bluuebunny/crossref_metadata_2025_split huggingface dataset:
NORMATIVE LEGAL AND METHODOLOGICAL REGULATION IN THE FIELD OF VOLUNTARY FIRE SERVICE ACTIVITIES
Authors: Перегудова Наталья Васильевна , Кононко Павел Павлович , Гаврюшенко Виктория Павловна , Илларионова Надежда Михайловна 
Published: April 2021

В статье проведен обзор нормативных правовых документов, регулирующих деятельность подразделений МЧС России по взаимодействию с добровольными пожарными (волонтерами). Анализ актуального законодательства Российской Федерации позволяет разобраться в вопросах статуса добровольцев и волонтеров, а также раскрыть организационные аспекты привлечения добровольных пожарных (волонтеров) и добровольческих (волонтерских) организаций к ликвидации последствий чрезвычайных ситуаций в Российской Федерации.
The article provides an overview of the normative legal documents regulating the activities of EMERCOM of Russia divisions regarding interaction with volunteer firefighters (volunteers). The analysis of the current legislation of the Russian Federation enables to investigate the issues of the status of voluntary servants and volunteers, as well as to reveal the organizational aspects concerning involvement of volunteer firefighters (volunteers) and volunteer organizations during elimination of emergencies in the Russian Federation.
The VLA Frontier Fields Survey: Deep, High-resolution Radio Imaging of the MACS Lensing Clusters at 3 and 6 GHz
Authors: Heywood I. , Murphy E. J. , Jiménez-Andrade E. F. , Armus L. , Cotton W. D. , DeCoursey C. , Dickinson M. , Lazio T. J. W. , Momjian E. , Penner K. , Smail I. , Smirnov O. M. 
Published: April 2021

Abstract
The Frontier Fields project is an observational campaign targeting six galaxy clusters, with the intention of using the magnification provided by gravitational lensing to study galaxies that are extremely faint or distant. We used the Karl G. Jansky Very Large Array (VLA) at 3 and 6 GHz to observe three Frontier Fields: MACS J0416.1−2403 (z = 0.396), MACS J0717.5+3745 (z = 0.545), and MACS J1149.5+2223 (z = 0.543). The images reach noise levels of ∼1 μJy beam−1 with subarcsecond resolution (∼2.5 kpc at z = 3), providing a high-resolution view of high-z star-forming galaxies that is unbiased by dust obscuration. We generate dual-frequency continuum images at two different resolutions per band, per cluster, and derive catalogs totaling 1966 compact radio sources. Components within the areas of Hubble Space Telescope and Subaru observations are cross-matched, providing host galaxy identifications for 1296 of them. We detect 13 moderately lensed (2.1 < μ < 6.5) sources, one of which has a demagnified peak brightness of 0.9 μJy beam−1, making it a candidate for the faintest radio source ever detected. There are 66 radio sources exhibiting complex morphologies, and 58 of these have host galaxy identifications. We reveal that MACS J1149.5+2223 is not a cluster with a double relic, as the western candidate relic is resolved as a double-lobed radio galaxy associated with a foreground elliptical at z = 0.24. The VLA Frontier Fields project is a public legacy survey. The image and catalog products from this work are freely available.
Axisymmetric Radiative Transfer Models of Kilonovae
Authors: Korobkin Oleg , Wollaeger Ryan T. , Fryer Christopher L. , Hungerford Aimee L. , Rosswog Stephan , Fontes Christopher J. , Mumpower Matthew R. , Chase Eve A. , Even Wesley P. , Miller Jonah , Misch G. Wendell , Lippuner Jonas 
Published: April 2021

Abstract
The detailed observations of GW170817 proved for the first time directly that neutron star mergers are a major production site of heavy elements. The observations could be fit by a number of simulations that qualitatively agree, but can quantitatively differ (e.g., in total r-process mass) by an order of magnitude. We categorize kilonova ejecta into several typical morphologies motivated by numerical simulations, and apply a radiative transfer Monte Carlo code to study how the geometric distribution of the ejecta shapes the emitted radiation. We find major impacts on both spectra and light curves. The peak bolometric luminosity can vary by two orders of magnitude and the timing of its peak by a factor of five. These findings provide the crucial implication that the ejecta masses inferred from observations around the peak brightness are uncertain by at least an order of magnitude. Mixed two-component models with lanthanide-rich ejecta are particularly sensitive to geometric distribution. A subset of mixed models shows very strong viewing angle dependence due to lanthanide “curtaining,” which persists even if the relative mass of lanthanide-rich component is small. The angular dependence is weak in the rest of our models, but different geometric combinations of the two components lead to a highly diverse set of light curves. We identify geometry-dependent P Cygni features in late spectra that directly map out strong lines in the simulated opacity of neodymium, which can help to constrain the ejecta geometry and to directly probe the r-process abundances.
High Metal Content of Highly Accreting Quasars
Authors: Śniegowska Marzena , Marziani Paola , Czerny Bożena , Panda Swayamtrupta , Martínez-Aldama Mary Loli , del Olmo Ascensión , D’Onofrio Mauro 
Published: April 2021

Abstract
We present an analysis of UV spectra of 13 quasars believed to belong to extreme Population A (xA) quasars, aimed at the estimation of the chemical abundances of the broad-line-emitting gas. Metallicity estimates for the broad-line-emitting gas of quasars are subject to a number of caveats; xA sources with the strongest Fe ii emission offer several advantages with respect to the quasar general population, as their optical and UV emission lines can be interpreted as the sum of a low-ionization component roughly at quasar rest frame (from virialized gas), plus a blueshifted excess (a disk wind), in different physical conditions. Capitalizing on these results, we analyze the component at rest frame and the blueshifted one, exploiting the dependence of several intensity line ratios on metallicity Z. We find that the validity of intensity line ratios as metallicity indicators depends on the physical conditions. We apply the measured diagnostic ratios to estimate the physical properties of sources such as density, ionization, and metallicity of the gas. Our results confirm that the two regions (the low-ionization component and the blueshifted excess) of different dynamical conditions also show different physical conditions and suggest metallicity values that are high, and probably the highest along the quasar main sequence, with Z ∼ 20−50 Z
⊙, if the solar abundance ratios can be assumed constant. We found some evidence of an overabundance of aluminum with respect to carbon, possibly due to selective enrichment of the broad-line-emitting gas by supernova ejecta.
A Homogeneous Comparison between the Chemical Composition of the Large Magellanic Cloud and the Sagittarius Dwarf Galaxy*
Authors: Minelli A. , Mucciarelli A. , Romano D. , Bellazzini M. , Origlia L. , Ferraro F. R. 
Published: April 2021

Abstract
Similarities in the chemical composition of two of the closest Milky Way satellites, namely, the Large Magellanic Cloud (LMC) and the Sagittarius (Sgr) dwarf galaxy, have been proposed in the literature, suggesting similar chemical enrichment histories between the two galaxies. This proposition, however, rests on different abundance analyses, which likely introduce various systematics that hamper a fair comparison among the different data sets. In order to bypass this issue (and highlight real similarities and differences between their abundance patterns), we present a homogeneous chemical analysis of 30 giant stars in the LMC, 14 giant stars in Sgr, and 14 giants in the Milky Way, based on high-resolution spectra taken with the spectrograph UVES-FLAMES. The LMC and Sgr stars, in the considered metallicity range ([Fe/H] > −1.1 dex), show very similar abundance ratios for almost all the elements, with differences only in the heavy s-process elements Ba, La, and Nd, suggesting a different contribution by asymptotic giant branch stars. On the other hand, the two galaxies have chemical patterns clearly different from those measured in the Galactic stars, especially for the elements produced by massive stars. This finding suggests that the massive stars contributed less to the chemical enrichment of these galaxies with respect to the Milky Way. The derived abundances support similar chemical enrichment histories for the LMC and Sgr.
Physical Characteristics of Unstructured Coronal Clouds
Authors: Asgari-Targhi M. , Golub L. , Hahn M. , Karna N. , Savin D. W. 
Published: April 2021

Abstract
Active regions in the inner solar corona, when observed in X-ray emission, consist of bright, hot loops surrounded by unstructured clouds. The emission from the clouds extends to a height of ≈4–5 × 104 km at temperatures of ≈2–3 MK. These “hot clouds” are variable, but persist for many days and do not appear to connect directly to the active region streamers or other large-scale structures observed higher in the corona. We present an observational analysis of these diffuse structures to establish basic plasma parameters such as magnetic field strength, particle density, and temperature. The values of β, the ratio of the plasma pressure to the magnetic field pressure, were found to be generally less than unity, though often approaching unity in the upper portions of the active region, where the hot clouds are located. The magnetic field may therefore only partially confine these regions and inhibit flare-like instabilities that could otherwise be driven by gradients of plasma pressure and current density.
Gas Infalling Motions in the Envelopes of Very Low Luminosity Objects
Authors: Kim Mi-Ryang , Lee Chang Won , Maheswar G. , Myers Philip C. , Kim Gwanjeong 
Published: April 2021

Abstract
We present the results of a single-dish survey toward 95 very low luminosity objects (VeLLOs) in optically thick (HCN 1−0) and thin (N2H+ 1−0) lines performed for the purpose of understanding the physical processes of inward motions in the envelopes of the VeLLOs and characterizing their true nature. The normalized velocity differences (

δ

V

HCN

) between the peak velocities of the two lines were derived for 41 VeLLOs detected in both lines. The δ
V distribution of these VeLLOs is found to be significantly skewed to the blue, indicating the dominance of infalling motions in their envelopes. The infall speeds were derived for 15 infall candidates by using the HILL5 radiative transfer model. The speeds were in the range of 0.03−0.3 km s−1, with a median value of 0.16 km s−1, consistent with the gravitational freefall speeds from pressure-free envelopes. The mass infall rates calculated from the infall speeds are mostly of the order of 10−6
M
⊙ yr−1, with a median value of (3.4 ± 1.5) × 10−6
M
⊙ yr−1. These are found to be also consistent with the values predicted with the inside-out collapse model and show a fairly good correlation with the internal luminosities of the VeLLOs. This again indicates that the infall motions observed toward the VeLLOs are likely to be due to the gravitational infall motions in their envelopes. Our study suggests that most of the VeLLOs are potentially faint protostars, while two of the VeLLOs could possibly be proto−brown dwarf candidates.
The Nature of the Eccentric Double-lined Eclipsing Binary System KIC 2306740 with Kepler Space Photometry
Authors: Koçak D. , Yakut K. , Southworth J. , Eggleton P. P. , İçli T. , Tout C. A. , Bloemen S. 
Published: April 2021

Abstract
We present a detailed study of KIC 2306740, an eccentric double-lined eclipsing binary system. Kepler satellite data were combined with spectroscopic data obtained with the 4.2 m William Herschel Telescope (WHT). This allowed us to determine precise orbital and physical parameters of this relatively long period (P = 10.ͩ3) and slightly eccentric (e = 0.3) binary system. The physical parameters have been determined to be M
1 = 1.194 ± 0.008 M
⊙, M
2 = 1.078 ± 0.007 M
⊙, R
1 = 1.682 ± 0.004 R
⊙, R
2 = 1.226 ± 0.005 R
⊙, L
1 = 2.8 ± 0.4 L
⊙, L
2 = 1.8 ± 0.2 L
⊙, and orbital separation a = 26.20 ± 0.04 R
⊙ through simultaneous solutions of the Kepler light curves and WHT radial velocity data. Binarity effects were extracted from the light curve in order to study intrinsic variations in the residuals. Five significant and more than 100 combination frequencies were detected. We modeled the binary system assuming nonconservative evolution models with the Cambridge stars (twin) code, and we show the evolutionary tracks of the components in the

log
L
–
log
T

plane, the

log
R
–
log
M

plane, and the

log
P
–
age

plane for both spin and orbital periods together with eccentricity e and

log

R

1

. The model of the nonconservative processes in the code led the system to evolve to the observed system parameters in roughly 5.1 Gyr.
A Knee Point in the Rotation–Activity Scaling of Late-type Stars with a Connection to Dynamo Transitions
Authors: Lehtinen Jyri J. , Käpylä Maarit J. , Olspert Nigul , Spada Federico 
Published: April 2021

Abstract
The magnetic activity of late-type stars is correlated with their rotation rates. Up to a certain limit, stars with smaller Rossby numbers, defined as the rotation period divided by the convective turnover time, have higher activity. A more detailed look at this rotation–activity relation reveals that, rather than being a simple power-law relation, the activity scaling has a shallower slope for the low-Rossby stars than for the high-Rossby ones. We find that, for the chromospheric Ca II H&K activity, this scaling relation is well modeled by a broken two-piece power law. Furthermore, the knee point of the relation coincides with the axisymmetry to nonaxisymmetry transition seen in both the spot activity and surface magnetic field configuration of active stars. We interpret this knee point as a dynamo transition between dominating axi- and nonaxisymmetric dynamo regimes with a different dependence on rotation and discuss this hypothesis in the light of current numerical dynamo models.
On the Beam Filling Factors of Molecular Clouds
Authors: Yan Qing-Zeng , Yang Ji , Yang Su  , Sun Yan , Wang Chen 
Published: April 2021

Abstract
Imaging surveys of CO and other molecular transition lines are fundamental to measuring the large-scale distribution of molecular gas in the Milky Way. Due to finite angular resolution and sensitivity, however, observational effects are inevitable in the surveys, but few studies are available on the extent of uncertainties involved. The purpose of this work is to investigate the dependence of observations on angular resolution (beam sizes), sensitivity (noise levels), distances, and molecular tracers. To this end, we use high-quality CO images of a large-scale region (258 < l < 497 and ∣b∣ < 5°) mapped by the Milky Way Imaging Scroll Painting (MWISP) survey as a benchmark to simulate observations with larger beam sizes and higher noise levels, deriving corresponding beam filling and sensitivity clip factors. The sensitivity clip factor is defined to be the completeness of observed flux. Taking the entire image as a whole object, we found that 12CO has the largest beam filling and sensitivity clip factors and C18O has the lowest. For molecular cloud samples extracted from images, the beam filling factor can be described by a characteristic size, l
1/4 = 0.762 (in beam size), at which the beam filling factor is approximately 1/4. The sensitivity clip factor shows a similar relationship but is more correlated with the mean voxel signal-to-noise ratio of molecular clouds. This result may serve as a practical reference on beam filling and sensitivity clip factors in further analyses of the MWISP data and other observations.
Backstreaming Pickup Ions
Authors: Gedalin Michael , Pogorelov Nikolai V. , Roytershteyn Vadim 
Published: April 2021

Abstract
Ions that are reflected at the shock front and escape back into the upstream region can play the role of ions that start to be accelerated by a diffusive shock acceleration mechanism. Backstreaming ions have been shown to be generated from a superthermal tail of the solar wind at sufficiently high upstream temperatures. The number of such ions was found to be low and they were not found at shock angles exceeding 50°. The mechanism of production is multiple reflection when an ion changes the direction of motion inside the ramp for the first time, due to the cross-shock potential. Since pickup ions (PUIs) constitute a strongly superthermal population of protons a substantially stronger production of backstreaming PUIs can be expected. We study the reflection of PUIs in a planar stationary shock front using test particle analysis. The used model is inspired by the observed profile of the termination shock. The influence of magnetic compression, the shock angle, and the overshoot are analyzed. It is found that generation of backstreaming PUIs in this shock is substantially more efficient than the generation of backstreaming protons from thermal solar wind. The fraction of backstreaming PUIs rapidly increases with the increase of magnetic compression and the decrease of the shock angle. Overshoot enhances production of backstreaming PUIs and allows it for larger shock angles. No backstreaming ions have been found for shock angles larger than 60°. The results of the test particle analysis are supported by full-particle simulations.
The VLA Frontier Field Survey: A Comparison of the Radio and UV/Optical Size of 0.3 ≲ z ≲ 3 Star-forming Galaxies
Authors: Jiménez-Andrade E. F. , Murphy E. J. , Heywood I. , Smail I. , Penner K. , Momjian E. , Dickinson M. , Armus L. , Lazio T. J. W. 
Published: April 2021

Abstract
To investigate the growth history of galaxies, we measure the rest-frame radio, ultraviolet (UV), and optical sizes of 98 radio-selected, star-forming galaxies (SFGs) distributed over 0.3 ≲ z ≲ 3 with a median stellar mass of

log
(

M

⋆

/

M

⊙

)
≈
10.4

. We compare the size of galaxy stellar disks, traced by rest-frame optical emission, relative to the overall extent of star formation activity that is traced by radio continuum emission. Galaxies in our sample are identified in three Hubble Frontier Fields: MACS J0416.1−2403, MACS J0717.5+3745, and MACS J1149.5+2223. Radio continuum sizes are derived from 3 and 6 GHz radio images (≲0.″6 resolution, ≈0.9 μJy beam−1 noise level) from the Karl G. Jansky Very Large Array. Rest-frame UV and optical sizes are derived using observations from the Hubble Space Telescope and the Advanced Camera for Surveys and Wide Field Camera 3 instruments. We find no clear dependence between the 3 GHz radio size and stellar mass of SFGs, which contrasts with the positive correlation between the UV/optical size and stellar mass of galaxies. Focusing on SFGs with

log
(

M

⋆

/

M

⊙

)
>
10

, we find that the radio/UV/optical emission tends to be more compact in galaxies with high star formation rates (≳100 M
⊙ yr−1), suggesting that a central, compact starburst (and/or an active galactic nucleus) resides in the most luminous galaxies of our sample. We also find that the physical radio/UV/optical size of radio-selected SFGs with log(M
⋆/M
⊙) > 10 increases by a factor of 1.5–2 from z ≈ 3 to z ≈ 0.3, yet the radio emission remains two to three times more compact than that from the UV/optical. These findings indicate that these massive, radio-selected SFGs at 0.3 ≲ z ≲ 3 tend to harbor centrally enhanced star formation activity relative to their outer disks.
La ville du quart d’heure
Authors: Paquot Thierry 
Published: April 2021

La récente communication de la ville de Paris autour de « la ville du quart d’heure », où toutes les commodités seraient accessibles en quinze minutes de marche, soulèvent la question des politiques temporelles de la ville : comment l’espace urbain doit-il être aménagé pour favoriser l’organisation quotidienne ?
Pas vraiment étranger, mais presque apatride
Authors: D. A. , Lévy-Vroelant Claire 
Published: April 2021

Claire Lévy-Vroelant a rencontré A.D. un peu par hasard. Une connaissance lui avait parlé de ce jeune homme qu’elle avait aidé au début des années 2000 dans le cadre du Réseau Éducation Sans Frontières, alors qu’il était apatride. Le contact pris, A.D. a bien voulu revenir sur son parcours.
À Mayotte, la mise à sac des quartiers pauvres
Authors: Gros Daniel 
Published: April 2021

Alors que l’opinion s’émouvait, en pleine trêve hivernale, de l’évacuation par la force de centaines de personnes sans abri qui tentaient d’occuper la place de la République à Paris, à Mayotte, le préfet multipliait, avec la même brutalité, les destructions de quartiers entiers. Mais, cette fois-ci, dans l’indifférence générale ou presque. Qu’elle soit visible ou dissimulée, la brutalité de l’État cible les mêmes victimes : les franges les plus pauvres d’une population indésirable.
1981, l’incendie de New Cross, un tournant dans l’histoire des Noirs britanniques
Authors: Abdallah Mogniss H. 
Published: April 2021

Dans la nuit du 17 au 18 janvier 1981, l’incendie d’une maison au 439 New Cross Road, dans le sud de Londres, provoque la mort de 13 jeunes Noirs et en blesse 27 autres. Qui a mis le feu ? On ne le sait toujours pas. À la suite d’une enquête inaboutie, la police est mise en cause pour son déni de toute motivation raciste. Le « New Cross Massacre » suscite un immense émoi et une mobilisation dans tout le pays, culminant avec le Black People’s Day of Action, qui rassemble 20 000 personnes. Quelques semaines après éclatent les émeutes de Brixton. Ces événements vont accélérer les changements pour la reconnaissance des communautés noires dans la société britannique.
Vous avez dit « entrepreneuriat » ?
Authors: Lettenhove Maïté Kervyn de , Lemaître Andreia 
Published: April 2021

L’article interroge la forme que prend, au Bénin, la réémergence du discours sur l’entrepreneuriat, en se penchant sur l’évolution de la figure de petit entrepreneur dans le discours – globalisé – des « partenaires du développement » et sur la manière dont la figure d’entrepreneur est acceptée et réinterprétée localement par les élites et les populations bénéficiaires des programmes de soutien à l’entrepreneuriat. À travers l’analyse d’entretiens et de discussions de groupe, nos résultats montrent que, bien que la désignation « entrepreneur » soit désormais largement adoptée par les populations locales, ce terme, en contre-pied des tendances récentes des politiques d’aide, est principalement associé à la sécurisation réussie du groupe domestique et à la création de travail pour autrui.
La formation à l’entrepreneuriat de soi dans l’université marocaine
Authors: Hanif Salwa , Sabri Rhita 
Published: April 2021

La formation à la culture entrepreneuriale qui est conçue, financée et dispensée par l’association Injaz Al-Maghrib est délivrée dans la quasi-totalité des établissements de l’enseignement supérieur public marocain. Nous considérons que l’État marocain se « décharge » ainsi de la formation aux compétences comportementales sur cette ONG, tout en conservant au sein des universités publiques la mission de la formation aux savoirs théoriques et/ou techniques. Une étude ethnographique, réalisée dans les espaces de cette association, nous montre le mécanisme de l’introduction et, à terme, de l’institutionnalisation de cette formation dans les universités marocaines et son rôle dans la reproduction de certaines structures sociales, et la formation de nouveaux citoyens moins revendicateurs vis-à-vis de l’État.
Penser la paix économique : au-delà de l’harmonie sociale, les conditions de pacification de l’économie
Authors: Ottaviani Fiona , Steiler Dominique 
Published: April 2021

Cet article propose une contribution théorique afin de penser la paix dans le champ de l’économie. Nous mettons en exergue que les conditions de pacification des relations socio-économiques demeurent en partie impensée par la discipline économique qui a pourtant consacré une part de ses analyses à la question de l’harmonie sociale. Codes JEL : A1, B13, B15, N01.