bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tracing the Propagation of Shocks in the Equatorial Ring of SN 1987A over Decades with the Hubble Space Telescope
Authors: Tegkelidis Christos , Larsson Josefin , Fransson Claes 
Published: November 2024

Abstract
The nearby SN 1987A offers a unique opportunity to investigate the complex shock interaction between the ejecta and circumstellar medium. We track the evolution of the optical hot spots within the equatorial ring (ER) by analyzing 33 Hubble Space Telescope imaging observations between 1994 and 2022. By fitting the ER with an elliptical model, we determine its inclination to be 42.°85 ± 0.°50 with its major axis oriented −6.°24 ± 0.°31 from the west. We identify 26 distinct hot spots across the ER, with additional ones emerging over time, particularly on the western side. The hot spots initially show high velocities ranging from 390 to 1660 km s−1, followed by a deceleration phase around day ∼ 8000. Subsequent velocities vary from 40 to 660 km s−1. The light curves of the hot spots reach maxima between 7000 and 9000 days, suggesting a connection with the deceleration. Many spots are spatially resolved and show elongation perpendicular to the direction of motion, indicative of a short cooling time. To explain these results, we propose that each hot spot comprises dense substructures embedded in less dense gas. The initial velocities are then phase velocities, where the break occurs when the blast wave leaves the ER, while the late velocities reflect the propagation of radiative shocks in the dense substructures. We estimate that the dense substructures have a volumetric filling factor of

∼
0.3

n
e

/

10
6

cm

−
3

−
2

%

and a total mass of

∼
0.24

n
e

/

10
6

cm

−
3

−
1

×

10

−
2

M
⊙

.
Holographic Beam Measurements of the Canadian Hydrogen Intensity Mapping Experiment (CHIME)
Authors: Amiri Mandana , Chakraborty Arnab , Foreman Simon , Halpern Mark , Hill Alex S , Hinshaw Gary , Landecker T. L. , MacEachern Joshua , Masui Kiyoshi W. , Mena-Parra Juan , Milutinovic Nikola , Newburgh Laura , Ordog Anna , Pen Ue-Li , Pinsonneault-Marotte Tristan , Reda Alex , Siegel Seth R. , Singh Saurabh , Wang Haochen , Wulf Dallas ,   The CHIME Collaboration
Published: November 2024

Abstract
We present the first results of the holographic beam-mapping program for the Canadian Hydrogen Intensity Mapping Experiment (CHIME). We describe the implementation of a holographic technique as adapted for CHIME, and introduce the processing pipeline which prepares the raw holographic timestreams for analysis of beam features. We use data from six bright sources across the full 400–800 MHz observing band of CHIME to provide measurements of the copolar and cross-polar beam response in both amplitude and phase for all 1024 dual-polarized feeds in the array. In addition, we present comparisons with independent probes of the CHIME beam, which indicate the presence of polarized beam leakage. Holographic measurements of the beam have already been applied in science with CHIME, e.g., in estimating the detection significance of far-sidelobe fast radio bursts, and in validating the beam models used for CHIME’s first detections of 21 cm emission (in cross-correlation with measurements of large-scale structure from galaxy surveys and the Lyα forest). Measurements presented in this paper, and future holographic results, will provide a unique data set to characterize the CHIME beam and improve the experiment’s prospects for a detection of the baryon acoustic oscillation signal.
Equilibrium States of Galactic Atmospheres. I. The Flip Side of Mass Loading
Authors: Voit G. Mark , Pandya Viraj , Fielding Drummond B. , Bryan Greg L. , Carr Christopher , Donahue Megan , Oppenheimer Benjamin D. , Somerville Rachel S. 
Published: November 2024

Abstract
This paper presents a new framework for understanding the relationship between a galaxy and its circumgalactic medium (CGM). It focuses on how imbalances between heating and cooling cause either expansion or contraction of the CGM. It does this by tracking all of the mass and energy associated with a halo’s baryons, including their gravitational potential energy, even if feedback has pushed some of those baryons beyond the halo’s virial radius. We show how a star-forming galaxy’s equilibrium state can be algebraically derived within the context of this framework, and we analyze how the equilibrium star formation rate depends on supernova feedback. We consider the consequences of varying the mass loading parameter

η

M

≡

M

̇

wind

/

M

̇

*

relating a galaxy’s gas mass outflow rate (

M

̇

wind

) to its star formation rate (

M

̇

*

) and obtain results that challenge common assumptions. In particular, we find that equilibrium star formation rates in low-mass galaxies are generally insensitive to mass loading, and when mass loading does matter, increasing it actually results in more star formation because more supernova energy is needed to resist atmospheric contraction.
Proposed Importance of HOCO Chemistry: Inefficient Formation of CO2 from CO and OH Reactions on Ice Dust
Authors: Ishibashi Atsuki , Molpeceres Germán , Hidaka Hiroshi , Oba Yasuhiro , Lamberts Thanja , Watanabe Naoki 
Published: November 2024

Abstract
With the advent of JWST ice observations, dedicated studies on the formation reactions of detected molecules are becoming increasingly important. One of the most interesting molecules in interstellar ice is CO2. Despite its simplicity, the main formation reaction considered, CO + OH → CO2 + H through the energetic HOCO* intermediate on ice dust, is subject to uncertainty because it directly competes with the stabilization of HOCO as a final product, which is formed through energy dissipation of HOCO* to the water ice. When energy dissipation to the surface is effective during the reaction, HOCO can be a dominant product. In this study, we experimentally demonstrate that the major product of the reaction is indeed not CO2, but rather the highly reactive radical HOCO. The HOCO radical can later evolve into CO2 through H-abstraction reactions, but these reactions compete with additional reactions, leading to the formation of carboxylic acids (R-COOH). Our results highlight the importance of HOCO chemistry and encourage further exploration of the chemistry of this radical.
Exploration of Halo Substructures in Integrals-of-motion Space with Gaia Data Release 3
Authors: Liu Haoyang , Du Cuihua , Ye Dashuang , Zhang Jian , Deng Mingji 
Published: November 2024

Abstract
Using kinematic data from the Gaia Data Release 3 catalog, along with metallicity estimates robustly derived from Gaia BP/RP spectra, we have explored the Galactic stellar halo in search of both known and potentially new substructures. By applying the Hierarchical Density-Based Spatial Clustering of Applications with Noise clustering algorithm in integrals-of-motion space (i.e., E, L

z
, and L
⊥

=

L

x

2

+

L

y

2

), we identified five previously known substructures: Gaia-Sausage-Enceladus (GSE), Helmi streams, I'itoi and Sequoia, and the hot thick disk. We additionally found NGC 3201 and NGC 5139 in this work, and NGC 3201 shares similar distributions in phase space and metallicities to Arjuna, which possibly implies that they have the same origin. Three newly discovered substructures are Prograde Substructure 1 (PG1), Prograde Substructure 2 (PG2), and the Low Energy Group. PG1, with a higher V

ϕ
than typical GSE member stars, is considered as either a low-eccentricity and metal-rich part of GSE or part of the metal-poor disk. PG2, sharing kinematic similarities with Aleph, is thought to be its relatively highly eccentric component or the mixture of Aleph and the disk. The Low Energy Group, whose metal-poor component of metallicity distribution function has a mean value [M/H] ∼ −1.29 (compared to that of Heracles [M/H] ∼ −1.26), may have associations with Heracles.
WALLABY Pilot Survey: Gas-rich Galaxy Scaling Relations from Marginally Resolved Kinematic Models
Authors: Deg N. , Arora N. , Spekkens K. , Halloran R. , Catinella B. , Jones M. G. , Courtois H. , Glazebrook K. , Bosma A. , Cortese L. , Dénes H. , Elagali A. , For B.-Q. , Kamphuis P. , Koribalski B. S. , Lee-Waddell K. , Mancera Piña P. E. , Mould J. , Rhee J. , Shao L. , Staveley-Smith L. , Wang J. , Westmeier T. , Wong O. I. 
Published: November 2024

Abstract
We present the first set of galaxy scaling relations derived from kinematic models of the Widefield Australian Square Kilometer Array Pathfinder (ASKAP) L-band Legacy All-sky Blind surveY (WALLABY) pilot phase observations. Combining the results of the first and second pilot data releases, there are 236 available kinematic models. We develop a framework for robustly measuring H i disk structural properties from these kinematic models, applicable to the full WALLABY survey. Utilizing this framework, we obtained the H i size, a measure of the rotational velocity, and angular momentum for 148 galaxies. These comprise the largest sample of galaxy properties from an untargeted, uniformly observed, and modeled H i survey to date. We study the neutral atomic hydrogen (H i) size–mass, size–velocity, mass–velocity, and angular momentum–mass scaling relations. We calculate the slope, intercept, and scatter for these scaling relations and find that they are similar to those obtained from other H i surveys. We also obtain stellar masses for 92 of the 148 robustly measured galaxies using multiband photometry through Dark Energy Sky Instrument Legacy Imaging Survey Data Release 10 images. We use a subset of 61 of these galaxies that have consistent optical and kinematic inclinations to examine the stellar and baryonic Tully–Fisher relations as well as the gas fraction–disk stability and gas fraction–baryonic mass relations. These measurements and relations demonstrate the unprecedented resource that WALLABY will represent for resolved galaxy scaling relations in H i.
Evolutionary States and Triplicity of Four Massive Semidetached Binaries with Long-term Decreasing Orbital Periods in the LMC
Authors: Li Fu-Xing , Qian Sheng-Bang , Zhu Li-ying , Liao Wen-Ping , Zhao Er-gang , Li Min-Yu , Sun Qi-Bin , Chang Lin-Feng , Lin Wen-Xu 
Published: November 2024

Abstract
The massive semidetached binary with a long-term decreasing orbital period may involve a rapid mass-transfer phase in Case A, and thus, they are good astrophysical laboratories for investigating the evolution of massive binary stars. In this work, by using the long-term observational light curves from the Optical Gravitational Lensing Experiment project and other data in the low-metallicity Large Magellanic Cloud, four semidetached massive binaries with long-term decreases in the orbital periods are detected from 165 EB-type close binaries. It is found that the more massive component in S07798 is filling its Roche lobe, where the period decrease is caused by mass transfer from the primary to the secondary. However, the other three (S03065, S12631, S16873) are semidetached binaries with a lobe-filling secondary where the mass transfer between the components should cause the period to increase if the angular momentum is conservative. The long-term period decreases in these three systems may be caused by angular momentum loss. Additionally, the orbital periods of three systems (S03065, S07798, S16873) are detected to show cyclic variation with periods shorter than 11 yr, which can be plausibly explained by the presence of close-in third bodies in these massive binaries. Based on all of these results, it is suggested that the detected four semidetached binaries almost have multiplicity. The companion stars are crucial for the origin and evolution of these massive close binaries.
Streaming Instabilities in Accreting Protoplanetary Disks: A Parameter Study
Authors: Wang Shiang-Chih , Lin Min-Kai 
Published: November 2024

Abstract
The streaming instability (SI) is currently the leading candidate for triggering planetesimal formation in protoplanetary disks. Recently, a novel variation, the “azimuthal-drift” streaming instability (AdSI), was discovered in disks exhibiting laminar gas accretion. Unlike the classical SI, the AdSI does not require pressure gradients and can concentrate dust even at low abundances. We extend previous simulations of the AdSI to explore the impact of dust abundance, accretion-flow strength, pressure gradients, and grain size. For a dimensionless accretion-flow strength α
M = 0.1 and particle Stokes number St = 0.1, we find the AdSI produces dust filaments for initial dust-to-gas ratios as low as ϵ = 0.01. For ϵ ≳ 1, maximum dust-to-gas ratios of order 100 are attained, which can be expected to undergo gravitational collapse. Furthermore, even in systems dominated by the classical SI, an accretion flow drives filament formation, without which the disk remains in a state of small-scale turbulence. Our results suggest that an underlying accretion flow facilitates dust concentration and may thus promote planetesimal formation.
Constraints on Remnant Planetary Systems as a Function of Main-sequence Mass with HST/COS
Authors: Ould Rouis Lou Baya , Hermes J. J. , Gänsicke Boris T. , Sahu Snehalata , Koester Detlev , Tremblay P.-E. , Veras Dimitri , Farihi Jay , Heintz Tyler M. , Gentile Fusillo Nicola Pietro , Redfield Seth 
Published: November 2024

Abstract
As the descendants of stars with masses less than 8 M
⊙ on the main sequence, white dwarfs provide a unique way to constrain planetary occurrence around intermediate-mass stars (spectral types BAF) that are otherwise difficult to measure with radial-velocity or transit surveys. We update the analysis of more than 250 ultraviolet spectra of hot (13,000 K < T
eff < 30,000 K), young (less than 800 Myr) white dwarfs collected by the Hubble Space Telescope, which reveals that more than 40% of all white dwarfs show photospheric silicon and sometimes carbon, signposts for the presence of remnant planetary systems. However, the fraction of white dwarfs with metals significantly decreases for massive white dwarfs (M
WD > 0.8 M
⊙), descendants of stars with masses greater than 3.5 M
⊙ on the main sequence, as just

11

−
4

+
6

% exhibit metal pollution. In contrast, 44% ± 6% of a subset of white dwarfs (M
WD < 0.7 M
⊙) unbiased by the effects of radiative levitation are actively accreting planetary debris. While the population of massive white dwarfs is expected to be influenced by the outcome of binary evolution, we do not find merger remnants to broadly affect our sample. We connect our measured occurrence rates of metal pollution on massive white dwarfs to empirical constraints of planetary formation and survival around stars with masses greater than 3.5 M
⊙ on the main sequence.
Could the Interband Lag of Active Galactic Nucleus Vary Randomly?
Authors: Su Zhen-Bo , Cai Zhen-Yi , Wang Jun-Xian , Wang Tinggui , Xue Yongquan , Cai Min-Xuan , Fan Lulu , Guo Hengxiao , He Zhicheng , He Zizhao , Hu Xu-Fan , Jiang Ji-an , Jiang Ning , Kang Wen-Yong , Lei Lei , Liu Guilin , Liu Teng , Liu Zhengyan , Sheng Zhenfeng , Sun Mouyuan , Zhao Wen 
Published: November 2024

Abstract
The interband lags among the optical broad-band continua of active galactic nuclei (AGNs) have been intensively explored over the past decade. However, the nature of the lags remains under debate. Here, utilizing two distinct scenarios for AGN variability, i.e., the thermal fluctuation of accretion disk and the reprocessing of both the accretion disk and clouds in the broad line region, we show that, owing to the random nature of AGN variability, the interband lags of an individual AGN would vary from one campaign with a finite baseline to another. Specifically, the thermal fluctuation scenario implies larger variations in the lags than the reprocessing scenario. Moreover, the former predicts a positive correlation between the lag and variation amplitude, while the latter does not result in such a correlation. For both scenarios, averaging the lags of an individual AGN measured with repeated and nonoverlapping campaigns would give rise to a stable lag, which is larger for a longer baseline and gets to saturation for a sufficiently long baseline. However, obtaining the stable lag for an individual AGN is very time-consuming. Alternatively, it can be equivalently inferred by averaging the lags of a sample of AGNs with similar physical properties, and thus can be properly compared with predictions of AGN models. In addition, several new observational tests suggested by our simulations are discussed, as well as the role of the deep high-cadence surveys of the Wide Field Survey Telescope in enriching our knowledge of the lags.
Test of Cosmic Web-feeding Model for Star Formation in Galaxy Clusters in the COSMOS Field
Authors: Ko 고 Eunhee 은희 , Im Myungshin , Lee Seong-Kook , Laigle Clotilde 
Published: November 2024

Abstract
It is yet to be understood how large-scale environments influence star formation activity in galaxy clusters. One recently proposed mechanism is that galaxy clusters can remain star forming when fed by infalling groups and star-forming galaxies from large-scale structures (LSSs) surrounding them (the “web-feeding” model). Using the COSMOS2020 catalog that has half a million galaxies with high-accuracy (σ
Δz/1+z
∼ 0.01) photometric redshifts, we study the relationship between star formation activities in galaxy clusters and their surrounding environment to test the web-feeding model. We first identify 68 cluster candidates at 0.3 ≤ z ≤ 1.4 with halo masses at 1013.0–1014.5
M
⊙ and the surrounding LSSs with the friends-of-friends algorithm. We find that clusters with low fractions of quiescent galaxies tend to be connected with extended LSSs as expected in the web-feeding model. We also investigated the time evolution of the web-feeding trend using the IllustrisTNG cosmological simulation. Even though no clear correlation between the quiescent galaxy fraction of galaxy clusters and the significance of LSSs around them is found in the simulation, we verify that the quiescent galaxy fractions of infallers such as groups (M
200 ≥ 1012
M
⊙) and galaxies (M
200 < 1012
M
⊙) are smaller than the quiescent fraction of cluster members and that infallers can lower the quiescent fraction of clusters. These results imply that cluster-to-cluster variations of quiescent galaxy fraction at z ≤ 1 can at least partially be explained by feeding materials through cosmic webs to clusters.
Multispectral Sirens: Gravitational-wave Cosmology with (Multi-) Subpopulations of Binary Black Holes
Authors: Li 李 Yin-Jie 银杰 , Tang 唐 Shao-Peng 少鹏 , Wang 王 Yuan-Zhu 远瞩 , Fan 范 Yi-Zhong 一中 
Published: November 2024

Abstract
The cosmic expansion rate can be directly measured with gravitational-wave (GW) data of the compact binary mergers by jointly constraining the mass function of the population and the cosmological model via the so-called spectral sirens. Such a method relies on the features in the mass functions, which may originate from some individual subpopulations and hence become blurred/indistinct due to the superposition of different subpopulations. In this work, we propose a novel approach to constrain the cosmic expansion rate with subpopulations of GW events, named multispectral sirens. The advantage of the multispectral sirens compared to the traditional spectral sirens is demonstrated by the simulation with the mock data. The application of this approach to the GWTC-3 data yields

H

0

=

73.3

−
25.6

+
29.9

Mpc

−
1

km

s

−
1

(median and symmetric 68.3% credible interval), which is about 19% tighter than the result inferred with the traditional spectral sirens utilizing a powerlaw+peak mass function. The incorporation of the bright standard siren GW170817 with a uniform prior in [10, 200] (log-uniform prior in [20,140]) Mpc−1 km s−1 gives

H

0

=

71.1

−
7.5

+
15.0

(

70.3

−
7.1

+
12.9

)

Mpc

−
1

km

s

−
1

(68.3% confidence level), corresponding to an improvement of ∼26% (23%) with respect to the measurement from sole GW170817.
The Dehydration of Serpentines and Extraction of Water
Authors: Pohl Leos , Britt Daniel T. 
Published: November 2024

Abstract
Some groups of carbonaceous chondrites are dominated by phyllosilicates, specifically the serpentine group, which are characterized as alternating layers of silicates, metal cations, and hydroxyl (OH). Both antigorite, an Mg-rich member, and cronstedtite, an Fe-rich member, can be found in hydrated carbonaceous chondrites. Cronstedtite is found in substantial amounts in CM chondrites. The hydroxyl can make up to a quarter of the molecular mass, and part of it can turn into molecular water through thermal-induced crystal structure breakup. Understanding how the water is released through thermal effects is important for describing the history of certain near-Earth asteroids, as well as for ascertaining the viability of in situ resource utilization (ISRU) for a given object. Here we investigate the temperature of dehydration of the main serpentine constituents of carbonaceous chondrites—antigorite, lizardite, and cronstedtite—under both atmospheric and vacuum conditions. Our results show that the mass loss for cronstedtite starts at about 150 °C lower temperature than for the Mg serpentines. Additionally, vacuum does not affect significantly the onset of the mass loss, but it affects its dynamics. Finally, our observations suggest that cronstedtite loses additional oxygen molecules besides the ones contained within the hydroxyl. These results provide an important new perspective on the orbital history of certain asteroids and the required proximity to the Sun in order for them to lose water. Additionally, it puts the CM-type asteroids on the center stage for ISRU.
Development and Validation of the Immediate Postpartum Care Adherence Questionnaire: An Application of the Theory of Planned Behavior among Healthcare Professionals
Authors: Al-Rajabi Omymah Z. , Abushaikha Lubna A. , Hadid Lourance A. Al 
Published: November 2024

Background:
The postpartum period is critical for women and newborns. Many complications, such as deaths, are preventable by utilizing appropriate postpartum care. We aimed to assess healthcare professionals’ adherence to the World Health Organization’s (WHO) immediate postpartum care guidelines, investigating factors influencing their adoption at Jordanian hospitals.

Materials and Methods:
A methodological study design, developing, and testing the psychometric properties of the Immediate Postpartum Care Adherence Questionnaire (IPCAQ) was created based on the Theory of Planned Behavior, extensive literature review, and the WHO guidelines following a manual construct questionnaire, and using a deductive method. The IPCAQ was developed using four steps: domain identification, scale construction, judgmental evidence, and psychometric evaluation.

Results:
The final draft of IPCAQ consisted of four domains and 63 items deductively formulated from the theoretical constructs. The domains are attitudes, behavioral intention, subjective norms, and perceived behavioral control. They were subsumed by four subthemes, general caring assessment, counseling, subjective norms, and perceived behavioral control. The IPCA showed high content (0.94) and face validity indices (0.97), moderate content scale universal agreement (0.77), and excellent face agreement (0.81) for the 63 items. IPCAQ is a reliable instrument that measures adherence to immediate postpartum care guidelines.

Conclusions:
IPCAQ is reliable and valid in the current sample. The IPCAQ can be used to assess healthcare professionals’ adherence to immediate postpartum care guidelines, identify factors influencing the adoption of standardized care to overcome barriers to adherence, and facilitate high-quality care.