bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long Plateau Doth So: How Internal Heating Sources Affect Hydrogen-rich Supernova Light Curves
Authors: Matsumoto Tatsuya , Metzger Brian D. , Goldberg Jared A. 
Published: December 2024

Abstract
Some hydrogen-rich core-collapse supernovae (SNeIIP) exhibit evidence of a sustained energy source powering their light curves, resulting in a brighter and/or longer-lasting hydrogen recombination plateau phase. We present a semi-analytic SNIIP light-curve model that accounts for the effects of an arbitrary internal heating source, considering as special cases 56Ni/56Co decay, a central engine (magnetar or accreting compact object), and shock interaction with a dense circumstellar disk. While a sustained internal power source can boost the plateau luminosity commensurate with the magnitude of the power, the duration of the recombination plateau can typically be increased by at most a factor of ∼2–3 compared to the zero-heating case. For a given ejecta mass and initial kinetic energy, the longest plateau duration is achieved for a constant heating rate at the highest magnitude that does not appreciably accelerate the ejecta. This finding has implications for the minimum ejecta mass required to explain particularly long-lasting SNe, such as iPTF14hls, and for confidently identifying rare explosions of the most massive hydrogen-rich (e.g., Population III) stars. We present a number of analytic estimates that elucidate the key features of the detailed model.
Precise Measurements of the LMC Bar’s Geometry with Gaia DR3 and a Novel Solution to Crowding-induced Incompleteness in Star Counting
Authors: Rathore Himansh , Choi Yumi , Olsen Knut A. G. , Besla Gurtina 
Published: December 2024

Abstract
We present new measurements of the 2D geometry of the LMC’s stellar bar with precise astrometric observations of red clump stars in Gaia DR3. We develop a novel solution to tackle crowding-induced incompleteness in Gaia data sets with the Gaia BP-RP color excess. Utilizing the color excess information, we derive a 2D completeness map of the LMC’s disk. We find that incompleteness biases the bar measurements and induces large uncertainties. With the completeness-corrected 2D red clump map, we precisely measure the LMC bar’s properties using Fourier decomposition. The bar radius (semimajor axis) is

R

bar

=

2.13

−
0.04

+
0.03

kpc, and its position angle is 121.°26 ± 0.°21. The bar’s strength as quantified by the Fourier bi-symmetric amplitude is S
bar = 0.27, indicating that the LMC has a significant bar perturbation. We find the bar has an axis ratio of 0.54 ± 0.03, and is offset with respect to the center of the outer disk isophote at R ≈ 5 kpc by 0.76 ± 0.01 kpc. These LMC bar properties agree with a hydrodynamic model where the SMC has undergone a recent direct collision with the LMC. We compare the LMC’s bar properties with other barred galaxies in the local Universe, and discover that the LMC is similar to other barred galaxies in terms of bar-galaxy scaling relations. We discuss how our completeness correction framework can be applied to other systems in the Local Group.
Radial Velocity and Astrometric Evidence for a Close Companion to Betelgeuse
Authors: MacLeod Morgan , Blunt Sarah , De Rosa Robert J. , Dupree Andrea K. , Granzer Thomas , Harper Graham M. , Huang Caroline D. , Leiner Emily M. , Loeb Abraham , Nielsen Eric L. , Strassmeier Klaus G. , Wang Jason J. , Weber Michael 
Published: December 2024

Abstract
We examine a century of radial velocity, visual magnitude, and astrometric observations of the nearest red supergiant, Betelgeuse, in order to reexamine the century-old assertion that Betelgeuse might be a spectroscopic binary. These data reveal Betelgeuse varying stochastically over years and decades due to its boiling, convective envelope, periodically with a 5.78 yr long secondary period (LSP), and quasiperiodically from pulsations with periods of several hundred days. We show that the LSP is consistent between astrometric and radial velocity data sets, and argue that it indicates a low-mass companion to Betelgeuse, less than a solar mass, orbiting in a 2110 day period at a separation of just over twice Betelgeuse’s radius. The companion star would be nearly 20 times less massive and a million times fainter than Betelgeuse, with similar effective temperature, effectively hiding it in plain sight near one of the best-studied stars in the night sky. The astrometric data favor an edge-on binary with orbital plane aligned with Betelgeuse’s measured spin axis. Tidal spin–orbit interaction drains angular momentum from the orbit and spins up Betelgeuse, explaining the spin–orbit alignment and Betelgeuse’s anomalously rapid spin. In the future, the orbit will decay until the companion is swallowed by Betelgeuse in the next 10,000 yr.
Spectral Energy Distribution Modeling of BL Lacertae during a Large Submillimeter Outburst and Low X-Ray Polarization State
Authors: Mondal Ayon , Sar Arijit , Kundu Maitreya , Chatterjee Ritaban , Majumdar Pratik 
Published: December 2024

Abstract
In 2023 October–November, the blazar BL Lacertae underwent a very large-amplitude submillimeter outburst. The usual single-zone leptonic model with the lower-energy peak of the spectral energy distribution (SED) fit by the synchrotron emission from one distribution of relativistic electrons in the jet and inverse-Compton (IC) scattering of lower-energy photons from the synchrotron radiation in the jet itself (synchrotron self-Compton or SSC) or those from the broad-line region and torus by the same distribution of electrons cannot satisfactorily fit the broadband SED with simultaneous data at submillimeter, optical, X-ray, and GeV energies. Furthermore, simultaneous observations with IXPE indicate the X-ray polarization is undetected. We consider two different synchrotron components, one for the high flux in the submillimeter wavelengths and another for the data at the optical band, which are supposedly due to two separate distributions of electrons. In that case, the optical emission is dominated by the synchrotron radiation from one electron distribution, while the X-rays are mostly due to SSC process by another, which may result in low polarization fraction due to the IC scattering. We show that such a model can fit the broadband SED satisfactorily as well as explain the low polarization fraction at the X-rays.
Chemical Links between a Young M-type T Tauri Star and Its Substellar Companion: Spectral Analysis and C/O Measurement of DH Tau A
Authors: Hejazi Neda , Xuan Jerry W. , Coria David R. , Sawczynec Erica , Crossfield Ian J. M. , Cristofari Paul I. , Zhang Zhoujian , Rhem Maleah 
Published: December 2024

Abstract
The chemical abundance measurements of host stars and their substellar companions provide a powerful tool to trace the formation mechanism of the planetary systems. We present a detailed high-resolution spectroscopic analysis of a young M-type star, DH Tau A, which is located in the Taurus molecular cloud belonging to the Taurus-Auriga star-forming region. This star is host to a low-mass companion, DH Tau b, and both the star and the companion are still in their accreting phase. We apply our technique to measure the abundances of carbon and oxygen using carbon- and oxygen-bearing molecules, such as CO and OH, respectively. We determine a near-solar carbon-to-oxygen abundance ratio of C/O = 0.555 ± 0.063 for the host star DH Tau A. We compare this stellar abundance ratio with that of the companion from our previous study (

C

/

O
=

0.54

−
0.05

+
0.06

), which also has a near-solar value. This confirms the chemical homogeneity in the DH Tau system, which suggests a formation scenario for the companion consistent with a direct and relatively fast gravitational collapse rather than a slow core accretion process.
Analysis of Solar Eruptions Deflecting in the Low Corona: Influence of the Magnetic Environment
Authors: Sahade Abril , Vourlidas Angelos , Mac Cormack Cecilia 
Published: December 2024

Abstract
Coronal mass ejections (CMEs) can exhibit nonradial evolution. The background magnetic field is considered the main driver for the trajectory deviation relative to the source region. The influence of the magnetic environment has been largely attributed to the gradient of the magnetic pressure. In this work, we propose a new approach for investigating the role of topology on CME deflection and for quantifying and comparing the action between the magnetic field gradient (“gradient” path) and the topology (“topological” path). We investigate eight events simultaneously observed by the Solar Orbiter, STEREO-A, and the Solar Dynamics Observatory; and, with a new tracking technique, we reconstruct the 3D evolution of the eruptions. Then, we compare their propagation with the predictions from the two magnetic drivers. We find that the “topological” path describes the CME actual trajectory much better than the more traditional “gradient path.” Our results strongly indicate that the ambient topology may be the dominant driver for deflections in the low corona, and that this presents a promising method for estimating the direction of propagation of CMEs early in their evolution.
Microlensing Discovery and Characterization Efficiency in the Vera C. Rubin Legacy Survey of Space and Time
Authors: Abrams Natasha S. , Hundertmark Markus P. G. , Khakpash Somayeh , Street Rachel A. , Jones R. Lynne , Lu Jessica R. , Bachelet Etienne , Tsapras Yiannis , Moniez Marc , Blaineau Tristan , Di Stefano Rosanne , Makler Martin , Varela Anibal , Rabus Markus 
Published: December 2024

Abstract
The Vera C. Rubin Legacy Survey of Space and Time will discover thousands of microlensing events across the Milky Way, allowing for the study of populations of exoplanets, stars, and compact objects. We evaluate numerous survey strategies simulated in the Rubin Operation Simulations to assess the discovery and characterization efficiencies of microlensing events. We have implemented three metrics in the Rubin Metric Analysis Framework: a discovery metric and two characterization metrics, where one estimates how well the light curve is covered and the other quantifies how precisely event parameters can be determined. We also assess the characterizability of microlensing parallax, critical for detection of free-floating black hole lenses. We find that, given Rubin’s baseline cadence, the discovery and characterization efficiency will be higher for longer-duration and larger-parallax events. Microlensing discovery efficiency is dominated by the observing footprint, where more time spent looking at regions of high stellar density, including the Galactic bulge, Galactic plane, and Magellanic Clouds, leads to higher discovery and characterization rates. However, if the observations are stretched over too wide an area, including low-priority areas of the Galactic plane with fewer stars and higher extinction, event characterization suffers by >10%. This could impact exoplanet, binary star, and compact object events alike. We find that some rolling strategies (where Rubin focuses on a fraction of the sky in alternating years) in the Galactic bulge can lead to a 15%–20% decrease in microlensing parallax characterization, so rolling strategies should be chosen carefully to minimize losses.
Time-averaging Polarimetric and Spectral Properties of Gamma-Ray Bursts
Authors: Li Liang , Shakeri Soroush 
Published: December 2024

Abstract
The composition and radiation mechanism of gamma-ray bursts (GRBs) within jets continue to be hotly debated. Investigating the joint polarimetric and spectral properties is crucial for understanding the composition and radiation mechanism of GRBs. Various jet properties, such as “kinetic-energy-dominated” (KED), “Poynting-flux-dominated” (PFD), and “hybrid-dominated” (HD) relativistic outflows, have been inferred from observed GRB spectra, with expectations of differing polarization levels among them. In this study, we analyzed a sample of 27 GRBs detected by the Gamma-ray Burst Monitor on board the NASA Fermi Gamma-ray Space Telescope, focusing on 26 bursts with significant polarization measurements. Our analysis revealed that 16 bursts (62%) were predominantly associated with the “PFD” jet type, while 10 bursts (38%) were classified as HD, implying that photosphere emission may also be a possible mechanism powering the high levels of polarization. Notably, no bursts were identified as KED type. We found distinct polarization properties, with HD-type bursts exhibiting consistently higher polarization levels than PFD-type bursts. We proposed models incorporating ordered and random magnetic field configurations specific to hybrid jets.
Measuring the Hubble Constant through the Galaxy Pairwise Peculiar Velocity
Authors: Zhang Wangzheng , Chu Ming-chung , Liao Shihong , Yeung Shek , Hu Hui-Jie 
Published: December 2024

Abstract
The Hubble constant H
0, the current expansion rate of the Universe, is one of the most important parameters in cosmology. The cosmic expansion regulates the mutually approaching motion of a pair of celestial objects due to their gravity. Therefore, the mean pairwise peculiar velocity of celestial objects, which quantifies their relative motion, is sensitive to both H
0 and the dimensionless total matter density Ω
m
. Based on this, using the Cosmicflows-4 data, we measured H
0 for the first time via the galaxy pairwise velocity in the nonlinear and quasi-linear range. Our results yield H
0 = 75.5 ± 1.4 km s−1 Mpc−1 and

Ω

m

=
0.31

1

−
0.028

+
0.029

. The uncertainties of H
0 and Ω
m
can be improved to around 0.6% and 2%, respectively, if the statistical errors become negligible in the future.
L’origine des oiseaux, hier et aujourd’hui : petit retour historique sur un changement de paradigme
Authors: de Ricqlès Armand 
Published: December 2024

Le vieux problème de l’origine évolutive des oiseaux peut être désormais considéré comme résolu. Cet article passe brièvement en revue le cheminement historique complexe, encombré de contraintes diverses, qui a été parcouru et comment il a conduit à diverses hypothèses qui ont pu être testées par des découvertes ultérieures. Bien qu’une relation de parenté entre Reptiles et Oiseaux ait été reconnue dès le XIX e siècle grâce à l’anatomie comparée, la nature de ces relations est demeurée assez confuse pendant les deux premiers tiers du XX e siècle, au moins. La toute-puissance du concept Linnéen des grandes Classes de vertébrés a jugulé les esprits de telle sorte qu’en dépit de la description d’ Archaeopteryx à partir de 1859 ce fossile a été le plus souvent considéré comme un « missing link » entre Classes, moitié reptile, moitié oiseau. Le développement de la connaissance des Dinosaures dès les années 1860-1870 avait bien suggéré qu’ils étaient, parmi les reptiles, les plus étroitement apparentés aux oiseaux mais cette idée fut largement abandonnée à partir des années 1920. Le changement complet d’interprétation sur cette question, intervenu à partir des années 1970 ne résulte pas, curieusement, de nouvelles découvertes sur le terrain (celles-ci ne sont venues qu’après !) mais bien d’une remise en cause radicale des principes et modes de pensée de la systématique, intervenue avec l’analyse phylogénétique (cladistique). À l’heure actuelle, il est clair que les oiseaux sont un groupe de dinosaures théropodes modifiés par diverses adaptations dont celle au vol. On passera brièvement en revue diverses étapes et composantes intervenues dans ce changement de paradigmes.
Efficacy of early enteral feeding with supplemented mother’s milk on postoperative outcomes of cardiac surgical infants: A randomized controlled trial
Authors: Singal Anuradha , Sahu Manoj Kumar , Kumar Geeta Trilok , Aeri Bani Tamber , Manral Mala , Agarwala Anuja , Pandey Shivam 
Published: December 2024

ABSTRACT

Introduction:
Congenital heart disease (CHD)-associated malnutrition is a systemic consequence of CHD. Dietary recommendations to fulfill nutritional requirements are lacking. This randomized controlled trial (RCT) was conducted to determine the efficacy of early enteral feeding with supplemented expressed breast milk (suppl-EBM) versus expressed breast milk (EBM) in improving the weight of postoperative cardiac surgical infants.

Objective:
The primary objective was the weight change between the EBM group and the suppl-EBM group at the 15th postoperative day (POD) or intensive care unit (ICU) discharge. The secondary objectives were to compare the ventilation duration (VD), length of ICU stay (LOICUS), length of hospital stay (LOHS), macronutrient consumption, adverse events, sepsis, and mortality between the two groups.

Materials and Methods:
This study was a parallel-group, open-labeled, single-blinded, variable block size RCT conducted at a tertiary care teaching hospital in northern India. Full-term breastfed infants ≤6 months, weighing ≥2.5 kg at birth, and undergoing congenital cardiac repair were enrolled in this study. The infants were fed either EBM or supplemented EBM in control and intervention groups, respectively. Weight and length were measured at baseline and 15th POD or at ICU discharge. Biochemical parameters at baseline and every alternate day, sepsis parameters every third POD and VD, LOICUS, LOHS, macronutrient consumption, and adverse events were assessed daily.

Results:
The mean weight, weight change percentage, and weight for age z score were significantly higher in the supplemented EBM group (P < 0.05). The macronutrient consumption was significantly higher in the intervention group (P < 0.05). No significant difference was found between the two groups for VD, LOICUS, and LOHS (P > 0.05). The sepsis was higher in the EBM group. However, the mortality rate did not differ between the two groups (P > 0.05).

Conclusion:
Supplemented feeding may improve the weight of postoperative cardiac infants with no serious adverse events.
Thoracic Segmental Spinal Anesthesia in Kyphoplasty: A Case Series
Authors: Haloi Prajnananda , Biswas Rahul , Bora Ananta Kumar , Mahanta Dipanjali , Choudhury Dhrubajyoti 
Published: December 2024

Abstract
Kyphoplasty is a minimally invasive surgical procedure of the spine used to treat osteoporotic vertebral fractures that commonly affect the elderly, postmenopausal women, and patients with osteoporotic bone disease. Prolonged immobility in these patients often results in multiple comorbidities. Anesthetic modalities that have been used in kyphoplasty include general anesthesia, monitored anesthesia care, lumbar spinal anesthesia, and interfacial plane blocks, each with its advantages and disadvantages. This study examines thoracic segmental spinal anesthesia (TSSA) as an innovative anesthetic modality in treating kyphoplasty. This study investigates the case of four patients undergoing L1 kyphoplasty to evaluate its safety and efficacy. TSSA was performed at the T11–T12 interspace, and 1.5 mL of 0.5% heavy bupivacaine with 60 μg of buprenorphine was injected. The patients were positioned in a prone position after achieving the desired block level. Blood pressure, pulse, oxygen saturation, and respiratory rate were monitored throughout the procedure. Postoperative pain was assessed using the visual analog scale. Any adverse events were documented. Assessment of the results demonstrated significant perioperative benefits, including stable hemodynamics, enhanced analgesia, and early motor recovery. None of the patients complained of pain or discomfort during the procedure, and there were no instances of hypotension, bradycardia, or respiratory depression. Thus, TSSA was found to be a safe and viable anesthetic option for kyphoplasty. Our preliminary findings indicate that TSSA combined with minimal sedation can improve patient outcomes and enhance perioperative pain management. More research is needed to validate its broader application in spinal surgery.
Application of Dynamic Navigation, Virtual Reality, and Universal Robot in Dental Implantology
Authors: Bhalerao Ashwini Abhay , Ayoub Ashraf Farouk , Usman Abdul Wahab 
Published: December 2024

Abstract
In recent years, technological advancements have revolutionized the landscape of dental implantology, paving the way for more precise, efficient, and patient-friendly procedures. This paper reviews this approach that integrates DN, Virtual Reality (VR), and Universal Robot (UR) systems to enhance the efficacy of zygomatic implant placement and overcome the limitations of conventional procedures. Dynamic Navigation (DN) offers real-time, three-dimensional guidance during implant placement, enabling precise positioning and optimal implant angulation. By incorporating DN into the workflow, clinicians can navigate anatomical complexities with unprecedented precision, minimizing the risk of surgical errors and enhancing patient outcomes.Virtual Reality (VR) technology immerses clinicians in a simulated environment, providing realistic training scenarios and procedural planning. By leveraging VR, practitioners can simulate complex dental implant surgeries, refine their skills, and anticipate potential challenges before stepping into the operating room, thereby improving surgical proficiency and patient safety. The integration of Universal Robot (UR) systems introduces automation and robotic assistance into the implantology workflow, augmenting the capabilities of dental professionals and ensuring consistent, reproducible results. UR systems enable precise drilling, implant placement, and tissue manipulation, reducing procedural variability and optimizing implant success rates. This innovative integration of DN, VR, and UR systems represents a paradigm shift in dental implantology, offering clinicians unprecedented precision, efficiency, and predictability. By harnessing the synergies of these cutting-edge technologies, dental professionals can elevate the standard of care, redefine treatment protocols, and ultimately enhance patient satisfaction and oral health outcomes.