bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiative Transfer Modeling of an SN 1987A Light Echo—AT 2019xis
Authors: Ding Jiachen , Wang Lifan , Brown Peter , Yang Ping 
Published: September 2021

Abstract
We use a Monte Carlo radiative transfer model (MCRTM) to simulate the UBVRI light curves, images, and linear polarization of a light echo from supernova SN 1987A in the Large Magellanic Cloud (LMC) using various dust cloud shapes, sizes, and optical properties. We compare the theoretical simulations to the observations of AT 2019xis, a light echo detected at a large angular distance (4.′05) from SN 1987A. We estimate the size and optical thickness of the dust cloud based on the simulation results and the observations of the Optical Gravitational Lensing Experiment (OGLE-IV) Transient Detection System (OTDS) I-band light curve. The mass of the dust cloud is calculated using the estimated size, optical thickness, and extinction coefficient. If the dust cloud is assumed to correspond to a gas-to-dust ratio of 300, the total mass of the dust cloud is approximately 7.8–9.3 M
⊙. Based on these theoretical models, we show that the morphological shapes of the light echoes in the wavelength range of or shorter than the U band to be very different from those in the longer wavelength bands, and the difference carries important information on the early UV radiation of SN 1987A.
Free Energy Sources in Current Sheets Formed in Collisionless Plasma Turbulence
Authors: Jain Neeraj , Büchner Jörg , Comişel Horia , Motschmann Uwe 
Published: September 2021

Abstract
Collisionless dissipation of macroscopic energy into heat is an unsolved problem of space and astrophysical plasmas, e.g., solar wind and Earth’s magnetosheath. The most viable process under consideration is the turbulent cascade of macroscopic energy to kinetic scales where collisionless plasma processes dissipate the energy. Space observations and numerical simulations show the formation of kinetic scale current sheets in turbulent plasmas. Instabilities in these current sheets (CS) can provide collisionless dissipation and influence the turbulence. Spatial gradients of physical quantities and non-Maxwellian velocity distribution functions provide the free energy sources for CS plasma instabilities. To determine the free energy sources provided by the spatial gradients of plasma density and electron/ion bulk velocities in CS formed in collisionless turbulent plasmas with an external magnetic field
B

0, we carried out two-dimensional particle-in-cell-hybrid simulations and interpret the results within the limitations of the simulation model. We found that ion-scale CS in a collisionless turbulent plasma are formed primarily by electron shear flows, i.e., electron bulk velocity inside CS is much larger than ion bulk velocity while the density variations through the CS are relatively small (<10%). The electron bulk velocity and, thus, the current density inside the sheets are directed mainly parallel to
B

0. The shear in the perpendicular electron and ion bulk velocities generates parallel electron and ion flow vorticities. Inside CS, parallel electron flow vorticity exceeds the parallel ion flow vorticity, changes sign around the CS centers, and peaks near the CS edges. An ion temperature anisotropy develops near CS during the CS formation. It has a positive correlation with the parallel ion and electron flow vorticities. Theoretical estimates support the simulation results.
Detailed Abundances of Planet-hosting Open Clusters. The Praesepe (Beehive) Cluster*
Authors: Vejar George , Schuler Simon C. , Stassun Keivan G. 
Published: September 2021

Abstract
It is not yet fully understood how planet formation affects the properties of host stars, in or out of a cluster; however, abundance trends can help us understand this process. We present a detailed chemical abundance analysis of six stars in Praesepe, a planet-hosting open cluster. Pr0201 is known to host a close-in (period of 4.4 days) giant planet (mass of 0.54 M
J), while the other five cluster members in our sample (Pr0133, Pr0081, Pr0208, Pr0051, and Pr0076) have no detected planets according to measurements of radial velocity. Using high-resolution echelle spectra with high signal-to-noise ratio obtained with Keck/HIRES and a novel approach to measurements of equivalent width (XSpect-EW), we derived abundances of up to 20 elements spanning a range of condensation temperatures (T
C). We find a mean cluster metallicity of [Fe/H] = +0.21 ± 0.02 dex, in agreement with most previous determinations. We find most of our elements show an [X/Fe] scatter of ∼0.02–0.03 dex and conclude that our stellar sample is chemically homogeneous. The T
C slope for the cluster mean abundances is consistent with zero and none of the stars in our sample exhibit individually a statistically significant T
C slope. Using a planet engulfment model, we find that the planet host, Pr0201, shows no evidence of significant enrichment in its refractory elements when compared to the cluster mean that would be consistent with a planetary accretion scenario.
Mid-infrared Period–Luminosity Relations for Miras in the Large Magellanic Cloud
Authors: Iwanek Patryk , Soszyński Igor , Kozłowski Szymon 
Published: September 2021

Abstract
We present the mid-infrared (mid-IR) period–luminosity relations (PLRs) using over 1000 Mira variables in the Large Magellanic Cloud, for the four Wide-field Infrared Survey Explorer and the four Spitzer bands. These PLRs cover a mid-IR wavelength range from 3.4–22 μm and are presented separately for the oxygen-rich (O-rich) and carbon-rich (C-rich) Miras. These relations can be used to measure distances to individual O-rich and/or C-rich Mira stars with an accuracy of 5% and 12%, respectively. They are the most accurate Mira PLRs in the mid-IR to date.
Connecting the Low to the High Corona: A Method to Isolate Transients in STEREO/COR1 Images
Authors: Alzate Nathalia , Morgan Huw , Viall Nicholeen , Vourlidas Angelos 
Published: September 2021

Abstract
We present a method that isolates time-varying components from coronagraph and extreme ultraviolet images, allowing substreamer transients propagating within streamers to be tracked from the low to the high corona. The method uses a temporal bandpass filter with a transmission bandwidth of ∼2.5–10 hr that suppresses both high- and low-frequency variations in observations made by the STEREO/SECCHI suite. We demonstrate that this method proves crucial in linking features in the low corona, where the magnetic field is highly nonradial, to their counterparts in the high corona, where the magnetic field follows a radial path, through the COR1 instrument. We also apply our method to observations by the COR2 and EUVI instruments on board SECCHI and produce height–time profiles that reveal small density enhancements, associated with helmet streamers propagating from ∼1.2 R
⊙ out to beyond 5 R
⊙. Our processing method reveals that these features are common during the period of solar minimum in this study. The features recur on timescales of hours, originate very close to the Sun, and remain coherent out into interplanetary space. We measure the speed of the features and classify them as slow (a few to tens of kilometers per second) or fast (∼100 km s−1). Both types of features serve as an observable tracer of a variable component of the slow solar wind to its source regions. Our methodology helps overcome the difficulties in tracking small-scale features through COR1. As a result, it proves successful in measuring the connectivity between the low and high corona and in measuring the velocities of small-scale features.
Electron Acceleration at Rippled Low-mach-number Shocks in High-beta Collisionless Cosmic Plasmas
Authors: Kobzar Oleh , Niemiec Jacek , Amano Takanobu , Hoshino Masahiro , Matsukiyo Shuichi , Matsumoto Yosuke , Pohl Martin 
Published: September 2021

Abstract
Using large-scale fully kinetic two-dimensional particle-in-cell simulations, we investigate the effects of shock rippling on electron acceleration at low-Mach-number shocks propagating in high-β plasmas, in application to merger shocks in galaxy clusters. We find that the electron-acceleration rate increases considerably when the rippling modes appear. The main acceleration mechanism is stochastic shock-drift acceleration, in which electrons are confined at the shock by pitch-angle scattering off turbulence and gain energy from the motional electric field. The presence of multiscale magnetic turbulence at the shock transition and the region immediately behind the main shock overshoot is essential for electron energization. Wide-energy non-thermal electron distributions are formed both upstream and downstream of the shock. The maximum energy of the electrons is sufficient for their injection into diffusive shock acceleration. We show for the first time that the downstream electron spectrum has a power-law form with index p ≈ 2.5, in agreement with observations.
Broadband Variability Study of Maxi J1631-479 in Its Hard-intermediate State Observed with Insight-HXMT
Authors: Bu Q. C. , Zhang S. N. , Santangelo A. , Belloni T. M. , Zhang L. , Qu J. L. , Tao L. , Huang Y. , Ma X. , Li Z. S. , Zhang S. , Chen L. ,   and the Insight-HMXT collaboration:, Cai C. , Cao X. L. , Chang Z. , Chen T. X. , Chen Y. , Chen Y. P. , Cui W. W. , Du Y. Y. , Gao G. H. , Gao H. , Ge M. Y. , Gu Y. D. , Guan J. , Guo C. C. , Han D. W. , Huo J. , Jia S. M. , Jiang W. C. , Jin J. , Kong L. D. , Li B. , Li C. K. , Li G. , Li T. P. , Li W. , Li X. , Li X. B. , Li X. F. , Li Z. W. , Liang X. H. , Liao J. Y. , Liu C. Z. , Liu H. X. , Liu H. W. , Liu X. J. , Lu F. J. , Lu X. F. , Luo Q. , Luo T. , Ma R. C. , Meng B. , Nang Y. , Nie J. Y. , Ou G. , Sai N. , Song L. M. , Song X. Y. , Sun L. , Tan Y. , Tuo Y. L. , Wang C. , Wang L. J. , Wang P. J. , Wang W. S. , Wang Y. S. , Wen X. Y. , Wu B. Y. , Wu B. B. , Wu M. , Xiao G. C. , Xiao S. , Xiong S. L. , Xu Y. P. , Yang S. , Yang Y. J. , Yi Q. B. , Yin Q. Q. , You Y. , Zhang F. , Zhang H. M. , Zhang J. , Zhang P. , Zhang W. C. , Zhang W. , Zhang Y. F. , Zhang Y. H. , Zhao H. S. , Zhao X. F. , Zheng S. J. , Zhou D. K. 
Published: September 2021

Abstract
We report the energy-resolved broadband timing analysis of the black hole X-ray transient MAXI J1631-479 during its 2019 outburst from February 11 to April 9, using data from the Insight−Hard X-ray Modulation Telescope (Insight-HXMT), which caught the source from its hard-intermediate state to the soft state. Thanks to the large effective area of Insight-HXMT at high energies, we are able to present the energy dependence of fast variability up to ∼100 keV. Type-C quasi-periodic oscillations (QPOs) with a frequency varying between 4.9 and 6.5 Hz are observed in the 1–100 keV energy band. While the QPO fractional rms increases with photon energy from 1 keV to ∼10 keV and remains more or less constant from ∼10 keV to ∼100 keV, the rms of the flat-top noise first increases from 1 keV to ∼8 keV and then drops to less than 0.1% above ∼30 keV. We suggest that the disappearance of the broadband variability above 30 keV could be caused by the nonthermal acceleration in the Comptonizing plasma. At the same time, the QPOs could be produced by the precession of either a small-scale jet or a hot inner flow model.
Effect of Dust Rotational Disruption by Radiative Torques and Implications for the F-corona Decrease Revealed by the Parker Solar Probe
Authors: Hoang Thiem , Lazarian Alex , Lee Hyeseung , Cho Kyungsuk , Gu Pin-Gao , Ng Chi-Hang 
Published: September 2021

Abstract
The first-year results from the Parker Solar Probe (PSP) reveal a gradual decrease of F-coronal dust from distances of D = 0.166–0.336 au (or the inner elongations of ∼9.22–18.69 R
⊙) to the Sun. Such an F-corona decrease cannot be explained by the dust sublimation scenario of the popular silicate composition that implies a dust-free boundary zone at heliocentric radius R ≲ 4–5 R
⊙, but it may be explained by appealing to various dust compositions with different sublimation fronts. In this paper, we present an additional explanation for the F-corona decrease using our newly introduced mechanism of dust destruction, the so-called Radiative Torque Disruption (RATD) mechanism. We demonstrate that the RATD rapidly breaks large grains into nanoparticles so that they can be efficiently destroyed by nonthermal sputtering induced by the bombardment of energetic protons from slow solar winds, which extends the dust-free zone established by thermal sublimation to R
dfz ∼ 8 R
⊙. Beyond this extended dust-free zone, we find that the dust mass decreases gradually from R ∼ 42 R
⊙ toward the Sun due to partial removal of nanodust by nonthermal sputtering. The joint effect of the RATD and nonthermal sputtering can successfully reproduce the gradual decrease of the F-corona between 19 and 9 R
⊙ observed by the PSP. Finally, the RATD mechanism can efficiently produce nanoparticles usually observed in the inner solar system.
The Role of Complex Ionized Absorbers in the Soft X-Ray Spectra of Intermediate Polars
Authors: Islam Nazma , Mukai Koji 
Published: September 2021

Abstract
In magnetic cataclysmic variables (mCVs), X-ray radiation originates from a shock-heated, multi-temperature plasma in the post-shock region near the white dwarf’s surface. These X-rays are modified by a complex distribution of absorbers in the pre-shock region. The presence of photoionized lines and warm absorber features in the soft X-ray spectra of these mCVs suggests that these absorbers are ionized. We developed the ionized complex absorber model zxipab, which is represented by a power-law distribution of ionized absorbers in the pre-shock flow. Using the ionized absorber model zxipab along with a cooling flow model with a reflection component, we model the broadband Chandra/High-Energy Transmission Grating (HETG) and Nuclear Spectroscopic Telescope Array (NuSTAR) spectra of two intermediate polars (IPs): NY Lup and V1223 Sgr. We find that this model describes well many of the H- and He-like emission lines from medium-Z elements, which arise from a collisionally excited plasma. However the model fails to account for some of the He-like triplets from the medium-Z elements, which points toward their photoionized origin. We do not find compelling evidence for a blackbody component to model the soft excess seen in the residuals of the Chandra/HETG spectra, which could be due to uncertainties in the estimation of the interstellar absorption of these sources using the Chandra/HETG data and/or excess fluxes seen in some photoionized emission lines which are not accounted for by the cooling flow model. We describe the implications of this model with respect to the geometry of the pre-shock region for these two IPs.
Fast Radio Bursts and Their High-energy Counterparts from Magnetar Magnetospheres
Authors: Yang Yuan-Pei , Zhang Bing 
Published: September 2021

Abstract
The recent discovery of a Galactic fast radio burst (FRB) occurring simultaneously with an X-ray burst (XRB) from the Galactic magnetar SGR J1935+2154 implies that at least some FRBs arise from magnetar activities. We propose that FRBs are triggered by crust fracturing of magnetars, with the burst event rate depending on the magnetic field strength in the crust. Since the crust-fracturing rate is relatively higher in polar regions, FRBs are more likely to be triggered near the directions of multipolar magnetic poles. Crust fracturing produces Alfvén waves, forming a charge-starved region in the magnetosphere and leading to nonstationary pair plasma discharges. An FRB is produced by coherent plasma radiation due to nonuniform pair production across magnetic field lines. Meanwhile, the FRB-associated XRB is produced by the rapid relaxation of the external magnetic field lines. In this picture, the sharp-peak hard X-ray component in association with FRB 200428 is from a region between adjacent trapped fireballs, and its spectrum with a high cutoff energy is attributed to resonant Compton scattering. The persistent X-ray emission is from a hot spot heated by the magnetospheric activities, and its temperature evolution is dominated by magnetar surface cooling. Within this picture, magnetars with stronger fields tend to produce brighter and more frequent repeated bursts.
„Festzertrümmerung“. Literaturpreise und Ritualbrüche
Authors: Braun Michael 
Published: September 2021

Chaque année, plus de 700 prix littéraires sont décernés en Allemagne. Ils sont des repères dans le milieu littéraire, mais font aussi l’objet de critiques (on leur reproche de représenter une promotion excessive, une instrumentalisation politique, une entrave à la liberté artistique). Un prix littéraire peut « faire » un auteur (prix Büchner pour Durs Grünbein en 1995, dernière sélection du prix du livre allemand 2015 pour Daniel Kehlmann) et rendre un genre littéraire plus populaire (prix Büchner à Elke Erb et prix Nobel à Louise Glück en 2020). L’article examine, dans une perspective de théorie des rituels, les prix littéraires dans la culture de la présence d’un « large présent » (Gumbrecht) : comment ils sont représentés dans le récit satirique ( Preisverleihung , 1972, de Günter de Bruyn, Das bin doch ich , 2007 de Thomas Glavinic) et comment ils sont mis en scène comme ruptures rituelles dans les discours de remise de prix ( Meine Preise , 2009, de Thomas Bernhard, Verunstaltung durch Veranstaltung , 1993, de Hans Magnus Enzensberger, discours de réception, par Martin Walser, du prix de la Paix des Libraires allemands en 1998). Les ruptures rituelles dans les cérémonies de remise de prix littéraires tant fictives que réelles instaurent des frontières dans le champ de la littérature contemporaine.
Anita Brookner and the Servants: Power Struggles and British Jewish Domestic Spaces in her Early Fiction
Authors: Stetz Margaret D. 
Published: September 2021

Quoique le service domestique ait disparu en tant qu’institution après la Seconde Guerre mondiale, il n’en reste pas moins un élément majeur dans les romans qu’Anita Brookner publia au début des années 1980, tout comme dans l’œuvre d’avant-guerre de Virginia Woolf. Cependant, le rôle joué par le personnel de maison, notamment féminin, chez Brookner n’est pas une survivance uniforme du passé, ni le signe d’une forme de nostalgie envers les hiérarchies sociales de l’époque de Woolf, mais plutôt un rôle ambigu, instable et déconcertant. Maîtres et serviteurs sont liés par des relations d’hostilité et de dévouement, mais aussi d’amour, de dépendance et de tensions inter-générationnelles qui reflètent les dynamiques familiales compliquées dans lesquelles évoluent les protagonistes de Brookner. Compliquant encore les relations entre ces serviteurs et leurs maîtresses, dans la fiction, se trouve l’identité juive de ces dernières. Brookner déploie tout un réseau métaphorique autour de l’occupation et du confinement d’une part, et du déplacement d’autre part, qui permet de lire, derrière les conflits de pouvoir entre maîtres et serviteurs pour le contrôle de l’espace domestique, de nombreuses allusions à la situation historique des Juifs européens au xx e siècle.
Analyse multi-niveau de l’effet du climat diversité sur l’identification organisationnelle – Importance de la perception d’« insider »
Authors: Cachat-Rosset Gaëlle , Klarsfeld Alain , Carillo Kevin 
Published: September 2021

Un climat pro-diversité serait primordial pour bénéficier des effets positifs de la diversité croissante des équipes de travail (Cox, 1993). Parmi ses effets positifs escomptés, figure le renforcement des états affectifs des salariés, et notamment leur identification à l’organisation. Nous proposons dans cet article d’apprécier l’influence de la perception de climat diversité de l’unité de travail sur l’identification organisationnelle, relation encore peu explorée et aux résultats mitigés, a fortiori dans le contexte français, dans lequel le climat diversité n’a fait l’objet d’aucune recherche empirique. Nous conceptualisons le climat diversité en 3 dimensions que sont l’intentionnalité, la programmation et la praxis (Cachat-Rosset et al ., 2019), répondant ainsi aux incohérences théoriques, conceptuelles et opérationnelles récemment soulevées à propos de ce concept (Cachat-Rosset et al ., 2019 ; McKay & Avery, 2015). S’appuyant sur une étude administrée auprès de salariés français dans 40 unités de travail, nos résultats montrent que la perception d’un climat diversité au sein de l’unité de travail influence positivement et significativement la perception d’« insider » et l’identification organisationnelle, et qu’il y a médiation de la perception d’« insider » dans la relation climat diversité - identification organisationnelle.
La surveillance a-t-elle une couleur politique ? Cercles de vigilance, capital social et compétition municipale dans des espaces périurbains en France
Authors: Gardenier Matthijs 
Published: September 2021

Depuis 2011 et la circulaire Guéant sur la « participation citoyenne », nous assistons en France au développement des Voisins Vigilants , sur le modèle des neighbourhood watches américaines et britanniques. Le concept est simple : il s’agit d’organiser un réseau de voisin·es qui avertiraient la police lorsque des actes délictueux seraient commis dans leur quartier. Situés principalement dans le périurbain résidentiel, ces cercles cibleraient principalement les cambriolages, dans des quartiers où il y a peu de monde pendant la journée. Les Voisins Vigilants n’auraient pas vocation à intervenir contre des délits, mais à mettre en place une surveillance, matérialisée par le logo du mouvement, un œil grand ouvert sur fond jaune. Au cours d’une enquête de terrain dans sept communautés différentes, nous observons que ces réseaux s’inscrivent dans la perspective de créer un espace social perçu par les participant·es comme sécurisé, pouvant devenir un outil d’affirmation de l’entre-soi. Cette vision partagée sera aussi pour certains acteurs l’occasion d’accumuler un capital social leur permettant de s’intégrer au jeu électoral des localités où se développent ces réseaux de surveillance.
Démocratiser le fusil. L’imagination composite d’une citoyenneté coercitive en Ouganda
Authors: Brisset-Foucault Florence 
Published: September 2021

Lorsqu’elles prennent le pouvoir en Ouganda en 1986, les nouvelles élites politiques du Mouvement de résistance nationale (NRM) promeuvent un modèle de citoyenneté refondée au nom duquel les citoyen·nes doivent prendre en charge leur sécurité. Cet article reconstitue l’épaisseur sociale et historique des conceptions du civisme et de l’appartenance qui s’expriment à travers la participation à l’ordre en articulant plusieurs échelles : transnationale, nationale, régionale et locale. Si ces dispositifs ont été très critiqués du fait de la violence dont ils sont la source, ils peuvent aussi être le support de la production de communautés morales. Loin d’être antagoniques, les conceptions de l’ordre et de la citoyenneté exprimées et produites par le bas et par le haut à travers la participation à l’ordre se rejoignent dans l’élaboration d’un idéal du village comme berceau de la production de personnes civiques.
Retour de la haute intensité : comment résoudre le dilemme entre masse et technologie ?
Authors: Toutain Xavier 
Published: September 2021

Avec la perspective du retour de la haute intensité, et alors que l’actualisation stratégique a confirmé la pertinence d’un modèle complet d’armée, une remontée en puissance s’impose : il s’agit de pouvoir agir avec succès dans un environnement contesté en maîtrisant l’attrition, et d’opérer un effet d’entraînement sur nos partenaires. Retrouver une masse critique suffisante, sans renoncer aux technologies de rupture, n’est pas un objectif irréaliste. D’abord, le rendement de la masse opérationnelle peut être optimisé. Ensuite, des marges de manœuvre peuvent être trouvées, avec une approche équilibrée de la technologie, le retour à une certaine différenciation capacitaire, et une recherche de plus grandes synergies à l’international.