adsabs/SciX_UAT_keywords huggingface dataset:
The Cosmic History of Long Gamma-Ray Bursts

The cosmic formation rate of long gamma-ray bursts (LGRBs) encodes the evolution, across cosmic times, of the properties of their progenitors and of their environment. The LGRB formation rate and the luminosity function, with its redshift evolution, are derived by reproducing the largest sets of observations collected over the last four decades, namely the observer-frame prompt emission properties of the GRB samples detected by the Fermi and Compton Gamma Ray Observatory satellites and the redshift, luminosity, and energy distributions of the flux-limited, redshift-complete samples of GRBs detected by Swift. The model that best reproduces all these constraints consists of a GRB formation rate increasing with redshift ∝(1 + z)3.2, i.e., steeper than the star formation rate, up to z ~ 3, followed by a decrease ∝(1 + z)-3. On top of this, our model also predicts a moderate evolution of the characteristic luminosity function break ∝(1 + z)0.6. Models with only luminosity or rate evolution are excluded at >5σ significance. The cosmic rate evolution of LGRBs is interpreted as their preference for occurring in environments with metallicity $12+\mathrm{log}({\rm{O}}/{\rm{H}})\lt 8.6$ , consistent with theoretical models and host galaxy observations. The LGRB rate at z = 0, accounting for their collimation, is ${\rho }_{0}\,=\,{79}_{-33}^{+57}$ Gpc-3 yr-1 (68% confidence interval). This corresponds to ~1% of broad-line Type Ibc supernovae producing a successful jet in the local universe. This fraction increases up to ~7% at z ≥ 3. Finally, we estimate that at least ≈0.2-0.7 yr-1 of the Swift- and Fermi-detected bursts at z < 0.5 are jets observed slightly off-axis.

Keywords: gamma-ray bursts; star formation
The Dynamic Structure of Coronal Hole Boundaries

The boundaries of solar coronal holes are difficult to uniquely define observationally but are sites of interest in part because the slow solar wind appears to originate there. The aim of this article is to explore the dynamics of interchange magnetic reconnection at different types of coronal hole boundaries-namely streamers and pseudostreamers-and their implications for the coronal structure. We describe synthetic observables derived from three-dimensional magnetohydrodynamic simulations of the atmosphere of the Sun in which coronal hole boundaries are disturbed by flows that mimic the solar supergranulation. Our analysis shows that interchange reconnection takes place much more readily at the pseudostreamer boundary of the coronal hole. As a result, the portion of the coronal hole boundary formed by the pseudostreamer remains much smoother, in contrast to the highly distorted helmet-streamer portion of the coronal hole boundary. Our results yield important new insights on coronal hole boundary regions, which are critical in coupling the corona to the heliosphere as the formation regions of the slow solar wind.

Keywords: solar physics; solar magnetic reconnection; solar corona; solar coronal holes; slow solar wind; magnetohydrodynamics
Assessing the Evolution of Solar Cycle 25: A Weak-moderate Cycle

This note aims to analyze the evolution of the sunspot number for Solar Cycle 25, updating our previous findings on this topic. We compare daily, monthly and 13 months smoothed sunspot numbers for Solar Cycle 25 with those from previous cycles since mid-18th century (Solar Cycles 1–25). The highest daily, monthly and 13 months smoothed values for Solar Cycle 25 are significantly lower than the mean and median values considering all cycles. In particular, Solar Cycle 25 ranks 17th in terms of the highest 13 months smoothed sunspot number at this point in the cycle. Based on current data and the progression toward its maximum, we conclude that Solar Cycle 25 is likely to be a weak to moderate cycle, consistent with our earlier analyses. In addition, we find that Solar Cycles 13, 14, and 16 have the most similar behavior to that of Solar Cycle 25. Assuming a cycle length for Solar Cycle 25 similar to those of the above cycles, we estimate that the minimum of Solar Cycle 26 will be in 2030–2031.

Keywords: sunspot number; solar activity; solar cycle; sunspot cycle
Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample. VI. Evidence for the Long-lived Nonsteady Warp of Nongravitational Scenarios

By combining LAMOST DR4 and Gaia DR2 common red clump stars with age and proper motion, we analyze the amplitude evolution of the stellar warp independently of any assumption with a simple model. The greatest height of the warp disk increases with galactocentric distance in different populations and is dependent on age: the younger stellar populations exhibit stronger warp features than the old ones, accompanied by the warp amplitude γ (age) decreasing with age, and its first derivative $\dot{\gamma }(\mathrm{age})$ is different from zero. The azimuth of the line of nodes φw is stable at -5° without clear time evolution, which perfectly confirms some previous works. All of this self-consistent evidence supports that our Galactic warp should most likely be a long-lived but nonsteady structure and not a transient one, which is supporting that the warp originated from gas infall onto the disk or other hypotheses that suppose that the warp mainly affects the gas, and consequently, younger populations tracing the gas are stronger than older ones. In other words, the Galactic warp is induced by the nongravitational interaction over the disk models.

Keywords: milky way disk; milky way dynamics; milky way galaxy
Libration-induced Orbit Period Variations Following the DART Impact

The Double Asteroid Redirection Test (DART) mission will be the first test of a kinetic impactor as a means of planetary defense. In late 2022, DART will collide with Dimorphos, the secondary in the Didymos binary asteroid system. The impact will cause a momentum transfer from the spacecraft to the binary asteroid, changing the orbit period of Dimorphos and forcing it to librate in its orbit. Owing to the coupled dynamics in binary asteroid systems, the orbit and libration state of Dimorphos are intertwined. Thus, as the secondary librates, it also experiences fluctuations in its orbit period. These variations in the orbit period are dependent on the magnitude of the impact perturbation, as well as the system's state at impact and the moments of inertia of the secondary. In general, any binary asteroid system whose secondary is librating will have a nonconstant orbit period on account of the secondary's fluctuating spin rate. The orbit period variations are typically driven by two modes: a long period and a short period, each with significant amplitudes on the order of tens of seconds to several minutes. The fluctuating orbit period offers both a challenge and an opportunity in the context of the DART mission. Orbit period oscillations will make determining the post-impact orbit period more difficult but can also provide information about the system's libration state and the DART impact.

Keywords: asteroid dynamics; asteroid satellites; celestial mechanics; orbital evolution
Not So Windy After All: MUSE Disentangles AGN-driven Winds from Merger-induced Flows in Galaxies along the Starburst Sequence

Poststarburst galaxies are believed to be in a rapid transition between major merger starbursts and quiescent ellipticals, where active galactic nucleus (AGN) feedback is suggested as one of the processes responsible for the quenching. To study the role of AGN feedback, we constructed a sample of poststarburst candidates with AGN and indications of ionized outflows in optical. We use MUSE/VLT observations to spatially resolve the properties of the stars and multiphase gas in five of them. All galaxies show signatures of interaction/merger in their stellar or gas properties, with some at an early stage of interaction with companions ∼50 kpc, suggesting that optical poststarburst signatures may be present well before the final starburst and coalescence. We detect narrow and broad kinematic components in multiple transitions in all the galaxies. Our detailed analysis of their kinematics and morphology suggests that, contrary to our expectation, the properties of the broad kinematic components are inconsistent with AGN-driven winds in three out of five galaxies. The two exceptions are also the only galaxies in which spatially resolved NaID P-Cygni profiles are detected. In some cases, the observations are more consistent with interaction-induced galactic-scale flows, an often overlooked process. These observations raise the question of how to interpret broad kinematic components in interacting and perhaps also in active galaxies, in particular when spatially resolved observations are not available or cannot rule out merger-induced galactic-scale motions. We suggest that NaID P-Cygni profiles are more effective outflow tracers, and use them to estimate the energy that is carried by the outflow.

Keywords: agn host galaxies; active galaxies; e+a galaxies; luminous infrared galaxies; starburst galaxies; galactic winds; supermassive black holes; galaxy mergers; active galactic nuclei
Sun-like Stars Shed Light on Solar Climate Forcing

Recently published precise stellar photometry of 72 Sun-like stars obtained at the Fairborn Observatory between 1993 and 2017 is used to set limits on the solar forcing of Earth's atmosphere of ±4.5 W m-2 since 1750. This compares with the +2.2 ± 1.1 W m-2 IPCC estimate for anthropogenic forcing. Three critical assumptions are made. In decreasing order of importance they are: (a) most of the brightness variations occur within the average time series length of ≈17 yr; (b) the Sun seen from the ecliptic behaves as an ensemble of middle-aged solar-like stars; and (c) narrowband photometry in the Strömgren b and y bands are linearly proportional to the total solar irradiance. Assumption (a) can best be relaxed and tested by obtaining more photometric data of Sun-like stars, especially those already observed. Eight stars with near-solar parameters have been observed from 1999, and two since 1993. Our work reveals the importance of continuing and expanding ground-based photometry, to complement expensive solar irradiance measurements from space.

Keywords: the sun; solar analogs; solar spectral irradiance
Noble Gas Planetology and the Xenon Clouds of Uranus

Noble gases provide tracers of cosmic provenance that are accessible to a future Uranus atmospheric probe. Argon and krypton are expected to be well mixed on Uranus with respect to H2 and He, although condensation at the winter pole may be possible. The Ar/H2 and Ar/Kr ratios address whether the materials accreted by Uranus resembled the extremely cold materials accreted by Jupiter's atmosphere, whether they were warmer, like comet 67P/Churyumov–Gerasimenko (67P/C-G), or whether Uranus is like neither. Xenon condenses as an ice, probably on methane ice, in Uranus's upper troposphere. Condensation may complicate the interpretation of Xe/H2, but it also presents an opportunity to collect concentrated xenon samples suitable for measuring isotopes. Solar system Xe tracks three distinct nucleosynthetic xenon reservoirs, one evident in the Sun and in chondritic meteorites, a second in refractory presolar grains, and a third evident in comet 67P/C-G and in Earth's air. The first and third reservoirs appear to have been captured from different clouds of gas. The two gases do not appear to have been well mixed; moreover, the high 129Xe/132Xe ratio in 67P/C-G implies that the gas was captured before the initial nucleosynthetic complement of 129I (15.7 Myr half-life) had decayed. Xenon's isotopic peculiarities, if seen in Uranus, could usefully upset our understanding of planetary origins. Krypton's isotopic anomalies are more subtle and may prove hard to measure. There is a slight chance that neon and helium fractionations can be used to constrain how Uranus acquired its nebular envelope.

Keywords: uranus; solar system; chemical abundances; isotopic abundances; atmospheric clouds
The Dynamics of the Magnetic-field-free Cavity around Comets

The diamagnetic cavity is the innermost region of the magnetosphere of an active comet, from which the magnetic field is expelled by the outflowing matter. This phenomenon, first detected around comet 1P/Halley, was extensively studied recently by the Rosetta comet chaser mission. Rosetta observed a surprisingly large diamagnetic cavity around comet 67P/Churyumov-Gerasimenko and revealed an unforeseen structure, rich and highly dynamic. Here we present a simple (1+1)-dimensional analytic MHD model of the diamagnetic cavity, which for the first time explains the unexpected size and variability of the cavity. In this model, inward and outward moving time-dependent solutions emerge, featuring distinct differences, in accordance with observations. The plasma density is enhanced in the entire magnetized region. The density enhancement is more pronounced for weak comets, resulting in a stronger interaction and hence the larger than expected cavity. Space weather effects determine the asymptotic plasma speed, thus driving the variations of the plasma properties observed near the cavity.

Keywords: comets; ionized coma gases; neutral coma gases; interplanetary magnetic fields; space plasmas
The AGORA High-resolution Galaxy Simulations Comparison Project. V. Satellite Galaxy Populations in a Cosmological Zoom-in Simulation of a Milky Way–Mass Halo

We analyze and compare the satellite halo populations at z ∼ 2 in the high-resolution cosmological zoom-in simulations of a 1012 M ⊙ target halo (z = 0 mass) carried out on eight widely used astrophysical simulation codes (ART-I, ENZO, RAMSES, CHANGA, GADGET-3, GEAR, AREPO-T, and GIZMO) for the AGORA High-resolution Galaxy Simulations Comparison Project. We use slightly different redshift epochs near z = 2 for each code (hereafter "z ∼ 2") at which the eight simulations are in the same stage in the target halo's merger history. After identifying the matched pairs of halos between the CosmoRun simulations and the DMO simulations, we discover that each CosmoRun halo tends to be less massive than its DMO counterpart. When we consider only the halos containing stellar particles at z ∼ 2, the number of satellite galaxies is significantly fewer than that of dark matter halos in all participating AGORA simulations and is comparable to the number of present-day satellites near the Milky Way or M31. The so-called "missing satellite problem" is fully resolved across all participating codes simply by implementing the common baryonic physics adopted in AGORA and the stellar feedback prescription commonly used in each code, with sufficient numerical resolution (≲100 proper pc at z = 2). We also compare other properties such as the stellar mass–halo mass relation and the mass–metallicity relation. Our work highlights the value of comparison studies such as AGORA, where outstanding problems in galaxy formation theory are studied simultaneously on multiple numerical platforms.

Keywords: galaxy formation; astronomical simulations; hydrodynamical simulations; dwarf galaxies
Long-term Quasiperiodicity in LMXB 4U 1636-536

We present the results of the low-mass X-ray binary 4U 1636-536 study. We performed a temporal analysis of all available RXTE/All-Sky Monitor, RXTE/Proportional Counter Array, Swift/Burst Alert Telescope, and MAXI data collected until the middle of 2022. Within our analysis we confirmed the previously discovered quasiperiodicity of ≃45 days present during ~2004, and we found that it continued until 2007. Moreover, we showed that similar periodicity also appeared in 2010 and 2011. At other epochs, the quasiperiodicity is only transient. We applied a time-dependent accretion disk model to the interval with the most significant X-ray quasiperiodicity. Although 4U 1636-536 is persistent, the observed quasiperiodicity can be well modeled by the hydrogen thermal-ionization instability occurring in the outer regions of the accretion disk. For our best model, the theoretical light curve's period and amplitude agree well with those observed.

Keywords: x-ray astronomy; x-ray binary stars; low-mass x-ray binary stars; neutron stars; accretion; stellar accretion disks
Chromospheric Carbon Monoxide Formation around a Solar Pore

We present observations of NOAA AR 11159, obtained on 2011 February 14 in the 4.7 μm band of carbon monoxide (CO) and coordinated with spectroscopic imaging of three atomic lines (Na I 5896 Å, Fe I 7090 Å, and Ca II 8542 Å) which sample heights from the mid-photosphere to the chromosphere. Phase-difference spectra between the observed spectral lines instead indicate that the CO lines form at z ≈ 530-650 km in the quiet Sun. During the two hours of observations, seven long-lived cooling events ("cold bubbles") were observed in CO in the region surrounding a large pore, but were not visible in the three atomic lines. These events show self-similar temporal evolution with time scales consistent with the chemical formation rate of CO at z ≈ 1000 km. Due to the lack of such features in the surrounding quiet Sun, we hypothesize that the magnetic canopy field surrounding the pore, which suppresses the upward propagation of acoustic waves into the chromosphere and the subsequent formation of shocks, depresses the rate of acoustic heating and allows CO to condense and cool the atmosphere at those heights. These "cold bubbles" may be a source of the chromospheric CO that produces the unexpectedly high (z ≈ 1000 km) limb extensions seen in the stronger CO lines, and may provide a unique opportunity to study this enigmatic component of the solar atmosphere in spatially resolved observations.

Keywords: solar atmosphere; solar physics; solar chromosphere; molecular spectroscopy; atomic spectroscopy; solar photosphere; observational astronomy
The Intrinsic Multiplicity Distribution of Exoplanets Revealed from the Radial Velocity Method

Planet multiplicities are useful in constraining the formation and evolution of planetary systems, but they are usually difficult to constrain observationally. Here, we develop a general method that can properly take into account the survey incompleteness and recover the intrinsic planet multiplicity distribution. We then apply it to the radial velocity (RV) planet sample from the California Legacy Survey (CLS). Within the 1 au (10 au) region, we find 21% ± 4% (19.2% ± 2.8%) of Sun-like stars host planets with masses above 10 M ⊕ (0.3 M J), about 30% (40%) of which are multiplanet systems; in terms of the RV semi-amplitude K, 33% ± 7% (25% ± 3%) of Sun-like stars contain planets of K > 1 m s-1 (3 m s-1), and each system hosts on average 1.8 ± 0.4 (1.63 ± 0.16) planets. We note that the hot Jupiter rate in the CLS Sun-like sample is higher than the consensus value of ~1% by a factor of about three. We also confirm previous studies on the correlation between inner ( <1 au) and outer ( >1 au) planets.

Keywords: exoplanets; exoplanet systems; radial velocity
PHANGS CO Kinematics: Disk Orientations and Rotation Curves at 150 pc Resolution

We present kinematic orientations and high-resolution (150 pc) rotation curves for 67 main-sequence star-forming galaxies surveyed in CO (2-1) emission by PHANGS-ALMA. Our measurements are based on the application of a new fitting method tailored to CO velocity fields. Our approach identifies an optimal global orientation as a way to reduce the impact of nonaxisymmetric (bar and spiral) features and the uneven spatial sampling characteristic of CO emission in the inner regions of nearby galaxies. The method performs especially well when applied to the large number of independent lines of sight contained in the PHANGS CO velocity fields mapped at 1″ resolution. The high-resolution rotation curves fitted to these data are sensitive probes of mass distribution in the inner regions of these galaxies. We use the inner slope as well as the amplitude of our fitted rotation curves to demonstrate that CO is a reliable global dynamical mass tracer. From the consistency between photometric orientations from the literature and kinematic orientations determined with our method, we infer that the shapes of stellar disks in the mass range of log( ${M}_{\star }({M}_{\odot })$ ) = 9.0-10.9 probed by our sample are very close to circular and have uniform thickness.

Keywords: molecular clouds; galaxy dynamics; interstellar medium
Effects of Close Binary Evolution on the Main-sequence Morphology of Young Star Clusters

Star clusters are the building blocks of galaxies. They are composed of stars of nearly equal age and chemical composition, allowing us to use them as chronometers and as testbeds for gauging stellar evolution. It has become clear recently that massive stars are formed preferentially in close binaries, in which mass transfer will drastically change the evolution of the stars. This is expected to leave a significant imprint in the distribution of cluster stars in the Hertzsprung-Russell diagram. Our results, based on a dense model grid of more than 50,000 detailed binary-evolution calculations, show several distinct, coeval main-sequence (MS) components, most notably an extended MS turnoff region, and a group of near-critical rotating stars that is spread over a large luminosity range on the red side of the classical MS. We comprehensively demonstrate the time evolution of the features in an animation, and we derive analytic expressions to describe these features. We find quantitative agreement with results based on recent photometric and spectroscopic observations. We conclude that while other factors may also be at play, binary evolution has a major impact on the MS morphology of young star clusters.

Keywords: stellar evolution; close binary stars; interacting binary stars; stellar evolutionary models
New Close Binary Central Stars of Planetary Nebulae from Gaia DR3 Epoch Photometry

Close binary interactions perform a key role in the formation and shaping of planetary nebulae (PNe). However only a small fraction of Galactic PNe are known to host close binary systems. Many such systems are detectable through photometric variability. We searched recently published epoch photometry data from Gaia DR3 for planetary nebula central stars with periodic photometric variability indicative of binarity, uncovering four previously unknown close binaries.

Keywords: planetary nebulae; planetary nebulae nuclei; common envelope binary stars; gaia
Double White Dwarf Merger Products among High-mass White Dwarfs

Double white dwarf (double-WD) binaries may merge within a Hubble time and produce high-mass WDs. Compared to other high-mass WDs, the double-WD merger products have higher velocity dispersion because they are older. With the power of Gaia data, we show strong evidence for double-WD merger products among high-mass WDs by analyzing the transverse-velocity distribution of more than 1000 high-mass WDs (0.8-1.3 M⊙). We estimate that the fraction of double-WD merger products in our sample is about 20%. We also obtain a precise double-WD merger rate and its mass dependence. Our merger rate estimates are close to binary population synthesis results and support the idea that double-WD mergers may contribute to a significant fraction of type Ia supernovae.

Keywords: white dwarf stars; stellar kinematics; stellar ages; type ia supernovae; bayesian statistics