adsabs/SciX_UAT_keywords huggingface dataset:
Limits on Neutrino Emission from GRB 221009A from MeV to PeV Using the IceCube Neutrino Observatory

Gamma-ray bursts (GRBs) have long been considered a possible source of high-energy neutrinos. While no correlations have yet been detected between high-energy neutrinos and GRBs, the recent observation of GRB 221009A-the brightest GRB observed by Fermi-GBM to date and the first one to be observed above an energy of 10 TeV-provides a unique opportunity to test for hadronic emission. In this paper, we leverage the wide energy range of the IceCube Neutrino Observatory to search for neutrinos from GRB 221009A. We find no significant deviation from background expectation across event samples ranging from MeV to PeV energies, placing stringent upper limits on the neutrino emission from this source.

Keywords: neutrino telescopes; gamma-ray bursts; particle astrophysics
Physical Properties of the Asteroid Belts from Brightness-limited Surveys

We introduce a general debiasing Bayesian formalism to brightness-limited surveys of solar system objects that constrains the statistical distribution of a population's physical characteristics such as size, albedo, heliocentric distance, or others to account for the survey detections and measured properties such as brightness. We reanalyze the Dark Energy Camera search for main-belt asteroids of Peña et al. and fit a smooth double power-law size to its size distribution. Using only detections with reliable distances and accurate orbital information, we find no evidence for a significant difference in size distribution between the inner, middle, and outer belts for objects between 0.1 and 1 km in diameter, with q 2 = 2.27 ± 0.05 a good fit for the small-end slope. We show that the intrinsic number density of objects is consistent between these populations and is compatible with observational biases. As spectral classes are distributed unevenly throughout the main belt, these results support the ongoing collisional reprocessing of the asteroid belt for objects smaller than 5 km.

Keywords: small solar system bodies; surveys
CEERS Key Paper. III. The Diversity of Galaxy Structure and Morphology at z = 3-9 with JWST

We present a comprehensive analysis of the evolution of the morphological and structural properties of a large sample of galaxies at z = 3-9 using early James Webb Space Telescope (JWST) CEERS NIRCam observations. Our sample consists of 850 galaxies at z > 3 detected in both Hubble Space Telescope (HST)/WFC3 and CEERS JWST/NIRCam images, enabling a comparison of HST and JWST morphologies. We conduct a set of visual classifications, with each galaxy in the sample classified three times. We also measure quantitative morphologies across all NIRCam filters. We find that galaxies at z > 3 have a wide diversity of morphologies. Galaxies with disks make up 60% of galaxies at z = 3, and this fraction drops to ~30% at z = 6-9, while galaxies with spheroids make up ~30%-40% across the redshift range, and pure spheroids with no evidence for disks or irregular features make up ~20%. The fraction of galaxies with irregular features is roughly constant at all redshifts (~40%-50%), while those that are purely irregular increases from ~12% to ~20% at z > 4.5. We note that these are apparent fractions, as many observational effects impact the visibility of morphological features at high redshift. On average, Spheroid-only galaxies have a higher Sérsic index, smaller size, and higher axis ratio than disk or irregular galaxies. Across all redshifts, smaller spheroid and disk galaxies tend to be rounder. Overall, these trends suggest that galaxies with established disks and spheroids exist across the full redshift range of this study, and further work with large samples at higher redshift is needed to quantify when these features first formed.

Keywords: galaxy evolution; galaxy classification systems; galaxies; disk galaxies; irregular galaxies; hubble classification scheme
A Catalog of Young Stellar Objects from the LAMOST and ZTF Surveys

As astronomical data sets become too large for traditional analysis approaches, more machine-learning algorithms are employed in astronomy. A wealth of light variation data have been accumulated, which provide rich samples for astronomers to study variable stars. Facing the challenge of big data, this article takes the classification of variable and transient objects observed by the Zwicky Transient Facility (ZTF) as the main goal, and a self-paced ensemble (SPE) imbalanced-learning classifier is constructed to separate different classes. The performance of the classifier reveals that SPE is better than a traditional imbalanced-learning algorithm for the minority classes. In our work, the SPE classifier is satisfactory for young stellar objects (YSOs), and the completeness (recall) of YSOs is enhanced to 91%. As a result, 868,371 ZTF sources are classified into 15 classes by this classifier, which contains 8210 YSO candidates (YSO_prob ≥ 0.70). In order to further identify YSO candidates, these candidates are crossmatched with LAMOST DR9. Finally, 833 candidates are observed by LAMOST, among them 379 objects that are known YSOs in SIMBAD. For the remaining objects with good-quality LAMOST spectra, we visually check their spectral characteristics, and 238 objects are newly confirmed YSOs. These newfound YSOs supplement the present YSO sample, and other YSO candidates may be used for follow-up observation, which is useful for characterizing YSOs, finding more YSOs, and then giving a better stellar evolution model in the future. The classified ZTF sources by SPE provide reference to the study of variables and transients.

Keywords: astronomy data analysis; astrostatistics techniques; time series analysis; light curve classification; pre-main sequence stars
Coronal Mass Ejections and Dimmings: A Comparative Study Using MHD Simulations and SDO Observations

Solar coronal dimmings have been observed extensively in recent years. Due to their close association with coronal mass ejections (CMEs), there is a critical need to improve our understanding of the physical processes that cause dimmings as well as their relationship with CMEs. In this study, we investigate coronal dimmings by combining simulation and observational efforts. By utilizing a data-constrained global magnetohydrodynamics model (Alfvén-wave solar model), we simulate coronal dimmings resulting from different CME energetics and flux rope configurations. We synthesize the emissions of different EUV spectral bands/lines and compare with SDO/AIA and EVE observations. A detailed analysis of the simulation and observation data suggests that the transient dimming/brightening are related to plasma heating processes, while the long-lasting core and remote dimmings are caused by mass-loss process induced by the CME. Moreover, the interaction between the erupting flux rope with different orientations and the global solar corona could significantly influence the coronal dimming patterns. Using metrics such as dimming depth and dimming slope, we investigate the relationship between dimmings and CME properties (e.g., CME mass, CME speed) in the simulation. Our result suggests that coronal dimmings encode important information about the associated CMEs, which provides a physical basis for detecting stellar CMEs from distant solar-like stars.

Keywords: solar coronal mass ejections; solar wind; solar corona
A Spectroscopic Analysis of the California-Kepler Survey Sample. II. Correlations of Stellar Metallicities with Planetary Architectures

We present independent and self-consistent metallicities for a sample of 807 planet-hosting stars from the California-Kepler Survey from an LTE spectroscopic analysis using a selected sample of Fe I and Fe II lines. Correlations between host-star metallicities, planet radii, and planetary architecture (orbital periods-warm or hot-and multiplicity-single or multiple) were investigated using nonparametric statistical tests. In addition to confirming previous results from the literature, e.g., that overall host-star metallicity distributions differ between hot and warm planetary systems of all types, we report on a new finding: when comparing the median metallicities of hot versus warm systems, the difference for multiple super-Earths is considerably larger when compared to that difference in single super-Earths. The metallicity cumulative distribution functions of hot single super-Earths versus warm single super-Earths indicate different parent stellar populations, while for sub-Neptunes this is not the case. The transition radius between sub-Neptunes and sub-Saturns was examined by comparing the APOGEE metallicity distribution for the Milky Way thin disk in the solar neighborhood with metallicity distributions of host stars segregated based upon the largest known planet in their system. These comparisons reveal increasingly different metallicity distributions as the radius of the largest planet in the systems increases, with the parent stellar metallicities becoming significantly different for Rp > 2.7 R⊕. The behavior of the p-values as a function of planet radius undergoes a large slope change at Rp = 4.4 ± 0.5 R⊕, indicating the radius boundary between small and large planets.

Keywords: fundamental parameters of stars; planetary system formation; high resolution spectroscopy; stellar atmospheres; stellar abundances
Rapid Expansion of the Young Type Ia Supernova Remnant 0519-69.0: More Evidence for a Circumstellar Shell

The nature of Type Ia supernovae remains controversial. The youngest remnants of Ia supernovae hold clues to the explosion and to the immediate surroundings. We present a third epoch of Chandra observations of the ~600 yr old Type Ia remnant 0519-69.0 in the Large Magellanic Cloud, extending the time baseline to 21 yr from the initial 2000 observations. We find rapid expansion of X-ray emitting material, with an average velocity of 4760 km s-1. At the distance of the LMC, this corresponds to an undecelerated age of 750 yr, with the true age somewhat lower. We also find that the bright ring of emission has expanded by 1.3%, corresponding to a velocity of 1900 km s-1 and an undecelerated age of 1600 yr. The high velocity of the peripheral X-rays, contrasted with the modest expansion of the main X-ray shell, provides further evidence for a massive shell of circumstellar material.

Keywords: interstellar medium; supernova remnants
On the Properties of Inverse Compton Spectra Generated by Upscattering a Power-law Distribution of Target Photons

Relativistic electrons are an essential component in many astrophysical sources, and their radiation may dominate the high-energy bands. Inverse Compton (IC) emission is the radiation mechanism that plays the most important role in these bands. The basic properties of IC, such as the total and differential cross sections, have long been studied; the properties of the IC emission depend strongly not only on the emitting electron distribution but also on the properties of the target photons. This complicates the phenomenological studies of sources, where target photons are supplied from a broad radiation component. We study the spectral properties of IC emission generated by a power-law distribution of electrons on a power-law distribution of target photons. We approximate the resulting spectrum by a broken-power-law distribution and show that there can be up to three physically motivated spectral breaks. If the target photon spectrum extends to sufficiently low energies, ${\varepsilon }_{\min }\lt {m}_{e}^{2}{c}^{4}/{E}_{\max }$ (m e and c are electron mass and speed of light, respectively; ${\varepsilon }_{\min }$ and ${E}_{\max }$ are the minimum/maximum energies of target photons and electrons, respectively), then the high-energy part of the IC component has a spectral slope typical for the Thomson regime with an abrupt cutoff close to ${E}_{\max }$ . The spectra typical for the Klein-Nishina regime are formed above ${m}_{e}^{2}{c}^{4}/{\varepsilon }_{\min }$ . If the spectrum of target photons features a cooling break, i.e., a change of the photon index by 0.5 at ɛ br, then the transition to the Klein-Nishina regime proceeds through an intermediate change of the photon index by 0.5 at ${m}_{e}^{2}{c}^{4}/{\varepsilon }_{\mathrm{br}}$ .

Keywords: gamma-ray sources; gamma-ray bursts; gamma-ray transient sources; gamma-rays
Large-scale Structures in the CANDELS Fields: The Role of the Environment in Star Formation Activity

We present a robust method, weighted von Mises kernel density estimation, along with boundary correction to reconstruct the underlying number density field of galaxies. We apply this method to galaxies brighter than Hubble Space Telescope $/{\rm{F}}160{\rm{w}}\leqslant 26$ AB mag in the redshift range 0.4 ≤ z ≤ 5 in the five CANDELS fields (GOODS-N, GOODS-S, EGS, UDS, and COSMOS). We then use these measurements to explore the environmental dependence of the star formation activity of galaxies. We find strong evidence of environmental quenching for massive galaxies (M ≳ 1011 M⊙) out to z ∼ 3.5 such that an overdense environment hosts ≳20% more massive quiescent galaxies than an underdense region. We also find that environmental quenching efficiency grows with stellar mass and reaches ∼60% for massive galaxies at z ∼ 0.5. The environmental quenching is also more efficient than stellar mass quenching for low-mass galaxies (M ≲ 1010 M⊙) at low and intermediate redshifts (z ≲ 1.2). Our findings concur thoroughly with the "overconsumption" quenching model where the termination of cool gas accretion (cosmological starvation) happens in an overdense environment and the galaxy starts to consume its remaining gas reservoir in depletion time. The depletion time depends on the stellar mass and could explain the evolution of environmental quenching efficiency with stellar mass.

Keywords: galaxy environments; galaxy evolution; large-scale structure of the universe; galaxy quenching
A New Low-beta Regime for Unstable Proton Firehose Modes in Bi-kappa-distributed Plasmas

In the solar-wind plasma an excess of kinetic temperature along the background magnetic field stimulates proton firehose modes to grow if the parallel plasma beta parameter is sufficiently high, i.e., βp∥ ≳ 1. This instability can prevent the expansion-driven anisotropy from increasing indefinitely and explain the observations. Moreover, such kinetic instabilities are expected to be even more effective in the presence of suprathermal Kappa-distributed populations, which are ubiquitous in the solar wind and are less affected by collisions than the core population but contribute with an additional free energy. In this work we use both linear and extended quasi-linear (QL) frameworks to characterize the unstable periodic proton firehose modes (propagating parallel to the magnetic field) under the influence of suprathermal protons. Linear theory predicts a systematic stimulation of the instability, suprathermals amplifying the growth rates and decreasing the instability thresholds to lower anisotropies and lower plasma betas (βp∥ < 1). In perfect agreement with these results, the QL approach reveals a significant enhancement of the resulting electromagnetic fluctuations up to saturation with a stronger back reaction on protons, leading also to a faster and more efficient relaxation of the temperature anisotropy.

Keywords: solar wind; space plasmas
The Effect of Supernovae on the Turbulence and Dispersal of Molecular Clouds

We study the impact of supernovae on individual molecular clouds, using a high-resolution magnetohydrodynamic simulation of a 250 pc region where we resolve the formation of individual massive stars. The supernova feedback is implemented with real supernovae, meaning supernovae that are the natural evolution of the resolved massive stars, so their position and timing are self-consistent. We select a large sample of molecular clouds from the simulation to investigate the supernova energy injection and the resulting properties of molecular clouds. We find that molecular clouds have a lifetime of a few dynamical times, less than half of them contract to the point of becoming gravitationally bound, and the dispersal time of bound clouds of order one dynamical time is a factor of 2 shorter than that of unbound clouds. We stress the importance of internal supernovae, that is, massive stars that explode inside their parent cloud, in setting the cloud dispersal time, and their huge overdensity compared to models where the supernovae are randomly distributed. We also quantify the energy injection efficiency of supernovae as a function of supernova distance to the clouds. We conclude that intermittent driving by supernovae can maintain molecular cloud turbulence and may be the main process for cloud dispersal and that the full role of supernovae in the evolution of molecular clouds cannot be fully accounted for without a self-consistent implementation of the supernova feedback.

Keywords: magnetohydrodynamics; computational methods; molecular clouds; giant molecular clouds; supernova remnants
Truth or Delusion? A Possible Gravitational Lensing Interpretation of the Ultraluminous Quasar SDSS J010013.02+280225.8 at z = 6.30

Gravitational lensing sometimes dominates the observed properties of apparently very bright objects. We present morphological properties in the high-resolution (FWHM ∼ 0"15) Atacama Large Millimeter/submillimeter Array (ALMA) 1 mm map for an ultraluminous quasar at z = 6.30, SDSS J010013.02+280225.8 (hereafter J0100+2802), whose black hole (BH) mass MBH is the most massive (∼1.2 × 1010M⊙) at z > 6 ever known. We find that the continuum emission of J0100+2802 is resolved into a quadruple system within a radius of 0"2, which can be interpreted as either multiple dusty star-forming regions in the host galaxy or multiple images due to strong gravitational lensing. The Mg II absorption and the potential Lyα line features have been identified at z = 2.33 in the near-infrared spectroscopy toward J0100+2802, and a simple mass model fitting well reproduces the positions and flux densities of the quadruple system, both of which are consistent with the latter interpretation. Although a high-resolution map taken in the Advanced Camera for Survey on board Hubble Space Telescope (HST) shows a morphology with an apparently single component, in our fiducial lens mass model it can simply be explained by a ∼50 pc scale offset between the ALMA and HST emission regions. In this case, the magnification factor for the observed HST emission is obtained to ∼450, reducing the intrinsic MBH estimate to below 109 M⊙. The confirmation or the rejection of the gravitational lensing scenario is important for our understanding of the supermassive BHs in the early universe.

Keywords: supermassive black holes; quasars; gravitational lensing; early universe
High-resolution Transmission Spectroscopy of Ultrahot Jupiter WASP-33b with NEID

We report an attempt to detect molecular and atomic species in the atmosphere of the ultrahot Jupiter WASP-33b using the high-resolution echelle spectrograph NEID with a wavelength coverage of 380-930 nm. By analyzing the transmission spectrum of WASP-33b using the line-by-line technique and the cross-correlation technique, we confirm previous detection of Hα, Hβ, Hγ, and Ca II infrared triplets. We find no evidence for a significant day-to-night wind in WASP-33b, taking into account the effects of stellar pulsations using a relatively novel Gaussian process method and poorly constrained systemic velocity measurements. We also detect the previously reported pretransit absorption signal, which may be a pulsation mode induced by the planet. Combined with previous CARMENES and HARPS-N observations, we report the nondetection of TiO, Ti I, and V I in the transmission spectrum, while they were already detected in the dayside atmosphere of WASP-33b. This implies a difference in the chemical compositions and abundances between the dayside and terminator atmospheres of WASP-33b and certainly requires further improvements in the sensitivity of the detection methods.

Keywords: exoplanet atmospheres; exoplanet atmospheric composition; transmission spectroscopy; high resolution spectroscopy; hot jupiters; exoplanets; extrasolar gaseous giant planets
Asymmetric H I 21 cm Lines of Fast Radio Burst Hosts: Connection with Galaxy Interaction

Fast radio bursts (FRBs) are enigmatic transients with very short radio emission. Their nature is still widely debated. I provide the first analysis of atomic gas properties of a small sample of FRB hosts to constrain their nature. H I observations exist for NGC 3252, the host of FRB 181030A, M81, the host of FRB 200120E, and the Milky Way, the host of FRB 200428. I report three observables: (i) all three FRB hosts are interacting galaxies; (ii) the H I spectra of both FRB hosts with such data available are highly asymmetric, several standard deviations above the general population of galaxies; (iii) two FRB hosts have normal atomic gas properties and one is strongly deficient in atomic gas. This indicates that nearby and repeating FRBs are connected with a recent enhancement of star formation due to interaction. This supports fast FRB channels, for example, a massive star with a short delay time so that interaction signatures giving rise to the birth of the progenitor are still visible. Long gamma-ray burst (GRB) and broad-lined type Ic supernova (SN) hosts exhibit much more symmetric spectra, even though they were claimed to experience gas inflow from the intergalactic medium. The difference can be explained by the interactions experienced by FRB hosts being more disruptive than these gas inflows, or by the mass effect, with GRB/SN hosts at lower masses having less organized gas motions, so with H I lines closer to a symmetrical Gaussian. This also suggests that the emission mechanisms of FRBs and GRBs are different.

Keywords: spiral galaxies; galaxy groups; interacting galaxies; h i line emission; interstellar atomic gas; gamma-ray bursts; radio transient sources; radio bursts
Observational Quantification of Three-dimensional Anisotropies and Scalings of Space Plasma Turbulence at Kinetic Scales

A statistical survey of spectral anisotropy of space plasma turbulence is performed using five years of measurements from the Magnetospheric Multiscale mission in the magnetosheath. By measuring the five-point second-order structure functions of the magnetic field, we have for the first time quantified the three-dimensional anisotropies and scalings at sub-ion scales (<100 km). In the local reference frame $({\hat{L}}_{\perp },{\hat{l}}_{\perp },{\hat{l}}_{\parallel })$ defined with respect to local mean magnetic field ${{\boldsymbol{B}}}_{0}$ , the "statistical eddies" are found to be mostly elongated along ${{\boldsymbol{B}}}_{0}$ and shortened in the direction perpendicular to both ${{\boldsymbol{B}}}_{0}$ and local field fluctuations. From several di (ion inertial length) toward ∼0.05 di, the ratio between eddies' parallel and perpendicular lengths features a trend of rise then fall, whereas the anisotropy in the perpendicular plane appears scale-invariant. Specifically, the anisotropy relations for the total magnetic field at 0.1-1.0 di are obtained as ${l}_{\parallel }\simeq 2.44\cdot {l}_{\perp }^{0.71}$ , and ${L}_{\perp }\simeq 1.58\cdot {l}_{\perp }^{1.08}$ , respectively. Our results provide new observational evidence to compare with phenomenological models and numerical simulations, which may help to better understand the nature of kinetic-scale turbulence.

Keywords: space plasmas; interplanetary turbulence