the spins of halos of dark matter. The answer to this question is of high importance for modeling galaxy intrinsic alignment, which can potentially contaminate current and future lensing data. In particular, we show that when the dark matter halos pass nearly each other in dense environments—namely halo assemblies—they swing and spin each other via exerting mutual tidal torques. We show that this has a significant contribution to the spin of dark matter halos comparable to that calculated by the so-called tidal torque theory. We use the results of the state-of-the-art simulation of Illutris to check the prediction of this theory against the simulation data.

Keywords: Cosmology, Large-scale structure of the universe
Pulse Profile Variations Associated with the Glitch of PSR B2021+51. We reported the first glitch of PSR B2021+51 detected with the Shanghai Tian Ma Radio Telescope that occurred around MJD 58289.1 (2018 June 20). The spin frequency and its derivative suffered a jump of about 7.04 × 10-10 Hz and 2.6 × 10-18 s-2, respectively. The pulse width at the 10% intensity level (W10) of the mean pulse profile significantly decreased right before the glitch and then increased after the glitch, accompanied by an enhancement in the trailing peak of the normalized profile. The mean pulse profiles were decomposed into three Gaussian components, i.e., C1, C2, and C3 from left to right by peak phase. The width of C3 (w3) had an apparent maximum right before the glitch and its weighted mean value became slightly smaller than the pre-glitch value after the glitch, while the weighted mean values of both w1 and w2 had no apparent change. The significant decrease of the mean pulse width right before the glitch is mainly due to the movement of C3 toward C1 and C2, while the increase of the mean pulse width after the glitch results from the movement of C2 toward C3. Changes in the widths of mean pulse profiles and in the widths and phase separations of Gaussian components associated with the glitch convinced us of a connection between the changes in characteristics of the pulsar emission zone and the glitch activity. We discuss a possible interpretation invoking the movements of flux tubes in the emission zone.

Keywords: Neutron stars, Pulsars
New Experimental <SUP>23</SUP>Na(α, p)<SUP>26</SUP>Mg Reaction Rate for Massive Star and Type Ia Supernova Models. The 23Na(α, p)26Mg reaction has been identified as having a significant impact on the nucleosynthesis of several nuclei between Ne and Ti in Type Ia supernovae, and of 23Na and 26Al in massive stars. The reaction has been subjected to renewed experimental interest recently, motivated by high uncertainties in early experimental data and in the statistical Hauser-Feshbach models used in reaction rate compilations. Early experiments were affected by target deterioration issues and unquantifiable uncertainties. Three new independent measurements instead are utilizing inverse kinematics and Rutherford scattering monitoring to resolve this. In this work we present directly measured angular distributions of the emitted protons to eliminate a discrepancy in the assumptions made in the recent reaction rate measurements, which results in cross sections differing by a factor of 3. We derive a new combined experimental reaction rate for the 23Na(α, p)26Mg reaction with a total uncertainty of 30% at relevant temperatures. Using our new 23Na(α, p)26Mg rate, the 26Al and 23Na production uncertainty is reduced to within 8%. In comparison, using the factor of 10 uncertainty previously recommended by the rate compilation STARLIB, 26Al and 23Na production was changing by more than a factor of 2. In Type Ia supernova conditions, the impact on production of 23Na is constrained to within 15%.

Keywords: Nucleosynthesis, Nuclear reaction cross sections, Carbon burning, Nuclear astrophysics, Stellar nucleosynthesis, Nuclear physics
Implications of the Environments of Radio-detected Active Galactic Nuclei in a Complex Protostructure at z ∼ 3.3. Radio active galactic nuclei (RAGNs) are mainly found in dense structures (i.e., clusters/groups) at redshifts of z &lt; 2 and are commonly used to detect protoclusters at higher redshift. Here, we attempt to study the host and environmental properties of two relatively faint (L1.4 GHz ∼ 1025 W Hz-1) RAGNs in a known protocluster at z = 3.3 in the PCl J0227-0421 field, detected using the latest radio observation obtained as part of the Observations of Redshift Evolution in Large-Scale Environments (ORELSE) survey. Using new spectroscopic observations obtained from the Keck/Multi-Object Spectrometer for Infra-Red Exploration as part of the Charting Cluster Construction with the VIMOS Ultra-Deep Survey (VUDS) and ORELSE (C3VO) survey and previous spectroscopic data obtained as part of the VIMOS-Very Large Telescope Deep Survey and VUDS, we revise the three-dimensional overdensity field around this protocluster. The protocluster is embedded in a large-scale overdensity protostructure. This protostructure has an estimated total mass of ∼2.6 × 1015 M☉ and contains several overdensity peaks. Both RAGNs are hosted by very bright and massive galaxies, while their hosts show extreme differences in color, indicating that they are of different ages and are in different evolutionary stages. Furthermore, we find that they are not in the most locally dense parts of the protostructure, but are fairly close to the centers of their parent overdensity peaks. We propose a scenario where merging might have already happened in both cases, which lowered the local density of their surrounding area and boosted their stellar mass. This work is the first time that two RAGNs at low luminosity have been found and studied within a high-redshift protostructure.

Keywords: Radio active galactic nuclei, Protoclusters, Radio galaxies, Galaxy evolution
Observational Evidence for Beat Phenomenon in Complex Solar Type III Radio Bursts. We present new observational evidence for one of the most important three wave interactions, called the electrostatic decay instability (ESD) $L\to {L}^{{\prime} }+S$ in the source regions of complex solar type III radio bursts (L is the electron beam-excited Langmuir wave, and ${L}^{{\prime} }$ and S are the ESD excited daughter Langmuir and ion sound waves, respectively). The STEREO in situ wave observations in the source regions of complex type III bursts show that Langmuir waves often occur as one-dimensional magnetic field aligned beat-type wave packets, with peak intensities well in excess of the threshold for excitation of ESD, and with spectra containing (a) two closely spaced narrow peaks (L and ${L}^{{\prime} }$ ) corresponding probably to the beating modes responsible for the beat patterns at frequencies very close to the local electron plasma frequency, fpe, and (b) narrow peaks at ion sound frequencies, fS, which are very close to beat frequencies. Using the FFT and higher order spectral techniques, we show that the frequency, wavevector and phase resonance conditions required for excitation of ESD are well satisfied for these wave packets, and the speeds of electron beams derived from the resonance conditions agree reasonably well with those derived from the drift rates of the associated type III events. We also show that the merging of (L) and ( ${L}^{{\prime} }$ ) most probably is the excitation mechanism of the second harmonic radio emission ${T}_{2{f}_{{pe}}}$ of these type III bursts.

Keywords: Solar radio flares, Solar radio emission
Cosmic Evolution of the H<SUB>2</SUB> Mass Density and the Epoch of Molecular Gas. We present new empirical constraints on the evolution of ${\rho }_{{{\rm{H}}}_{2}}$ , the cosmological mass density of molecular hydrogen, back to z ≍ 2.5. We employ a statistical approach measuring the average observed 850 μm flux density of near-infrared selected galaxies as a function of redshift. The redshift range considered corresponds to a span where the 850 μm band probes the Rayleigh-Jeans tail of thermal dust emission in the rest frame, and can therefore be used as an estimate of the mass of the interstellar medium. Our sample comprises of ≍150,000 galaxies in the UK InfraRed Telescope Infrared Deep Sky Survey Ultra-Deep Survey field with near-infrared magnitudes KAB ≤ 25 mag and photometric redshifts with corresponding probability distribution functions derived from deep 12-band photometry. With a sample approximately 2 orders of magnitude larger than in previous works we significantly reduce statistical uncertainties on ${\rho }_{{{\rm{H}}}_{2}}$ to z ≍ 2.5. Our measurements are in broad agreement with recent direct estimates from blank field molecular gas surveys, finding that the epoch of molecular gas coincides with the peak epoch of star formation with ${\rho }_{{{\rm{H}}}_{2}}\approx 2\times {10}^{7}\,{M}_{\odot }\,{\mathrm{Mpc}}^{-3}$ at z ≍ 2. We demonstrate that ${\rho }_{{{\rm{H}}}_{2}}$ can be broadly modeled by inverting the star formation rate (SFR) density with a fixed or weakly evolving star formation efficiency. This "constant efficiency" model shows a similar evolution to our statistically derived ${\rho }_{{{\rm{H}}}_{2}}$ , indicating that the dominant factor driving the peak star formation history at z ≍ 2 is a larger supply of molecular gas in galaxies rather than a significant evolution of the SFR efficiency within individual galaxies.

Keywords: Star formation, High-redshift galaxies, Galaxy evolution, Interstellar medium
Long Characteristics versus Short Characteristics in 3D Radiative Transfer Simulations of Polarized Radiation. We compare maps of scattering polarization signals obtained from three-dimensional (3D) radiation transfer calculations in a magnetoconvection model of the solar atmosphere using formal solvers based on the "short characteristics" (SC) and the "long characteristics" (LC) methods. The SC method requires less computational work, but it is known to introduce spatial blurring in the emergent radiation for inclined lines of sight. For polarized radiation this effect is generally more severe due to it being a signed quantity and to the sensitivity of the scattering polarization to the model's inhomogeneities. We study the differences in the polarization signals of the emergent spectral line radiation calculated with such formal solvers. We take as a case study already published results of the scattering polarization in the Sr I 4607 Å line obtained with the SC method, demonstrating that in high-resolution grids it is accurate enough for that type of study. In general, the LC method is the preferred one for accurate calculations of the emergent radiation, which is the reason why it is now one of the options in the public version of the 3D radiative transfer code PORTA.

Keywords: Solar atmosphere, The Sun, Quiet sun, Solar physics, Radiative transfer
Near-IR Observations of the Young Star [BHB2007]-1: A Substellar Companion Opening the Gap in the Disk. The presence of planets or substellar objects still embedded in their native protoplanetary disks is indirectly suggested by disk substructures like gaps, cavities, and spirals. However, these companions are rarely detected. We present Very Large Telescope/NACO high-contrast images in the J, H, KS, and $L^{\prime} $ bands of the young star [BHB2007]-1 probing the inclined disk in scattered light and revealing the probable presence of a companion. The point source is detected in the $L^{\prime} $ band in spatial correspondence with complementary Very Large Array observations. This object is constrained to have a mass in the range of 37-47 MJup and is located at 50 au from the central star, inside the 70 au-large disk cavity recently imaged by the Atacama Large Millimeter/submillimeter Array (ALMA), that is absent from our NACO data (down to 20 au). This mass range is compatible with the upper end derived from the size of the ALMA cavity. The NIR disk brightness is highly asymmetric around the minor axis, with the southern side 5.5 times brighter than the northern side. The constant amount of asymmetry across all wavelengths suggests that it is due to a shadow cast by a misaligned inner disk. The massive companion that we detect could, in principle, explain the possible disk misalignment, as well as the different cavity sizes inferred by the NACO and ALMA observations. The confirmation and characterization of the companion is entrusted to future observations.

Keywords: Exoplanet astronomy, Star formation, Exoplanet systems, Planet hosting stars
MESA Models with Magnetic Braking. Two magnetic braking models are implemented in MESA for use in the MIST stellar model grids. Stars less than about 1.3 solar masses are observed to spin down over time through interaction with their magnetized stellar winds (i.e., magnetic braking). This is the basis for gyrochronology and is fundamental to the evolution of lower-mass stars. The detailed physics behind magnetic braking are uncertain, as are 1D stellar evolution models. Thus, we calibrate our models and compare to data from open clusters. Each braking model tested here is capable of reproducing aspects of the data, with important distinctions; neither fully accounts for the observations. The Matt et al. prescription matches the slowly rotating stars observed in open clusters but tends to overestimate the presence of rapidly rotating stars. The Garraffo et al. prescription often produces too much angular momentum loss to accurately match the observed slow sequence for lower-mass stars but reproduces the bimodal nature of slowly and rapidly rotating stars observed in open clusters fairly well. Our models additionally do not reproduce the observed solar lithium depletion, corroborating previous findings that effects other than rotation may be important. We find additional evidence that some level of mass dependency may be missing in these braking models to match the rotation periods observed in clusters older than 1 Gyr better.

Keywords: Stellar evolutionary models, Stellar physics, Low mass stars, Stellar rotation, Stellar evolution
ALMA Observations of Giant Molecular Clouds in M33. III. Spatially Resolved Features of the Star formation Inactive Million-solar-mass Cloud. We present 12CO (J = 2-1), 13CO (J = 2-1), and C18O (J = 2-1) observations toward GMC-8, one of the most massive giant molecular clouds (GMCs) in M33 using ALMA with an angular resolution of 0"44 × 0"27 (∼2 pc × 1 pc). The earlier studies revealed that its high-mass star formation is inactive in spite of a sufficient molecular reservoir with a total mass of ∼106 M⊙. The high-angular resolution data enable us to resolve this peculiar source down to a molecular clump scale. One of the GMC's remarkable features is that a round-shaped gas structure (the "Main cloud") extends over the ∼50 pc scale, which is quite different from the other two active star-forming GMCs dominated by remarkable filaments/shells obtained by our series of studies in M33. The fraction of the relatively dense gas traced by the 13CO data with respect to the total molecular mass is only ∼2%, suggesting that their spatial structure and the density are not well developed to reach an active star formation. The CO velocity analysis shows that the GMC is composed of a single component as a whole, but we found some local velocity fluctuations in the Main cloud and extra blueshifted components at the outer regions. Comparing the CO with previously published large-scale H I data, we suggest that an external atomic gas flow supplied a sufficient amount of material to grow the GMC up to ∼106 M⊙.

Keywords: Local Group, Molecular gas, Interstellar atomic gas, Giant molecular clouds, Triangulum Galaxy, Star formation, Interstellar medium