bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolution of Primordial Magnetic Fields during Large-scale Structure Formation
Authors: Mtchedlidze Salome , Domínguez-Fernández Paola , Du Xiaolong , Brandenburg Axel , Kahniashvili Tina , O’Sullivan Shane , Schmidt Wolfram , Brüggen Marcus 
Published: April 2022

Abstract
Primordial magnetic fields (PMFs) could explain the large-scale magnetic fields present in the universe. Inflation and phase transitions in the early universe could give rise to such fields with unique characteristics. We investigate the magnetohydrodynamic evolution of these magnetogenesis scenarios with cosmological simulations. We evolve inflation-generated magnetic fields either as (i) uniform (homogeneous) or as (ii) scale-invariant stochastic fields, and phase-transition-generated ones either as (iii) helical or as (iv) nonhelical fields from the radiation-dominated epoch. We find that the final distribution of magnetic fields in the simulated cosmic web shows a dependence on the initial strength and the topology of the seed field. Thus, the observed field configuration retains information on the initial conditions at the moment of the field generation. If detected, PMF observations would open a new window for indirect probes of the early universe. The differences between the competing models are revealed on the scale of galaxy clusters, bridges, as well as filaments and voids. The distinctive spectral evolution of different seed fields produces imprints on the correlation length today. We discuss how the differences between rotation measures from highly ionized regions can potentially be probed with forthcoming surveys.
EXORCISM: A Spectroscopic Survey of Young Eruptive Variables (EXor and Candidates)
Authors: Giannini T. , Giunta A. , Gangi M. , Carini R. , Lorenzetti D. , Antoniucci S. , Caratti o Garatti A. , Cassará L. , Nisini B. , Rossi A. , Testa V. , Vitali F. 
Published: April 2022

Abstract
We present an optical/near-IR survey of 11 variable young stars (EXors and EXor candidates) aimed at deriving and monitoring their accretion properties. About 30 optical and near-infrared spectra (

R
∼
1500
–
2000

) were collected between 2014 and 2019 with the Large Binocular Telescope (LBT). From the spectral analysis we have derived the accretion luminosity (L
acc ) and mass accretion rate (

M

̇

acc

), the visual extinction (A
V), the temperature and density of the permitted line formation region (T, n
H), and the signature of the outflowing matter. Two sources (ASASSN-13db and iPTF15afq) have been observed in outburst and quiescence, three during a high level of brightness (XZ Tau, PV Cep, and NY Ori), and the others in quiescence. These latter have L
acc and

M

̇

acc

in line with the values measured in classical T Tauri stars of similar mass. All sources observed more than once present L
acc and

M

̇

acc

variability. The most extreme case is ASASSN-13db, for which

M

̇

acc

decreases by two orders of magnitude from the outburst peak in 2015 to quiescence in 2017. Also, in NY Ori L
acc decreases by a factor 25 in one year. In 80% of the sample we detect the [O i] 6300 Å line, a tracer of mass loss. From the variability of the Hα/[O i] 6300 Å ratio, we conclude that mass accretion variations are larger than mass loss variations. From the analysis of the H i recombination lines, a correlation is suggested between the density of the line formation region, and the level of accretion activity of the source.
Supernova Remnants in M83 as Observed with MUSE
Authors: Long Knox S. , Blair William P. , Winkler P. Frank , Della Bruna Lorenza , Adamo Angela , McLeod Anna F. , Amram Phillippe 
Published: April 2022

Abstract
Here we describe a new study of the supernova remnants (SNRs) and SNR candidates in nearby face-on spiral galaxy M83, based primarily on MUSE integral field spectroscopy. Our revised catalog of SNR candidates in M83 has 366 objects, 81 of which are reported here for the first time. Of these, 229 lie within the MUSE observation region, 160 of which have spectra with [S ii]:Hα ratios exceeding 0.4, the value generally accepted as confirmation that an emission nebula is shock-heated. Combined with 51 SNR candidates outside the MUSE region with high [S ii]:Hα ratios, there are 211 spectroscopically confirmed SNRs in M83, the largest number of confirmed SNRs in any external galaxy. MUSE’s combination of relatively high spectral resolution and broad wavelength coverage has allowed us to explore two other properties of SNRs that could serve as the basis of future SNR searches. Specifically, most of the objects identified as SNRs on the basis of [S ii]:Hα ratios exhibit more velocity broadening and lower ratios of [S iii]:[S ii] emission than H ii regions. A search for nebulae with the very broad emission lines expected from young, rapidly expanding remnants revealed none, except for the previously identified B12-174a. The SNRs identified in M83 are, with few exceptions, middle-aged interstellar medium (ISM) dominated ones. Smaller-diameter candidates show a larger range of velocity broadening and a larger range of gas densities than the larger-diameter objects, as expected if the SNRs expanding into denser gas brighten and then fade from view at smaller diameters than those expanding into a more tenuous ISM.
A Possible 3 yr Quasi-periodic Oscillation in γ-Ray Emission from the FSRQ S5 1044+71
Authors: Wang G. G. , Cai J. T. , Fan J. H. 
Published: April 2022

Abstract
Variability is a typical observation feature of Fermi blazars, which sometimes shows quasi-periodic oscillation (QPO). In this work, we obtain 5 day binned light curves (with a time coverage of ∼12.9 yr) for S5 1044+71, based on Fermi-LAT data; apply five different methods—Date-compensated Discrete Fourier Transform, Jurkevich, Lomb–Scargle Periodogram, a Fortran 90 program, and the Weighted Wavelet Z-transform—to the γ-ray light curve; and find a possible QPO of 3.06 ± 0.43 yr at the significance level of ∼3.6σ. A binary black hole model, including an accretion model and a dual-jet model, is used to explain this quasi-periodic variability. We also estimate the Doppler factors and the apparent velocity for the two jet components. We speculate that this γ-ray quasi-periodic modulation suggests the presence of a binary supermassive black hole in S5 1044+71.
The Stellar Metallicities of Massive Quiescent Galaxies at 1.0 < z < 1.3 from KMOS + VANDELS
Authors: Carnall Adam C. , McLure Ross J. , Dunlop James S. , Hamadouche Massissilia , Cullen Fergus , McLeod Derek J. , Begley Ryan , Amorin Ricardo , Bolzonella Micol , Castellano Marco , Cimatti Andrea , Fontanot Fabio , Gargiulo Adriana , Garilli Bianca , Mannucci Filippo , Pentericci Laura , Talia Margherita , Zamorani Giovani , Calabro Antonello , Cresci Giovanni , Hathi Nimish P. 
Published: April 2022

Abstract
We present a rest-frame UV–optical (λ = 2500–6400 Å) stacked spectrum representative of massive quiescent galaxies at 1.0 < z < 1.3 with log(M
*/M
⊙) > 10.8. The stack is constructed using VANDELS survey data, combined with new KMOS observations. We apply two independent full-spectral-fitting approaches, measuring a total metallicity [Z/H] = −0.13 ± 0.08 with Bagpipes and [Z/H] = 0.04 ± 0.14 with Alf, a fall of ∼0.2–0.3 dex compared with the local universe. We also measure an iron abundance [Fe/H] = −0.18 ± 0.08, a fall of ∼0.15 dex compared with the local universe. We measure the alpha enhancement via the magnesium abundance, obtaining [Mg/Fe] = 0.23 ± 0.12, consistent with galaxies of similar mass in the local universe, indicating no evolution in the average alpha enhancement of log(M
*/M
⊙) ∼ 11 quiescent galaxies over the last ∼8 Gyr. This suggests the very high alpha enhancements recently reported for several bright z ∼ 1–2 quiescent galaxies are due to their extreme masses, log(M
*/M
⊙) ≳ 11.5, in accordance with the well-known downsizing trend, rather than being typical of the z ≳ 1 population. The metallicity evolution we observe with redshift (falling [Z/H], [Fe/H], constant [Mg/Fe]) is consistent with recent studies. We recover a mean stellar age of

2.5

−
0.4

+
0.6

Gyr, corresponding to a formation redshift

z

form

=

2.4

−
0.3

+
0.6

. Recent studies have obtained varying average formation redshifts for z ≳ 1 massive quiescent galaxies, and, as these studies report consistent metallicities, we identify models with different star formation histories as the most likely cause. Larger spectroscopic samples from upcoming ground-based instruments will provide precise constraints on ages and metallicities at z ≳ 1. Combining these with precise stellar mass functions for z > 2 quiescent galaxies from the James Webb Space Telescope will provide an independent test of formation redshifts derived from spectral fitting.
Continuous Habitable Zones: Using Bayesian Methods to Prioritize Characterization of Potentially Habitable Worlds
Authors: Ware Austin , Young Patrick , Truitt Amanda , Spacek Alexander 
Published: April 2022

Abstract
The number of potentially habitable planets continues to increase, but we lack the time and resources to characterize all of them. With ∼30 known potentially habitable planets and an ever-growing number of candidate and confirmed planets, a robust statistical framework for prioritizing characterization of these planets is desirable. Using the ∼2 Gyr it took life on Earth to make a detectable impact on the atmosphere as a benchmark, we use a Bayesian statistical method to determine the probability that a given radius around a star has been continuously habitable for 2 Gyr. We perform this analysis on nine potentially habitable exoplanets with planetary radii <1.8 R
⊕ and/or planetary masses <10 M
⊕ around nine low-mass host stars (∼0.5–1.1 M
⊙) with measured stellar mass and metallicity, as well as Venus, Earth, and Mars. Ages for the host stars are generated by the analysis. The technique is also used to provide age estimates for 2768 low-mass stars (0.5–1.3 M
⊙) in the TESS Continuous Viewing Zones.
Pressure–Strain Interaction as the Energy Dissipation Estimate in Collisionless Plasma
Authors: Yang 杨 Yan 艳 , Matthaeus William H. , Roy Sohom , Roytershteyn Vadim , Parashar Tulasi N. , Bandyopadhyay Riddhi , Wan 万 Minping 敏平 
Published: April 2022

Abstract
The dissipative mechanism in weakly collisional plasma is a topic that pervades decades of studies without a consensus solution. We compare several energy dissipation estimates based on energy transfer processes in plasma turbulence and provide justification for the pressure–strain interaction as a direct estimate of the energy dissipation rate. The global and scale-by-scale energy balances are examined in 2.5D and 3D kinetic simulations. We show that the global internal energy increase and the temperature enhancement of each species are directly tracked by the pressure–strain interaction. The incompressive part of the pressure–strain interaction dominates over its compressive part in all simulations considered. The scale-by-scale energy balance is quantified by scale filtered Vlasov–Maxwell equations, a kinetic plasma approach, and the lag dependent von Kármán–Howarth equation, an approach based on fluid models. We find that the energy balance is exactly satisfied across all scales, but the lack of a well-defined inertial range influences the distribution of the energy budget among different terms in the inertial range. Therefore, the widespread use of the Yaglom relation in estimating the dissipation rate is questionable in some cases, especially when the scale separation in the system is not clearly defined. In contrast, the pressure–strain interaction balances exactly the dissipation rate at kinetic scales regardless of the scale separation.
The X-Ray Coronae in NuSTAR Bright Active Galactic Nuclei
Authors: Kang Jia-Lai , Wang Jun-Xian 
Published: April 2022

Abstract
We present a systematic and uniform analysis of NuSTAR data of a sample of 60 SWIFT BAT-selected AGNs with 10–78 keV signal-to-noise ratio (S/N) > 50, 10 of which are radio loud. We measure their high-energy cutoff E
cut or coronal temperature T
e using three different spectral models to fit their NuSTAR spectra and show that a threshold in NuSTAR spectral S/N is essential for such measurements. High-energy spectral breaks are detected in the majority of the sample, and for the rest, strong constraints on E
cut or T
e are obtained. Strikingly, we find extraordinarily large E
cut lower limits (>400 keV, up to >800 keV) in 10 radio-quiet sources, whereas we find none in the radio-loud sample. Consequently and surprisingly, we find a significantly larger mean E
cut/T
e of radio-quiet sources compared with radio-loud ones. The reliability of these measurements is carefully inspected and verified with simulations. We find a strong positive correlation between E
cut and photon index Γ, which cannot be attributed to the parameter degeneracy. The strong dependence of E
cut on Γ, which could fully account for the discrepancy of the E
cut distribution between radio-loud and radio-quiet sources, indicates that the X-ray coronae in AGNs with steeper hard X-ray spectra have on average higher temperature and thus smaller opacity. However, no prominent correlation is found between E
cut and λ
edd. In the l–Θ diagram, we find a considerable fraction of sources lie beyond the boundaries of forbidden regions due to runaway pair production, posing (stronger) challenges to various (flat) coronal geometries.
Carbon Abundances in Compact Galactic Planetary Nebulae: An Ultraviolet Spectroscopic Study with the Space Telescope Imaging Spectrograph (STIS)
Authors: Stanghellini Letizia , Bushra Rafia , Shaw Richard A. , Dell’Agli Flavia , García-Hernández D. A. , Ventura Paolo 
Published: April 2022

Abstract
We surveyed a sample of compact Galactic planetary nebulae (PNe) with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope (HST) to determine their gas-phase carbon abundances. Carbon abundances in PNe constrain the nature of their asymptotic giant branch (AGB) progenitors, as well as cosmic recycling. We measured the carbon abundances, or the limits thereof, of 11 compact Galactic PNe, notably increasing the sample of Galactic PNe whose carbon abundance based on HST ultraviolet spectra is available. The dust content of most targets has been studied elsewhere from Spitzer spectroscopy; given the compact nature of the nebulae, both UV and IR spectra can be directly compared to study gas- and dust-phase carbon. We found that carbon-poor (C/O < 1) compact Galactic PNe have an oxygen-rich dust type, while their carbon-enhanced counterparts (C/O > 1) have carbon-rich dust, confirming the correlation between gas- and dust-phase carbon content that was known for Magellanic Cloud PNe. Based on models of expected final yields from AGB evolution, we interpret the majority of the carbon-poor PNe in this study as the progeny of ∼1.1–1.2 M
⊙ stars that experienced some extra mixing on the red giant branch. They went through the AGB but did not go through the carbon star phase. Most PNe in this group have a bipolar morphology, possibly due to the presence of a subsolar companion. The carbon-enhanced PNe in our sample could be the progeny of stars in the ∼1.5–2.5 M
⊙ range, depending on their original metallicity.
An Empirical Representation of a Physical Model for the ISM [C ii], CO, and [C i] Emission at Redshift 1 ≤ z ≤ 9
Authors: Yang Shengqi , Popping Gergö , Somerville Rachel S. , Pullen Anthony R. , Breysse Patrick C. , Maniyar Abhishek S. 
Published: April 2022

Abstract
Submillimeter emission lines produced by the interstellar medium (ISM) are strong tracers of star formation and are some of the main targets of line intensity mapping (LIM) surveys. In this work we present an empirical multiline emission model that simultaneously covers the mean, scatter, and correlations of [C ii], CO J = 1–0 to J = 5–4, and [C i] lines in the redshift range 1 ≤ z ≤ 9. We assume that the galaxy ISM line emission luminosity versus halo mass relations can be described by double power laws with redshift-dependent lognormal scatter. The model parameters are then derived by fitting to the state-of-the-art semianalytic simulation results that have successfully reproduced multiple submillimeter line observations at 0 ≤ z ≲ 6. We cross-check the line emission statistics predicted by the semianalytic simulation and our empirical model, finding that at z ≥ 1 our model reproduces the simulated line intensities with fractional error less than about 10%. The fractional difference is less than 25% for the power spectra. Grounded on physically motivated and self-consistent galaxy simulations, this computationally efficient model will be helpful in forecasting ISM emission-line statistics for upcoming LIM surveys.
A Reanalysis of Public Galactic Bulge Gravitational Microlensing Events from OGLE-III and -IV
Authors: Golovich Nathan , Dawson William , Bartolić Fran , Lam Casey Y. , Lu Jessica R. , Medford Michael S. , Schneider Michael D. , Chapline George , Schlafly Edward F. , Drlica-Wagner Alex , Pruett Kerianne 
Published: April 2022

Abstract
Modern surveys of gravitational microlensing events have progressed to detecting thousands per year, and surveys are capable of probing Galactic structure, stellar evolution, lens populations, black hole physics, and the nature of dark matter. One of the key avenues for doing this is the microlensing Einstein radius crossing time (t
E) distribution. However, systematics in individual light curves as well as oversimplistic modeling can lead to biased results. To address this, we developed a model to simultaneously handle the microlensing parallax due to Earth's motion, systematic instrumental effects, and unlensed stellar variability with a Gaussian process model. We used light curves for nearly 10,000 OGLE-III and -IV Milky Way bulge microlensing events and fit each with our model. We also developed a forward model approach to infer the t
E distribution by forward modeling from the data rather than using point estimates from individual events. We find that modeling the variability in the baseline removes a source of significant bias in individual events, and the previous analyses overestimated the number of t
E > 100 day events due to their oversimplistic model ignoring parallax effects. We use our fits to identify the hundreds filling a regime in the microlensing parameter space that are 50% pure of black holes. Finally, we have released the largest-ever catalog of Markov Chain Monte Carlo parameter estimates for microlensing events.
Monitoring bumblebee pollinator visits to the medicinal plant Gentiana asclepiadea L. (Gentianacese) – a comparison between the periods 1990–1994 and 2017–2020
Authors: Kozuharova Ekaterina , Simeonov Vasil 
Published: April 2022

Ever increasing data continue to indicate the decline of bumblebee populations. The key factors causing declines in their abundance and diversity are: 1) habitat destruction, 2) loss of floral resources, 3) emerging diseases, 4) increased use of pesticides (particularly neonicotinoids).
The aim of this study is to monitor bumblebee visits to Gentiana asclepiadea L, recording pollinator species, and taking measurements of seed set. This plant species is chosen for two reasons: 1) similar data is available from our previous research in the 1990’s and 2) this montane plant species is supposed to be less exposed to hazards from pesticides and habitat destruction. Three study sites were chosen in Mt. Vitosha (SW Bulgaria) where natural populations of G. asclepiadea occur in 1990. The observations of bumblebee activity in the flowers of G. asclepiadea were conducted during the flowering seasons (August and September) of 2017 – 2020 at the same study sites and compared to the data obtained in the previous period (1990–1994). The free pollination fruit set was tested by monitoring of 100 G. asclepiadea flowers each year for development of fruit capsules. The seed set was tested by counting the matured seeds and non-fertilised ovules of 10 fruit capsules each year. A slight decline in bumblebee activity was recorded in 2017 – 2020 in comparison to 1990–1994. This is reflected in the fruit set and the seed set. Our data demonstrates that even in a mountain habitat, where there are fewer direct hazards to bumblebees, that pollination effectiveness has been suppressed over time. This corresponds to a research study which provides evidence that insect biomass fell by 76% in German nature reserves between 1989 and 2016.
Comment les atteintes à la santé deviennent-elles tangibles ? Le travail de constat des agents de contrôle de l’inspection du travail
Authors: Bonanno Anaïs 
Published: April 2022

L’article entend contribuer à l’étude des conditions de judiciarisation pénale des atteintes à la santé au travail, en analysant les opérations par lesquelles les agents de l’inspection du travail produisent des constats en vue d’une communication au parquet. Deux facettes de cette matérialisation des faits sont distinguées : les infractions concernant des dommages physiques et celles qui engagent des souffrances psychiques, pour comprendre le faible nombre de procès-verbaux dressés en matière de risques psychosociaux par l’inspection du travail. Il analyse ce faisant les différences de contraintes et de ressources que la situation de travail fournit à la matérialisation, de moyens d’action procurés par le droit et d’anticipation du suivi des procédures par l’institution pénale.
L’université finlandaise comme entreprise dans les procès d’universitaires licenciés en 2016
Authors: Keryell Gaëla 
Published: April 2022

En nous appuyant sur des contentieux juridiques entre une université finlandaise et des universitaires congédiés lors d’un licenciement collectif, nous examinons comment les décisions de justice participent à la transformation des représentations du travail des enseignants-chercheurs en Finlande. Dans quelle mesure le traitement juridique de ces litiges, en s’inscrivant d’emblée dans le cadre de lois applicables aux salariés ou aux entreprises, et en recourant à une jurisprudence construite à partir de cas concernant des entreprises « classiques », contribue-t-il à instituer l’université comme une « entreprise » ordinaire et l’activité universitaire comme une activité de « production » comme une autre ?
Cas en Management des Achats
Authors: Huc Morgan , Donsimoni Caroline , Paché Gilles 
Published: April 2022

Le cas AP-HM aborde le Management des Achats en contexte d’achat public (hospitalier), face à une situation de crise majeure. Lors du printemps 2020, la pandémie de Covid-19 a effectivement produit des ruptures dans l’approvisionnement des équipements de protection individuelle (EPI) et des articles d’hygiène à usage unique, mettant en danger la vie des soignants. Le cas expose les décisions prises à trois niveaux pour surmonter les difficultés : la mise en place d’une cellule de crise ; la profonde modification de la politique d’achat ; le processus de sécurisation des achats.
Cas en Management des Achats
Authors: Beaulieu Martin , Tchokogué André , Nollet Jean 
Published: April 2022

La province de Québec (Canada) a développé un cadre législatif très élaboré en ce qui concerne la gestion des achats dans le secteur public, lequel inclue le secteur des municipalités et des villes. Justement, ce cadre a balisé l’évaluation du rendement des fournisseurs par les villes et municipalités. Le cas présente le déploiement de cette approche dans la ville de Lévis ; et ce faisant, met en évidence les enjeux qui y sont associés tant pour les gestionnaires des achats que pour les fournisseurs.