bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Timeline of the M81 Group: Properties of the Extended Structures of M82 and NGC 3077
Authors: Velguth Benjamin N. , Bell Eric F. , Smercina Adam , Price Paul , Gozman Katya , Monachesi Antonela , D’Souza Richard , Bailin Jeremy , de Jong Roelof S. , Jang In Sung , Slater Colin T. 
Published: October 2024

Abstract
Mergers of and interactions between galaxies imprint a wide diversity of morphological, dynamical, and chemical characteristics in stellar halos and tidal streams. Measuring these characteristics elucidates aspects of the progenitors of the galaxies we observe today. The M81 group is the perfect galaxy group to understand the past, present, and future of a group of galaxies in the process of merging. Here, we measure the end of star formation (t
90) and metallicity ([M/H]) of the stellar halo of M82 and the eastern tidal stream of NGC 3077 to: (1) test the idea that M82 possesses a genuine stellar halo, formed before any interaction with M81; (2) determine if NGC 3077's tidal disruption is related to the star formation history in its tails; and (3) create a timeline of the assembly history of the central trio in the M81 group. We argue that M82 possesses a genuine, metal-poor ([M/H] ∼ −1.62 dex) stellar halo, formed from the merger of a small satellite galaxy roughly 6.6 Gyr ago. We also find that the stars present in NGC 3077's tails formed before tidal disruption with M81, and possess a roughly uniform metallicity as shown in S. Okamoto et al., implying that NGC 3077's progenitor had significant population gradients. Finally, we present a timeline of the central trio’s merger/interaction history.
Precise and Accurate Short-term Forecasting of Solar Energetic Particle Events with Multivariate Time-series Classifiers
Authors: Rotti Sumanth A. , Aydin Berkay , Martens Petrus C. 
Published: October 2024

Abstract
Solar energetic particle (SEP) events are one of the most crucial aspects of space weather that require continuous monitoring and forecasting using robust methods. We demonstrate a proof of concept of using a data-driven supervised classification framework on a multivariate time-series data set covering solar cycles 22, 23, and 24. We implement ensemble modeling that merges the results from three proton channels (E ≥ 10 MeV, 50 MeV, and 100 MeV) and the long-band X-ray flux (1–8 Å) channel from the Geostationary Operational Environmental Satellite missions. Our task is binary classification, such that the aim of the model is to distinguish strong SEP events from nonevents. Here, strong SEP events are those crossing the Space Weather Prediction Center’s “S1” threshold of solar radiation storm and proton fluxes below that threshold are weak SEP events. In addition, we consider periods of nonoccurrence of SEPs following a flare with magnitudes ≥C6.0 to maintain a natural imbalance of sample distribution. In our data set, there are 244 strong SEP events comprising the positive class. There are 189 weak events and 2460 “SEP-quiet” periods for the negative class. We experiment with summary statistic, one-nearest neighbor, and supervised time-series forest (STSF) classifiers and compare their performance to validate our methods for prediction windows from 5 minutes up to 60 minutes. We find the STSF model to perform better under all circumstances. For an optimal classification threshold of ≈0.3 and a 60 minutes prediction window, we obtain a true skill statistic TSS = 0.850, Heidke skill score HSS = 0.878, and Gilbert skill score GSS = 0.783.
Measuring Dwarf Galaxy Intrinsic Abundance Scatter with Mid-resolution Spectroscopic Surveys: Calibrating APOGEE Abundance Errors
Authors: Mead Jennifer , Ness Melissa , Andersson Eric , Griffith Emily J. , Horta Danny 
Published: October 2024

Abstract
The first generations of stars left their chemical fingerprints on metal-poor stars in the Milky Way and its surrounding dwarf galaxies. While instantaneous and homogeneous enrichment implies that groups of conatal stars should have the same element abundances, small amplitudes of abundance scatter are seen at fixed [Fe/H]. Measurements of intrinsic abundance scatter have been made with small high-resolution spectroscopic data sets where measurement uncertainty is small compared to this scatter. In this work, we present a method to use mid-resolution survey data, which have larger errors, to make this measurement. Using APOGEE Data Release 17, we calculate the intrinsic scatter of Al, O, Mg, Si, Ti, Ni, and Mn relative to Fe for 333 metal-poor stars across six classical dwarf galaxies around the Milky Way, and 1604 stars across 19 globular clusters (GCs). We calibrate the reported abundance errors in bins of signal-to-noise ratio and [Fe/H] using a high-fidelity halo data set. Applying these calibrated errors to the APOGEE data, we find small amplitudes of average intrinsic abundance scatter in dwarf galaxies ranging from 0.03 to 0.09 dex, with a median value of 0.047 dex. For the GCs, we find intrinsic scatters ranging from 0.01 to 0.11 dex, with particularly high scatter for Al and O. Our measurements of intrinsic abundance scatter place important upper bounds, which are limited by our calibration, on the intrinsic scatter in these systems, as well as constraints on their underlying star formation history and mixing that we can look to simulations to interpret.
Balmer Decrement Anomalies in Galaxies at z ∼ 6 Found by JWST Observations: Density-bounded Nebulae or Excited H i Clouds?
Authors: Yanagisawa Hiroto , Ouchi Masami , Nakajima Kimihiko , Yajima Hidenobu , Umeda Hiroya , Baba Shunsuke , Nakagawa Takao , Nakane Minami , Matsumoto Akinori , Ono Yoshiaki , Harikane Yuichi , Isobe Yuki , Xu Yi , Zhang Yechi 
Published: October 2024

Abstract
We investigate the physical origins of the Balmer decrement anomalies in GS-NDG-9422 and RXCJ2248-ID galaxies at z ∼ 6 whose Hα/Hβ values are significantly smaller than 2.7, the latter of which also shows anomalous Hγ/Hβ and Hδ/Hβ values beyond the errors. Because the anomalous Balmer decrements are not reproduced under the Case B recombination, we explore the nebulae with optical depths smaller and larger than the Case B recombination by physical modeling. We find two cases quantitatively explaining the anomalies: (1) density-bounded nebulae that are opaque only up to around Lyγ–Ly8 transitions and (2) ionization-bounded nebulae partly/fully surrounded by optically thick excited H i clouds. The case of (1) produces more Hβ photons via Lyγ absorption in the nebulae, requiring fine tuning in optical depth values, while this case helps ionizing photon escape for cosmic reionization. The case of (2) needs the optically thick excited Hi clouds with N
2 ≃ 1012−1013 cm−2, where N
2 is the column density of the hydrogen atom with the principal quantum number of n = 2. Interestingly, the high N
2 values qualitatively agree with the recent claims for GS-NDG-9422 with the strong nebular continuum requiring a number of 2s-state electrons and for RXCJ2248-ID with the dense ionized regions likely coexisting with the optically thick clouds. While the physical origin of the optically thick excited H i clouds is unclear, these results may suggest gas clouds with excessive collisional excitation caused by an amount of accretion and supernovae in the high-z galaxies.
An Analytic Characterization of the Limb Asymmetry—Transit Time Degeneracy
Authors: Murphy Matthew M. , Beatty Thomas G. , Apai Dániel 
Published: October 2024

Abstract
Atmospheres are not spatially homogeneous. This is particularly true for hot, tidally locked exoplanets with large day-to-night temperature variations, which can yield significant differences between the morning and evening terminators—known as limb asymmetry. Current transit observations with the James Webb Space Telescope (JWST) are precise enough to disentangle the separate contributions of these morning and evening limbs to the overall transmission spectrum in certain circumstances. However, the signature of limb asymmetry in a transit light curve is highly degenerate with uncertainty in the planet’s time of conjunction. This raises the question of how precisely transit times must be measured to enable accurate studies of limb asymmetry, in particular with JWST. Although this degeneracy has been discussed in the literature, a general description of it has not been presented. In this work, we show how this degeneracy results from apparent changes in the transit contact times when the planetary disk has asymmetric limb sizes. We derive a general formula relating the magnitude of limb asymmetry to the amount by which it would cause the apparent time of conjunction to vary, which can reach tens of seconds. Comparing our formula to simulated observations, we find that numerical fitting techniques add additional bias to the measured time, of generally less than a second, resulting from the occultation geometry. We also derive an analytical formula for this extra numerical bias. These formulae can be applied to planning new observations or interpreting literature measurements, and we show examples for commonly studied exoplanets.
Effects of Bursty Star Formation on [C ii] Line Intensity Mapping of High-redshift Galaxies
Authors: Liu Lun-Jun , Sun Guochao , Chang Tzu-Ching , Furlanetto Steven R. , Bradford Charles M. 
Published: October 2024

Abstract
Bursty star formation—a key prediction for high-redshift galaxies from cosmological simulations explicitly resolving stellar feedback in the interstellar medium—has recently been observed to prevail among galaxies at redshift z ≳ 6. Line intensity mapping (LIM) of the 158 μm [C ii] line as a star formation rate (SFR) indicator offers unique opportunities to tomographically constrain cosmic star formation at high redshift, in a way complementary to observations of individually detected galaxies. To understand the effects of bursty star formation on [C ii] LIM, which have remained unexplored in previous studies, we present an analytic modeling framework for high-z galaxy formation and [C ii] LIM signals that accounts for bursty star formation histories induced by delayed supernova feedback. We use it to explore and characterize how bursty star formation can impact and thus complicate the interpretation of the [C ii] luminosity function and power spectrum. Our simple analytic model indicates that bursty star formation mainly affects low-mass galaxies by boosting their average SFR and [C ii] luminosity, and in the [C ii] power spectrum it can create a substantial excess in the large-scale clustering term. This distortion results in a power spectrum shape that cannot be explained by invoking a mass-independent logarithmic scatter. We conclude that burstiness must be accounted for when modeling and analyzing [C ii] data sets from the early Universe, and that in the extreme, the signature of burstiness may be detectable with first-generation experiments such as TIME, CONCERTO, and CCAT-DSS.
Anisotropies of 40–139 keV Ions Measured beyond the Termination Shock and in the Very Local Interstellar Medium
Authors: Dialynas Konstantinos , Krimigis Stamatios M. , Decker Robert B. , Hill Matthew E. , Nikoukar Romina , Opher Merav 
Published: October 2024

Abstract
We analyze the count rates of 40–139 keV ions that were measured in situ by the Low Energy Charged Particle instrument on Voyager 1 in order to identify the suprathermal ion anisotropies beyond the termination shock and in the very local interstellar (IS) medium (VLISM). The analysis results in a region of ∼9–10 au before the heliopause (HP) where the radial anisotropy of ions is negative, while the azimuthal ion anisotropy inside the heliosheath lies in the −T direction. In agreement to our previous analyses, we identify a positive radial anisotropy of ions up to at least ∼30 au beyond the HP, which becomes nearly zero from 2021 up to 2023 November (for ∼10 au). Notably, the anisotropy in the azimuthal direction is statistically zero throughout the upstream region, i.e., for ∼40 au past the HP, showing that the 40–139 keV ion anisotropy in the VLISM is only in the radial direction and has no azimuthal component. The presence of suprathermal ions of solar origin over such long spatial scales in the VLISM, along with the inflow of ions from IS space into the heliosheath, are important constraints for characterizing the interaction of the heliosheath with the VLISM. Our observations provide indications that V1 has entered a new regime in the VLISM since (at least) the year 2021, progressively developing characteristics akin to the pristine IS medium. Alternatively, this drop to nearly zero radial anisotropies beyond 2021 could be a manifestation of a prolonged compression/shock of solar origin.
Hot Stars in the GALEX Ultraviolet Sky Surveys (GUVcat_AISxSDSS_HS) and the Binary Fraction of Hot Evolved Stars
Authors: Bianchi Luciana 
Published: October 2024

Abstract
We present a catalog of 71,364 pointlike UV sources with Sloan Digital Sky Survey (SDSS) photometry and GALEX far-UV (FUV)−near-UV (NUV) ≤0.1 mag. The limit corresponds to stellar T
eff ≳15,000−20,000 K, slightly depending on gravity but nearly reddening independent for Milky Way−type dust. Most sources are hot white dwarfs (WDs) and subdwarfs. Comparing the spectral energy distribution (SED; GALEX FUV, NUV, SDSS u,g,r,i,z) of 35,294 sources having good photometry with colors of stellar models and known objects, we identify 12,404 ±

1267

1871

binary hot-compact stars with a cooler, less-evolved companion (with a possible 8%–15% contamination by low-redshift QSOs), and 22,848 ±

3853

1267

single-star candidates. Single-star counts are an upper limit because pairs of similar stars have single-star-like SEDs, and hot WDs with main-sequence companions of certain types (depending on the WD’s radius) are missed or counted as single in the available wavelength range and selection. The catalog offers unique leverage for identifying hot WDs, elusive at longer wavelengths when a cooler, larger companion dominates optical–IR fluxes: 51% of the binary-star and 20% of the single-star candidates are previously unknown objects. Gaia DR3 provides a parallax with error ≤20% for 34% of the binary-star candidates and 45% of single-star candidates, allowing T
eff, E

B−V
, radius, and L
bol to be derived from SED analysis. The binary-candidate sample usefully expands the overall current binary-WD census to subpopulations elusive to Gaia and to other searches. The binary fraction among this specific sample of hot compact objects, albeit with the mentioned biases, b

f
≳ 46%, compared with that of their progenitors (>80%–50% for mass range 8−1M
⊙, according to M. Moe), implies a lower merging rate than found for massive stars by H. Sana et al.
Impacts of Extreme Ultraviolet Late Phase of the Solar Flare on Ionospheric Electrodynamics
Authors: Liu Xuanqing , Liu Jing , Chen Junjie , Qian Liying , Chamberlin Phillip C. , Chen Yao , Kong Xiangliang , Li Shuhan 
Published: October 2024

Abstract
Previous investigations of ionospheric electrodynamical responses to solar flares primarily focused on the main phases (MPs) of solar flares. Typical solar irradiance models for driving global ionosphere models do not include the extreme ultraviolet (EUV) late phase (ELP) of flares, which was recently observed with new high-quality solar EUV spectra. Thus, it is still unclear how ionospheric electrodynamics respond to the flare ELP. Here, we analyzed the ionospheric electrodynamical response to the MP and ELP of the X9.3 flare on 2017 September 6, using observations from ground magnetometers, along with simulation results from an ionosphere–thermosphere coupled model. Observations indicated an intensification of the dayside eastward equatorial electrojet (EEJ) by approximately 12 nT at the ELP peak as compared to the quiet day reference. Additionally, the dayside eastward electric field increased due to the ELP, which is different from the reduction of dayside electric fields during MP. The upward
E
×
B
plasma drifts decreased by 2.5 m s–1 during MP but increased by 0.75 m s–1 during the ELP. Altitude-dependent responses of ionospheric conductivities to the ELP modulated the relative contribution of the E- and F-region wind dynamo to zonal electric fields, resulting in an overall increase in the daytime eastward electric fields. Furthermore, combined effects of electric fields and conductivities enhancements contributed to EEJ intensification during the ELP. This study enhances our understanding of how solar flares with ELP change global ionospheric electric fields and currents.
A survey of keys for the identification of newly described insect genera: recommendations for authors, reviewers, editors, and publishers
Authors: Packer Laurence 
Published: October 2024

Large numbers of new taxa are described annually and while there is a great need to make them identifiable, there seems little consistency in how this might be facilitated. 427 papers published in 2021 and 2022 were surveyed, which described 587 new insect genera. Only 136 of these papers included keys, and these allowed the identification of 233 of the new genera (31.9% of papers and 39.7% of the new genera). The proportion of papers that included a key varied significantly among insect orders but not among the handful of journals wherein the bulk of the new genera were described. Overall, for 17 key-related variables assessed in a binary fashion (optimal vs suboptimal), the average key had almost six criteria that were scored as being suboptimal. For example, less than one-fifth facilitated retracing and less than 12% had illustrated keys where the images were conveniently located close to the relevant key couplets. Progress towards confirming a putative identification was possible in all papers, through the inclusion of a diagnosis, habitus images, or both.
Based upon this analysis, and expanding on previous suggestions for key construction, 23 recommendations are made on how to make an identification key maximally useful for users and I indicate the relative ease with which each could be adhered to. Identification keys should accompany all new taxon descriptions, guidelines for effective key construction should be added to journals’ instructions to authors, editors and reviewers should check keys carefully, and publishers should be attentive to the needs of users through, for example, permitting duplication of images to make keys easier to use. Recommendations are likely relevant to all levels in the taxonomic hierarchy for all organisms, despite the data being derived from generic-level keys for insects.
Du langage au sauvage : figures animales du plafond peint de Fiches (xviie siècle)
Authors: Leciak Élisabeth 
Published: October 2024

S’intéressant au décor du château de Fiches, un plafond peint du xviie siècle orné de figures animales, cette étude interroge l’instabilité d’un dispositif ornemental et les mutations de sa réception, tant aujourd’hui que par le passé. La découverte des modèles utilisés pour la réalisation du décor ouvre une réflexion sur la fonction attribuée aux images animales, transférées depuis le livre de gravures jusqu’à l’œuvre monumentale via des procédés d’adaptations et de références croisées. L’examen des sources à l’origine des figures révèle de profondes variations entre les différents secteurs du plafond, de l’allégorie au naturalisme, suggérant une réappropriation et une réinterprétation du programme décoratif au cours de l’histoire et montrant, par l’intermédiaire des représentations animales, que le décor est toujours éphémère
La fresque de saint Gilles dans l’église Saint-Nicolas de Civray : image miraculée, image d’un miracle, image miraculeuse ?
Authors: Fabre Pierre-Antoine 
Published: October 2024

On s’intéresse ici à trois moments différents et sédimentés de la légende d’un miracle fondateur, celle de Gilles telle qu’elle apparaît dans l’église abbatiale de Civray en Poitou : la fresque inspirée de cette légende au xiiie siècle, la redécouverte de cette fresque et sa conservation lors de la « restauration » du décor médiéval de l’église au xixe siècle, l’interprétation de cette même fresque dans les premières années du xxie siècle. On s’interroge à travers ces trois moments sur la résistance de ce pan de mur peint, peut-être déjà anachronique dans la conception même de l’agencement de ses surfaces au xiiie siècle.
Allergen sensitization patterns concerning different governorates in Egypt: a retrospective study
Authors: Abdelwahab Heba W. , El-Maksoud Amina A. , Elhosiny Mahmoud M. , Abdalla Dina A. 
Published: October 2024

Background
Allergic disorders afflict 22% of the world’s population. Treatment and prevention of allergic diseases are dependent on correctly identifying the causal allergens and implementing appropriate avoidance approaches. We aimed to assess the variation in patterns of allergen sensitization among patients with allergic disorders in different Egyptian governorates.

Methods
This retrospective study included patients with allergic disorders attending an allergen immunotherapy outpatient clinic. Demographic data, diagnosis of allergic disorders, and skin prick test results of enrolled patients were retrieved from the medical records. Also, patients’ place of residence was recorded by the governorate.

Results
This study included 5024 patients with allergic disorders.
Most of the studied patients were sensitized to mold (94.3%) followed by house dust mites (74.7%) and hay dust (69%). There was no statistical difference in allergen sensitization patterns in different Egyptian governorates. However, there was a statistically significant relation between allergic rhinitis and mixed pollen 1 (P value 0.02) and mite (P value 0.001). For bronchial asthma, both dog hair and chicken feather sensitization patterns showed a strong association with P values 0.02 and 0.03, respectively. Atopic dermatitis had a significant association with both mites (P value 0.001) and barely (P value 0.02).

Conclusion
The sensitization patterns did not significantly differ between the Egyptian governorates. However, it is significantly associated with allergic disorders. The most prevalent sensitization pattern in Egypt was mold.
Assessment of ultrasound-guided tru-cut needle pleural biopsy in the diagnosis of unexplained exudative pleural effusion compared to medical thoracoscopy
Authors: Elaraby Mostafa B. , Elsharkawy Ahmed M. , Attia Ghada A. , Ganna Salwa A. 
Published: October 2024

Background
Ultrasound-guided needle biopsy (USGNB) allows for precise and immediate viewing of pleural lesions, effusions, and needle placement without ionizing radiation. This study aimed to assess the efficacy of US-guided tru-cut needle pleural biopsy in diagnosing unexplained exudative pleural effusion compared to medical thoracoscopy (MT), focusing on safety, accuracy, time, and cost of the treatment.

Patients and methods
This observational cross-sectional research was conducted on 40 patients over 18 years old, of both sexes, with unexplained exudative pleural effusion. The patients were randomly separated into two equal groups. The girst group is USGNB and the second group is MT.

Results
Group II exhibited substantially greater costs, sedation levels, procedure duration, biopsy site discomfort, surgical emphysema, lung expansion failure, and psychological distress compared to group I (P<0.05). There was no notable disparity between the two groups regarding radiological detection of pleural effusion, pleural fluid properties, procedural observations, histological results, and diagnostic effectiveness. The duration of hospitalization was considerably shorter in group I compared to group II, assessed from the day of the operation to the day of release (P=0.001).

Conclusion
USGNB is an important tool in the diagnosis of pleural effusion after failure of pleural fluid analysis, which is performed by a chest physician is an accurate, safer, lower in cost, and shorter in duration with fewer complications compared with MT.