bluuebunny/crossref_metadata_2025_split huggingface dataset:
Astrometric Redshifts of Supernovae
Authors: Lee Jaemyoung (Jason) , Sako Masao , Kessler Richard , Malz Alex I. ,   The LSST Dark Energy Science Collaboration
Published: December 2024

Abstract
Differential Chromatic Refraction (DCR) is caused by the wavelength dependence of our atmosphere’s refractive index, which shifts the apparent positions of stars and galaxies and distorts their shapes depending on their spectral energy distributions. While this effect is typically mitigated and corrected for in imaging observations, we investigate how DCR can instead be used to our advantage to infer the redshifts of supernovae from multiband, time-series imaging data. We simulate Type Ia supernovae in the proposed Vera C. Rubin Observatory Legacy Survey of Space and Time Deep Drilling Field, and evaluate astrometric redshifts. We find that the redshift accuracy improves dramatically with the statistical quality of the astrometric measurements as well as with the accuracy of the astrometric solution. For a conservative choice of a 5 mas systematic uncertainty floor, we find that our redshift estimation is accurate at z < 0.6. We then combine our astrometric redshifts with both host-galaxy photometric redshifts and supernovae photometric (light-curve) redshifts and show that this considerably improves the overall redshift estimates. These astrometric redshifts will be valuable, especially since Rubin will discover a vast number of supernovae for which we will not be able to obtain spectroscopic redshifts.
GRB 211024B: An Ultra-long GRB Powered by Magnetar
Authors: Fu Shao-Yu , Xu Dong , Lei Wei-Hua , de Ugarte Postigo Antonio , Malesani Daniele B. , Kann David Alexander , Jakobsson Páll , Fynbo Johan P. U. , Maiorano Elisabetta , Rossi Andrea , Paris Diego , Liu Xing , Jiang Shuai-Qing , Lu Tian-Hua , An Jie , Zhu Zi-Pei , Gao Xing , Wei Jian-Yan 
Published: December 2024

Abstract
Ultra-long gamma-ray bursts are characterized by exceptionally long-duration central engine activities, with characteristic timescales exceeding 1000 s. We present ground-based optical afterglow observations of the ultra-long gamma-ray burst GRB 211024B, detected by Swift. Its X-ray light curve exhibits a characteristic “internal plateau” with a shallow decay phase lasting approximately ∼15 ks, followed by a steep decline (α
drop ∼ −7.5). Moreover, the early optical emission predicted by the late r-band optical afterglow is significantly higher than the observed value, indicating an external shock with energy injection. To explain these observations, we propose a magnetar central engine model. The magnetar collapses into a black hole due to spin-down or hyperaccretion, leading to the observed steep break in the X-ray light curve. The afterglow model fitting reveals that the afterglow injection luminosity varies with different assumptions of the circumburst medium density, implying different potential energy sources. For the interstellar medium case with a fixed injection end time, the energy may originate from the magnetar’s dipole radiation. However, in other scenarios, relativistic jets produced by the magnetar/black hole system could be the primary energy source.
Realistic Outcomes of Moon–Moon Collisions in Lunar Formation Theory
Authors: Malamud Uri , Perets Hagai B. 
Published: December 2024

Abstract
The multiple impact hypothesis proposes that the Moon formed through a series of smaller collisions, rather than a single giant impact. This study advances our understanding of this hypothesis, as well as moon collisions in other contexts, by exploring the implications of these smaller impacts, employing a novel methodological approach that combines self-consistent initial conditions, hybrid hydrodynamic/N-body simulations, and the incorporation of material strength. Our findings challenge the conventional assumption of perfect mergers in previous models, revealing a spectrum of collision outcomes including partial accretion and mass loss. These outcomes are sensitive to collision parameters and the Earth’s tidal influence, underscoring the complex dynamics of lunar accretion. Importantly, we demonstrate that incorporating material strength is important for accurately simulating moonlet-sized impacts. This inclusion significantly affects fragmentation, tidal disruption, and the amount of material ejected or accreted onto the Earth, ultimately impacting the Moon’s growth trajectory. By accurately modeling diverse collision outcomes, our hybrid approach provides a powerful new framework for understanding the Moon’s formation. We show that most collisions (≈90%) do not significantly erode the largest moonlet, supporting the feasibility of lunar growth through accretion. Moreover, we revise previous estimates of satellite disruption, suggesting a higher survival rate and further bolstering the multiple-impact scenario.
Investigating Differences in the Palomar-Green Blazar Population Using Polarization
Authors: Baghel Janhavi , Kharb P. , Hovatta T. , Ho Luis C. , Harrison C. , Lindfors E. , S. Silpa , Gulati S. 
Published: December 2024

Abstract
We present polarization images with the Karl G. Jansky Very Large Array (VLA) in A- and B-array configurations at 6 GHz of seven radio-loud (RL) quasars and eight BL Lac objects belonging to the Palomar-Green (PG) “blazar” sample. This completes our arcsecond-scale polarization study of an optically selected volume-limited blazar sample comprising 16 radio-loud quasars and 8 BL Lac objects. Using the VLA, we identify kiloparsec-scale polarization in the cores and jets/lobes of all the blazars, with fractional polarization varying from around 0.8% ± 0.3% to 37% ± 6%. The kiloparsec-scale jets in PG RL quasars are typically aligned along their parsec-scale jets and show apparent magnetic fields parallel to jet directions in their jets/cores and magnetic field compression in their hot spots. The quasars show evidence of interaction with their environment as well as restarted active galactic nucleus activity through morphology, polarization, and spectral indices. These quasi-periodic jet modulations and restarted activity may be indicative of an unstable accretion disk undergoing transition. We find that the polarization characteristics of the BL Lacs are consistent with their jets being reoriented multiple times, with no correlation between their core apparent magnetic field orientations and parsec-scale jet directions. We find that the low synchrotron peaked BL Lacs show polarization and radio morphology features typical of “strong” jet sources as defined by E. T. Meyer et al. for the “blazar envelope scenario,” which posits a division based on jet profiles and velocity gradients rather than total jet power.
Constraining the Excitation of Molecular Gas in Two Quasar-starburst Systems at z ∼ 6
Authors: Xu Fuxiang , Wang Ran , Li Jianan , Neri Roberto , Pensabene Antonio , Decarli Roberto , Shao Yali , Bañados Eduardo , Cox Pierre , Bertoldi Frank , Feruglio Chiara , Walter Fabian , Venemans Bram P. , Omont Alain , Riechers Dominik , Wagg Jeff , Menten Karl M. , Fan Xiaohui 
Published: December 2024

Abstract
We present NOrthern Extended Millimeter Array observations of CO(8–7), (9–8), and (10–9) lines, as well as the underlying continuum for two far-infrared luminous quasars: SDSS J2054-0005 at z = 6.0389 and SDSS J0129-0035 at z = 5.7788. Both quasars were previously detected in CO (2–1) and (6–5) transitions, making them candidates for studying the CO spectral line energy distribution (SLED) of quasars at z ∼ 6. Utilizing the radiative transfer code CLOUDY, we fit the CO SLED with two heating mechanisms, including the photodissociation region (PDR) and X-ray-dominated region (XDR) for both objects. The CO SLEDs can be fitted by either a dense PDR component with an extremely strong far-ultraviolet radiation field (gas density n
H ∼ 106 cm−3 and field strength G
0 ≳ 106) or a two-component model including a PDR and an XDR. However, the line ratios, including L
TIR and previous [C ii]158 μm and [C i]369 μm measurements, argue against a very high PDR radiation field strength. Thus, the results prefer a PDR+XDR origin for the CO SLED. The excitation of the high-J CO lines in both objects is likely dominated by the central active galactic nucleus (AGN). We then check the CO (9–8)-to-(6–5) line luminosity ratio r
96 for all z ∼ 6 quasars with available CO SLEDs (seven in total) and find that there are no clear correlations between r
96 and both L
FIR and the AGN UV luminosities. This further demonstrates the complexity of the CO excitation powered by both the AGN and nuclear star formation in these young quasar host galaxies.
Photochemical Hazes in Exoplanetary Skies with Diamonds: Microphysical Modeling of Haze Composition Evolution via Chemical Vapor Deposition
Authors: Ohno Kazumasa 
Published: December 2024

Abstract
Observational efforts in the last decade suggest the prevalence of photochemical hazes in exoplanetary atmospheres. Recent JWST observations raise growing evidence that exoplanetary hazes tend to have reflective compositions, unlike the conventionally assumed haze analogs, such as tholin and soot. In this study, I propose a novel hypothesis: diamond formation through chemical vapor deposition (CVD) may be happening in exoplanetary atmospheres. Using an aerosol microphysical model combined with the theory of CVD diamond and soot formation established in the industry community, I study how the haze composition evolves in exoplanetary atmospheres for various planetary equilibrium temperatures, atmospheric metallicity, and C/O ratio. I find that CVD diamond growth dominates over soot growth in a wide range of planetary parameters. Diamond haze formation is most efficient at T
eq ∼ 1000 K and low atmospheric metallicity ([M/H] ≤ 2.0), while soot could be the main haze component only if the atmosphere is hot (T
eq ≳ 1200 K) and carbon rich (C/O > 1). I also compute transmission, emission, and reflected light spectra, thereby suggesting possible observational signatures of diamond hazes, including the 3.53 μm feature of hydrogenated diamonds, anomalously faint thermal emission due to thermal scattering, and a drastic increase in geometric albedo. This study suggests that warm exoplanetary atmospheres may be favorable sites for forming CVD diamonds, which would be testable by future observations by JWST and Ariel as well as haze synthesis experiments under hot hydrogen-rich conditions.
Theoretical Diagnostics for Narrow-line Regions of Active Galactic Nuclei
Authors: Zhu Peixin , Kewley Lisa J. , Sutherland Ralph S. 
Published: December 2024

Abstract
Gas metallicity, ionization parameter, and gas pressure can affect the observed ratios of specific strong emission lines within galaxies. While the theoretical strong lines diagnostics for gas metallicity, ionization parameters, and gas pressure in star-forming regions are well-established, theoretical diagnostics for active galactic nuclei (AGNs) narrow-line regions are still lacking. In P. Zhu et al., we presented a new AGN model that provides the best predictions for observations spanning the UV, optical, and infrared wavelengths. This paper presents a suite of theoretical diagnostics for the gas metallicity, ionization parameter, gas pressure, and the peak energy in AGN ionizing radiation field E
peak for AGN narrow-line regions spanning the UV and optical wavelengths. We investigate the model dependency on the ionization parameter, gas pressure, E
peak, and the nitrogen scaling relation and make recommendations on metallicity diagnostics that are most robust against these parameters. We test our new AGN metallicity diagnostics using optical galaxy spectra from Sloan Digital Sky Survey DR16. These tests show that the metallicities measured from different diagnostics in this paper are consistent within ∼0.3 dex. We compare consistent H ii and AGN diagnostics and demonstrate that H ii and AGN diagnostics should not be used interchangeably. With a wide wavelength coverage, we anticipate that these AGN diagnostics will enable new metallicity studies of galaxies dominated by AGN.
Visual Orbits of Wolf–Rayet Stars. II. The Orbit of the Nitrogen-rich Wolf–Rayet Binary WR 138 Measured with the CHARA Array
Authors: Holdsworth Amanda , Richardson Noel , Schaefer Gail H. , Eldridge Jan J. , Hill Grant M. , Spejcher Becca , Mackey Jonathan , Moffat Anthony F. J. , Navarete Felipe , Monnier John D. , Kraus Stefan , Le Bouquin Jean-Baptiste , Anugu Narsireddy , Chhabra Sorabh , Codron Isabelle , Ennis Jacob , Gardner Tyler , Gutierrez Mayra , Ibrahim Noura , Labdon Aaron , Lanthermann Cyprien , Setterholm Benjamin R. 
Published: December 2024

Abstract
Classical Wolf–Rayet (WR) stars are descendants of massive OB-type stars that have lost their hydrogen-rich envelopes and are in the final stages of stellar evolution, possibly exploding as Type Ib/c supernovae. It is understood that the mechanisms driving this mass loss are either strong stellar winds and or binary interactions, so intense studies of these binaries including their evolution can tell us about the importance of the two pathways in WR formation. WR 138 (HD 193077) has a period of just over 4 yr and was previously reported to be resolved through interferometry. We report on new interferometric data combined with spectroscopic radial velocities in order to provide a three-dimensional orbit of the system. The precision on our parameters tend to be about an order of magnitude better than previous spectroscopic techniques. These measurements provide masses of the stars, namely, M
WR = 13.93 ± 1.49 M
⊙ and M
O = 26.28 ± 1.71 M
⊙. The derived orbital parallax agrees with the parallax from Gaia, namely, with a distance of 2.13 kpc. We compare the system’s orbit to models from BPASS, showing that the system likely may have been formed with little interaction but could have formed through some binary interactions either following or at the start of a red supergiant phase but with the most likely scenario occurring as the red supergiant phase starts for a ∼40 M
⊙ star.
Prediction of Large Solar Flares Based on SHARP and High-energy-density Magnetic Field Parameters
Authors: Li Xuebao , Li Xuefeng , Zheng Yanfang , Li Ting , Yan Pengchao , Ye Hongwei , Zhang Shunhuang , Wang Xiaotian , Lv Yongshang , Huang Xusheng 
Published: December 2024

Abstract
The existing flare prediction primarily relies on photospheric magnetic field parameters from the entire active region (AR), such as Space-Weather HMI Activity Region Patches (SHARP) parameters. However, these parameters may not capture the details of the AR evolution preceding flares. The magnetic structure within the core area of an AR is essential for predicting large solar flares. This paper utilizes the area of high photospheric free energy density (high-energy-density, hereafter HED, region) as a proxy for the AR core region. We construct two data sets: SHARP and HED data sets. The ARs contained in both data sets are identical. Furthermore, the start and end times for the same AR in both data sets are identical. We develop six models for 24 hr solar flare forecasting, utilizing SHARP and HED data sets. We then compare their categorical and probabilistic forecasting performance. Additionally, we conduct an analysis of parameter importance. The main results are as follows: (1) Among the six solar flare prediction models, the models using HED parameters outperform those using SHARP parameters in both categorical and probabilistic prediction, indicating the important role of the HED region in the flare initiation process. (2) The transformer flare prediction model stands out significantly in true skill statistic and Brier skill score, surpassing the other models. (3) In parameter importance analysis, the total photospheric free magnetic energy density (E
free) within the HED parameters excels in both categorical and probabilistic forecasting. Similarly, among the SHARP parameters, the R_VALUE stands out as the most effective parameter for both categorical and probabilistic forecasting.
Data-space Validation of High-dimensional Models by Comparing Sample Quantiles
Authors: Thorp Stephen , Peiris Hiranya V. , Mortlock Daniel J. , Alsing Justin , Leistedt Boris , Deger Sinan 
Published: December 2024

Abstract
We present a simple method for assessing the predictive performance of high-dimensional models directly in data space when only samples are available. Our approach is to compare the quantiles of observables predicted by a model to those of the observables themselves. In cases where the dimensionality of the observables is large (e.g., multiband galaxy photometry), we advocate that the comparison is made after projection onto a set of principal axes to reduce the dimensionality. We demonstrate our method on a series of two-dimensional examples. We then apply it to results from a state-of-the-art generative model for galaxy photometry (pop-cosmos) that generates predictions of colors and magnitudes by forward simulating from a 16-dimensional distribution of physical parameters represented by a score-based diffusion model. We validate the predictive performance of this model directly in a space of nine broadband colors. Although motivated by this specific example, we expect that the techniques we present will be broadly useful for evaluating the performance of flexible, nonparametric population models of this kind, and other settings where two sets of samples are to be compared.
Astronomical Pointlike Source Detection via Deep Feature Matching
Authors: Long Ma , Jiarong Xin , Jiangbin Du , Jiayao Zhao , Xiaotian Wang , Yu Zhang 
Published: December 2024

Abstract
This study introduces PSDetNet, an innovative deep neural network tailored for the autonomous detection of pointlike astronomical sources by leveraging feature-matching techniques. PSDetNet comprises two primary modules: feature extraction and matching localization. The feature extraction module is built on residual blocks and adopts an encoder–decoder framework to distill features from images robustly. The matching localization module employs a patch-by-patch comparison against a preconstructed template, which is crafted through the alignment and weighted aggregation of numerous exemplar pointlike source samples, capturing the quintessential distribution characteristics of pointlike sources. The experimental results demonstrate that this network can accurately detect pointlike sources in astronomical imagery with high purity and completeness. It operates end to end and uses a fully convolutional architecture that allows for flexible processing of images of any size. This ability considerably enhances its applicability across various practical scenarios.
A New View of the Spiral Structure of the Northern Outer Milky Way in Carbon Monoxide
Authors: Sun Yan , Yang Ji , Zhang Shaobo , Yan Qing-Zeng , Su Yang , Chen Xuepeng , Zhou Xin , Xu Ye , Wang Hongchi , Wang Min , Jiang Zhibo , Sun Ji-Xian , Lu Deng-Rong , Ju Bing-Gang , Zhang Xu-Guo , Wang Min 
Published: December 2024

Abstract
Based on 32,162 molecular clouds from the Milky Way Imaging Scroll Painting project, we obtain new face-on molecular gas maps of the northern outer Galaxy. The total molecular gas surface density map reveals three segments of spirals, extending 16–43 kpc in length. The Perseus and Outer arms stand out prominently, appearing as quasi-continuous structures along most of their length. At the Galactic outskirts, about 1306 clouds connect the two segments of the new spiral arm discovered by T. M. Dame & P. Thaddeus (2011) in the first quadrant and Y. Sun et al. in the second quadrant, possibly extending the arm into the outer third quadrant. Logarithmic spirals can be fitted to the CO arm segments with pitch angles ranging from 4∘ to 12∘. These CO arms extend beyond previous CO studies and the optical radius, reaching a Galactic radius of about 22 kpc, comparable to the H i radial range.
Detailed Study of Stars and Gas in a z = 8.3 Massive Merger with Extreme Dust Conditions
Authors: Harshan Anishya , Tripodi Roberta , Martis Nicholas S. , Rihtaršič Gregor , Bradač Maruša , Asada Yoshihisa , Brammer Gabe , Desprez Guillaume , Estrada-Carpenter Vince , Matharu Jasleen , Markov Vladan , Muzzin Adam , Mowla Lamiya , Noirot Gaël , Sarrouh Ghassan T. E. , Sawicki Marcin , Strait Victoria , Willott Chris 
Published: December 2024

Abstract
We present galaxy MACS0416-Y1 at z
spec = 8.312 as observed by the CAnadian NIRISS Unbiased Cluster Survey. MACS0416-Y1 has been shown to have extreme dust properties; thus, we study the physical properties and star formation histories of its resolved components. Overall, we find that MACS0416-Y1 is undergoing a star formation burst in three resolved clumps. The central clump is less massive compared to the other clumps and possibly formed in the merging process of the two larger clumps. Although the star formation history indicates an ongoing star formation burst, this gas-rich galaxy shows comparable star formation efficiency to cosmic noon galaxies. Using NIRSpec prism spectroscopy, we measure metallicity,

12
+
log
(O/H)
=
7.76
±
0.03

, ionization parameter,

log
U
=
−
2.48
±
0.03

, and electron temperature T

e
= 18000 ± 4000 K. The emission line ratios of the galaxy indicate an evolved interstellar medium similar to z ∼ 2 star-forming galaxies. Further, we find possible presence of ionization from an active galactic nucleus (AGN) using emission line diagnostics; however, we do not detect a broad-line component in the Hβ emission line. As this gas-rich galaxy is undergoing a major merger, we hypothesize that the high dust temperature in MACS0416-Y1 is caused by the star formation burst or a possible narrow-line AGN.
Determination of the Abundance of Mercury from the Hg ii Line at 5677.10 Å in Late B-type Stars. XI. HD 11753 (ϕ Phe)
Authors: Monier Richard 
Published: December 2024

Abstract
The weak line of Hg ii located at 5677.10 Å is not detected in a coadded HARPS spectrum of the HgMn star HD 11753 which may be explained by the moderate excess of mercury in this star compared to other HgMn stars. The synthesis of the 4400–4600 Å spectral range yields several new measurements of the abundances of helium, magnesium, aluminum, silicon, titanium, chromium, manganese, iron, nickel and platinum. These new measurements agree well with previous measurements. The synthesis of the Pt ii line at 4514.14 Å, yields a first measurement of a large excess of platinum (+3.74 dex) in HD 11753.
Towards distant seas and lands
Authors: Masseti Marco 
Published: December 2024

There is considerable archaeological evidence for the circulation and trade of materials, ideas and living beings between the Mediterranean, the Near and the Middle East during the 1st millennium BC. A similar phenomenon has also affected the displacement of various faunal elements that have been exported to new territories completely unrelated to the natural environment of their homelands. Unfortunately, regarding the export of some of them cultural models based on little, if any, scientific evidence still persists.
Involuntary introductions in the Ancient Mediterranean
Authors: Lewis Sian 
Published: December 2024

This article considers the movements of animal species in Antiquity which took place without intentional human intervention. After establishing the context of limited human control over the many species which exploited the towns and settlements I focus on two groups of animals, rodents and insects. Both the house mouse (Mus musculus) and the black rat (Rattus rattus) were accidentally introduced to the Western Mediterranean, the former as a result of Phoenician and Greek maritime trade in the Iron Age and the black rat as a consequence of trade from Egypt under the Roman Empire, while two of the most damaging grain pests in antiquity, the saw-toothed grain beetle (Oryzaephilus surinamensis) and the grain weevil (Sitophilus granarius), were similarly unwittingly introduced to the Mediterranean and Europe via the movement of infested grain at the end of the 1st millennium BC. These movements offer a salutary reminder that ancient humans were not masters of the zoosphere which they inhabited, but merely one component part of a complex web of relationships.