bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photometric and Spectroscopic Analysis of Eight Totally Eclipsing Contact Binaries with Small Mass Ratios
Authors: Wang Li-Heng , Li Kai , Guo Ya-Ni , Wang Jing-Yi , Gao Xiang , Gao Xing , Sun Guo-You 
Published: November 2024

Abstract
This paper selected eight totally eclipsing contact binaries for photometric and spectroscopic studies. Spectral data were analyzed by University of Lyon Spectroscopic analysis Software, and photometric data were analyzed using PHOEBE through Markov Chain Monte Carlo (MCMC) sampling. We used two methods to calculate the initial values for running MCMC: one method is a new approach proposed by ourselves to model light curves without spots, while the other method is the genetic algorithm, which can determine physical parameters with spots. The results imply that these eight targets are all contact binary stars with a small mass ratio below 0.25. There are four systems exhibiting the O’Connell effect. By adding a dark spot on the primary component, the ideal fitting can be obtained. Meanwhile, it was found that two systems are shallow contact binaries, while the remaining six are moderate contact binaries. An O − C analysis of the eight eclipsing binary stars revealed that seven of them exhibit long-term changes. Four of them display a long-term decreasing trend in orbital period, while the other three show a long-term increasing trend, and two targets exhibit periodic variations. A decrease in period may be caused by the transfer of matter from the more massive component to the less massive component, while an increase in period may be caused by transfer in the opposite way. The absolute physical parameters, orbital angular momentum, initial masses, and ages of these eight systems were calculated. Additionally, their mass–luminosity and mass–radius distributions were analyzed.
Constraining the Low-mass End of the Stellar-to-halo Mass Relation with Surveys of Satellite Galaxies
Authors: Monzon J. Sebastian , van den Bosch Frank C. , Mitra Kaustav 
Published: November 2024

Abstract
The abundance of satellite galaxies is set by the hierarchical assembly of their host halo. We leverage this to investigate the low-mass end (M
H < 1011
M
⊙) of the stellar-to-halo mass relation (SHMR), which is key to constraining theories of galaxy formation and cosmology. We argue that recent analyses of satellite galaxies in the Local Group environment have not adequately modeled the dominant source of scatter in satellite stellar mass functions: the variance in accretion histories for a fixed host halo mass. We present a novel inference framework that not only properly accounts for this halo-to-halo variance but also naturally identifies the amount of host halo mass mixing, which is generally unknown. Specifically, we use the semianalytical SatGen model to construct mock satellite galaxy populations consistent with the third data release of the Satellites Around Galactic Analogs survey. We demonstrate that even under the most idealized circumstances, the halo-to-halo variance makes it virtually impossible to put any meaningful constraints on the scatter in the SHMR. Even a satellite galaxy survey made up 100 hosts can at best only place an upper limit of ∼0.5 dex on the scatter (at the 95% confidence level). This is because the large variance in halo assembly histories dominates over the scatter in the SHMR. This problem can be overcome by increasing the sample size of the survey by an order of magnitude (∼1000 host galaxies), something that should be fairly straightforward with forthcoming spectroscopic surveys.
Expanding the Inventory of Molecule-rich Planetary Nebulae: New Observations of M4-17, Hu 1-1, M1-59, and Na 2
Authors: Gold K. R. , Schmidt D. R. , Ziurys L. M. 
Published: November 2024

Abstract
Molecular observations of four planetary nebulae (PNe), M4-17, Hu 1-1, M1-59, and Na 2, were conducted at 1–3 mm using the Arizona Radio Observatory’s 12 m antenna and Submillimeter Telescope, and the Institut de Radioastronomie Millimétrique 30 m Telescope. Toward M4-17, HNC (J = 3 → 2), CCH (N = 2 → 1, N = 3 → 2), CN (N = 1 → 0, N = 2 → 1), H2CO (J
Ka,Kc = 21,2 → 11,1, J
Ka,Kc = 20,2 → 10,1, J
Ka,Kc = 21,1 → 11,0), CS (J = 3 → 2, J = 5 → 4), and H13CN (J = 2 → 1) were detected. An almost identical set of transitions was identified toward Hu 1-1. Moreover, c–C3H2 was detected in Hu 1-1 via three 2 mm lines: J
Ka,Kc = 31,2 → 22,1, J
Ka,Kc = 41,4 → 30,3, and J
Ka,Kc = 32, 2 → 21,1. HNC, CCH, CN, CS, and H13CN were found in M1-59, as well as H2S via its J
Ka,Kc = 11,0 → 10,1 line—the first detection of this key sulfur species in PNe. In addition, CCH and CN were identified in the 27,000 yr old Na 2. Among these four sources, CN and CCH were the most prevalent molecules (after CO and H2) with fractional abundances, relative to H2, of f ∼ 0.9–7.5 × 10−7 and 0.8–7.5 × 10−7, respectively. CS and HNC have abundances in the range f ∼ 0.5–5 × 10−8, the latter resulting in HCN/HNC ∼ 3 across all three PNe. The unusual species H2CO, c–C3H2, and H2S had f ∼ 3–4 × 10−7, 10−8, and 6 × 10−8. This study suggests that elliptical PNe such as Hu 1-1 can have a diverse molecular composition. The presence of CN, CCH, and HCO+ in Na 2, with comparable abundances to younger PNe, demonstrates that molecular content is maintained into the late PN stage.
Between the Extremes: A JWST Spectroscopic Benchmark for High-redshift Galaxies Using ∼500 Confirmed Sources at z ≥ 5
Authors: Roberts-Borsani Guido , Treu Tommaso , Shapley Alice , Fontana Adriano , Pentericci Laura , Castellano Marco , Morishita Takahiro , Bergamini Pietro , Rosati Piero 
Published: November 2024

Abstract
The exceptional spectra of the most luminous z > 10 sources observed so far have challenged our understanding of early galaxy evolution, requiring a new observational benchmark for meaningful interpretation. As such, we construct spectroscopic templates representative of high-redshift, star-forming populations, using 482 confirmed sources at z = 5.0−12.9 with JWST/NIRSpec prism observations, and report on their average properties. We find z = 5−11 galaxies are dominated by blue UV continuum slopes (β = −2.3 to −2.7) and reduced Balmer indices, characteristic of dust-poor and young systems, with a shift towards bluer slopes and younger ages with redshift. The evolution is mirrored by ubiquitous C iii] detections across all redshifts (rest-frame equivalent widths of 5−14 Å), which increase in strength towards early times. Rest-frame optical lines reveal elevated ratios (O32 = 7–31, R23 = 5–8, and Ne3O2 = 1−2) and subsolar metallicities (log(O/H) = 7.3−7.9), typical of ionization conditions and metallicities rarely observed in z ∼ 0 populations. Within our sample, we identify 57 Lyα emitters, which we stack and compare to a matched sample of nonemitters. The former are characterized by more extreme ionizing conditions with enhanced C iii], C iv, and He ii + [O iii] line emission, younger stellar populations from Balmer jumps, and a more pristine interstellar medium seen through bluer UV slopes and elevated rest-frame optical line ratios. The novel comparison illustrates important intrinsic differences between the two populations, with implications for Lyα visibility. The spectral templates derived here represent a new observational benchmark with which to interpret high-redshift sources, lifting our constraints on their global properties to unprecedented heights and extending out to the earliest of cosmic times.
Radial Distribution of Electron Quasi-thermal Noise in the Inner Heliosphere
Authors: Li 李 Yi-Lun 逸伦 , Chen 陈 Ling 玲 , Wu 吴 De-Jin 德金 
Published: November 2024

Abstract
The electron population in the solar wind plasma can be described with three different components: a core, a halo, and a magnetic field aligned strahl. The electron quasi-thermal noise (QTN) is investigated by using an electron population model consisting of a core with a Maxwellian distribution and a halo with a kappa distribution, based on the empirical equations for electron density and temperature and the index for the kappa halo. The power spectra of the electron QTN are calculated at different heliocentric radial distances from 10 to 200 R

s
. The dependence of the QTN spectrum and effective Debye length on model parameters, including the ratio of the halo to the core for the density and temperature, the kappa index, and the antenna length, is further discussed. The results show that the electron QTN spectrum consists of a plateau in the low-frequency band f < f

pt
, a peak at the total plasma frequency f

pt
, and a rapidly decreasing part in the high-frequency band f > f

pt
. The QTN peak and plateau level continuously decrease as the radial distance increases, with the peak’s shape changing due to the variation of the kappa index. Although the model parameters are variable, the QTN plateau level presents less than an order of change with these parameters changing greatly, and only a monotonic change of the plateau is shown when the parameters are close to the practical situation. The results can provide a reference for future deep-space exploration in the inner heliosphere, and also for the design of detectors.
Strong Nongravitational Accelerations and the Potential for Misidentification of Near-Earth Objects
Authors: Taylor Aster G. , Seligman Darryl Z. , Holman Matthew J. , Vereš Peter , Farnocchia Davide , Lewis Nikole , Micheli Marco , Wright Jason T. 
Published: November 2024

Abstract
Nongravitational accelerations in the absence of observed activity have recently been identified on near-Earth objects (NEOs), opening the question of the prevalence of anisotropic mass loss in the near-Earth environment. Motivated by the necessity of nongravitational accelerations to identify 2010 VL65 and 2021 UA12 as a single object, we investigate the problem of linking separate apparitions in the presence of nongravitational perturbations. We find that nongravitational accelerations on the order of 1 × 10–9 au day−2 can lead to a change in plane-of-sky positions of ∼1 × 103 arcsec between apparitions. Moreover, we inject synthetic tracklets of hypothetical nongravitationally accelerating NEOs into the Minor Planet Center orbit identification algorithms. We find that at large nongravitational accelerations (∣A

i
∣ ≥ 1 × 10−8 au day−2) these algorithms fail to link a significant fraction of these tracklets. We further show that if orbits can be determined for both apparitions, the tracklets will be linked regardless of nongravitational accelerations, although they may be linked to multiple objects. In order to aid in the identification and linkage of nongravitationally accelerating objects, we propose and test a new methodology to search for unlinked pairs. When applied to the current census of NEOs, we recover the previously identified case but identify no new linkages. We conclude that current linking algorithms are generally robust to nongravitational accelerations, but objects with large nongravitational accelerations may potentially be missed. While current algorithms are well-positioned for the anticipated increase in the census population from future survey missions, it may be possible to find objects with large nongravitational accelerations hidden in isolated tracklet pairs.
Stellar Bars Form Dark Matter Counterparts in TNG50
Authors: Ash Neil , Valluri Monica , Chen Yingtian , Bell Eric F. 
Published: November 2024

Abstract
Dark matter (DM) bars that shadow stellar bars have been previously shown to form in idealized simulations of isolated disk galaxies, but have yet to be studied in a fully cosmological context. In this work, we analyze a population of disk galaxies within the TNG50 simulation to determine the characteristics of their dark bars. We estimate bar strength and orientation using both the in-plane Fourier A
2 density moments and the quadrupolar coefficients of the spherical harmonic basis function expansions of the density. We additionally present two novel methods for measuring the bar pattern speed Ω
p
and rotation axis orientation using these coefficients, and apply them to one sample galaxy located in a TNG50 subbox. Consistent with isolated simulations, DM bars are shorter than their stellar counterparts and are 75% weaker in A
2. DM bars dominate the shape of the inner halo potential and are apparent in the time series of quadrupolar coefficients. In our selected subbox galaxy, the stellar and dark bars remain co-aligned throughout the last 8 Gyr and have identical Ω
p
. Pattern speed Ω
p
evolves considerably over the last 8 Gyr, consistent with torques on the bars due to dynamical friction and gas accretion, and is seen to increase following a merger at t

lb
= 1.5 Gyr. Rather than remaining static in time, the bar rotation axis displays both precession and nutation possibly caused by torques outside the plane of rotation. We find that the shape of the stellar and DM mass distributions are tightly correlated with Ω
p
.
SN 1885A and Supernova Remnants in the Centre of M31 with LOFAR
Authors: Venkattu Deepika , Lundqvist Peter , Pérez Torres Miguel , Bonnassieux Etienne , Tasse Cyril , Melchior Anne-Laure , Combes Francoise 
Published: November 2024

Abstract
We present the first LOFAR image of the center of M31 at a frequency of 150 MHz. We clearly detect three supernova remnants, which, along with archival VLA data at 3 GHz and other published radio and X-ray data, allows us to characterize them in detail. Our observations also allow us to obtain upper limits of the historical SN 1885A, which is undetected even at a low frequency of 150 MHz. From analytical modeling, we find that SN 1885A will stay in its free-expansion phase for at least another couple of centuries. We find an upper limit of n
H ≲ 0.04 cm−3 for the interstellar medium of SN 1885A, and that the SN ejecta density is not shallower than ∝r
−9 (on average). From the 2.6σ tentative detection in X-ray, our analysis shows that nonthermal emission is expected to dominate the SN 1885A emission. Comparing our results with those on G1.9+0.3, we find that it is likely that the asymmetries in G1.9+0.3 make it a more efficient radio and X-ray emitter than SN 1885A. For Braun 80, 95, and 101, the other remnants in this region, we estimate ages of 5200, 8100, and 13,100 yr, and shock speeds of 1150, 880, and 660 km s−1, respectively. Based on this, the supernova rate in the central 0.5 kpc × 0.6 kpc of M31 is at least one per ∼3000 yr. We estimate radio spectral indices of −0.66 ± 0.05, −0.37 ± 0.03, and −0.50 ± 0.03 for the remnants, respectively, which match fairly well with previous studies.
Interplanetary Rotation of 2021 December 4 Coronal Mass Ejection on Its Journey to Mars
Authors: Ma Mengxuan , Yang Liping , Shen Fang , Shen Chenglong , Chi Yutian , Wang Yuming , Zhou Yufen , Zhang Man , Heyner Daniel , Auster Uli , Richter Ingo , Sanchez-Cano Beatriz 
Published: November 2024

Abstract
The magnetic orientation of coronal mass ejections (CMEs) is of great importance to understand their space weather effects. Although plenty of evidence suggests that CMEs can undergo significant rotation during the early phases of evolution in the solar corona, there are few reports that CMEs rotate in the interplanetary space. In this work, we use multispacecraft observations and a numerical simulation starting from the lower corona close to the solar surface to understand the CME event on 2021 December 4, with an emphatic investigation of its rotation. This event is observed as a partial halo CME from the back side of the Sun by coronagraphs and reaches the BepiColombo spacecraft and the Mars Atmosphere and Volatile EvolutioN/Tianwen-1 as a magnetic flux-rope-like structure. The simulation discloses that in the solar corona the CME is approximately a translational motion, while the interplanetary propagation process evidences a gradual change of axis orientation of the CME’s flux-rope-like structure. It is also found that the downside and the right flank of the CME moves with the fast solar wind, and the upside does in the slow-speed stream. The different parts of the CME with different speeds generate the nonidentical displacements of its magnetic structure, resulting in the rotation of the CME in the interplanetary space. Furthermore, at the right flank of the CME exists a corotating interaction region, which makes the orientation of the CME alter and also deviates from its route due to the CME. These results provide new insight into interpreting CMEs’ dynamics and structures during their traveling through the heliosphere.
Model-independent Calibration for Sound Horizon: Combining Observations of Supernovae and Baryon Acoustic Oscillation Measurements
Authors: Liu Tonghua , Zhong Xinyi , Biesiada Marek , Wang Jieci 
Published: November 2024

Abstract
The sound horizon scale is a key theoretical prediction of the cosmological model that depends on the speed of sound in the baryon-photon fluid and the rate of expansion of the early Universe, before matter and radiation decoupled. Baryon acoustic oscillations (BAOs) offer the direct measurement of this important scale imprinted in the distribution of galaxies. We propose a new model-independent method to calibrate the sound horizon

r
s
h

(relative standard ruler) by using the latest observations of Type Ia supernovae (SNe Ia) and 2D BAO measurements. The final result is

r

s

h

=

107.10

−
1.32

+
1.36

Mpc h
−1 in the framework of the Pantheon SN Ia data set. This result changes to

r

s

h

=

105.63

−
1.31

+
1.33

Mpc h
−1 when the Pantheon+ data set is used. To highlight our analysis and results, we also use BAO DESI measurements and obtain the best-fitting value

r

s

h

=

100.83

−
0.95

+
0.99

Mpc h
−1. Note that even without an estimate of the dimensionless Hubble constant h, the combination of 2D BAO and SN Ia data sets already constrains the low-redshift standard ruler scale

r
s
h

at the ∼1.26% level (at the ∼1.00% level in the framework of BAO DESI data set). More importantly, it is interesting to note that most of the

r
s
h

obtained at high redshifts have systematically larger values: 9 out of 15 results are larger than the result obtained by combining all 2D BAOs. This finding may give us a better understanding of the discordance between the data sets, shed light on the Hubble tension, or reveal the need for new physics beyond the standard cosmological model.
Selected Problems in Friction Stir Welding of Titanium and Aluminum Armor Grade Alloys
Authors: Kosturek Robert , Torzewski Janusz , Wachowski Marcin , Grzelak Krzysztof , Śnieżek Lucjan 
Published: November 2024

In this paper, authors reported selected problems in friction stir welding (FSW) of 5 mm-thick AA7075-T651 and 3 mm-thick Ti6Al4V. The investigation involved macro and micro-structure analysis and mechanical testing. The welded joints of Ti6Al4V were characterized by the presence of backing plate steel fragments and tungsten particles in the bottom part of the stir zone (SZ) and thermo-mechanically affected zone (TMAZ), which resulted in a relatively low value of joint efficiency (60 %). The investigation on AA7075-T651 was concerned with high-speed FSW (HSFSW) using the MX Triflute tool. In all cases, defective welded joints have been obtained (incomplete root penetration, voids in the SZ) with the best result of joint efficiency of about 59 %.
La construction de la nouvelle capitale politique du Burundi à Gitega : aménagement urbain, discours sur la ville et « emblématisation »
Authors: Pasini Jérémy , Ngiye Érasme , Gahungu Dieudonné 
Published: November 2024

Depuis 2019, Gitega remplace Bujumbura comme capitale politique du Burundi. Dans ce contexte, l’article interroge les modalités de la transformation des espaces urbains de Gitega et des pratiques et discours collectifs qui y sont associés. Notre hypothèse centrale est que, pour fabriquer la nouvelle capitale, l’État burundais cherche à la distinguer des autres villes en la dotant d’infrastructures et de cadres de vie modernisés, tout en réaffirmant ses fonctions cérémoniales (processus d’« emblématisation »). Notre étude, qui s’appuie sur l’analyse d’entretiens semi-directifs avec des habitants de Gitega (natifs ou fonctionnaires délocalisés), de sources institutionnelles et d’images satellitaires, montre que la ville acquiert progressivement les attributs qui sont pensés par le gouvernement comme ceux relevant d’une capitale (constructions en hauteur, grands équipements, etc.). Toutefois, ces transformations s’accompagnent aussi de tensions sociales : dirigisme des processus d’aménagement urbain, scepticisme et opposition d’une partie de la population, relégation des ménages les plus pauvres en périphérie de la ville. En fait, la fabrique de la nouvelle capitale répond surtout à un processus de renforcement de l’État qui souhaite démontrer sa capacité à conduire de grands projets et mettre en scène une sorte de renouveau quelques années après la crise institutionnelle de 2015.
Billet de réflexion : Brasilia, « la ville qui n’aurait pas dû exister », vient de fêter ses 64 ans
Authors: Oliveira Márcio de 
Published: November 2024

Brasilia, « la ville qui n’aurait jamais dû exister », vient de fêter ses 64 ans. À l’heure actuelle, est-il possible de dire que l’aura et l’espoir soulevés au milieu du XXe siècle par le projet développementaliste et conquérant de l’ex-président Juscelino Kubitschek (1902-1976), confié au génie architectural d’Oscar Niemeyer et placé sous l’égide de l’urbaniste Lúcio Costa, restent de rigueur ? Revisitant les nombreux écrits sur ce projet-phare du modernisme brésilien, ce billet entend mettre en évidence les changements opérés dans la ville, qui sont autant d’écarts à l’idéal poursuivi par le projet développementaliste et ses expressions architecturales. Si l’affirmation de Brasilia comme capitale du Brésil a été progressive notamment en raison de l’urgence de sa construction et de la lenteur du processus de rééquilibrage politique et économique qui figurait au cœur du projet initial, elle a connu une série de réinventions qui en expliquent la place centrale qu’elle occupe aujourd’hui dans la scène urbaine, politique et culturelle du pays. Le billet revient sur quelques travaux consacrés à l’évolution de la ville depuis son inauguration, concluant sur le dynamisme de la scène culturelle, domaine qui constitue l’un des principaux atouts de l’actuelle capitale.
Aménagements en terrasses et dynamiques des systèmes ruraux dans les montagnes d’Afrique
Authors: Blond Ninon , Bart François , Lesourd Michel 
Published: November 2024

En Afrique, nombre de montagnes connaissent une dense mise en terrasses, témoin de contraintes édaphiques, hydriques, démographiques, techniques mais aussi culturelles et politiques à la culture dans les terroirs de pentes. Qu’elles traduisent la lutte contre l’érosion pour l’autonomie alimentaire, l’affirmation d’un pouvoir pendant ou après les colonisations, ou des visées développementalistes par grands projets, les terrasses sont des objets situés historiquement, politiquement et géographiquement. L’approche par leur seule dimension technique ou traditionnelle se montre insuffisante et nécessite de réfléchir à leur articulation aux systèmes ruraux dans lesquels elles s’insèrent. Notre article tente une synthèse à partir de la bibliographie et d’expériences de terrain variées visant à faire ressortir la particularité de la situation africaine et la complexité d’un objet qu’on désigne sous le simple vocable « terrasse ».