bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Local Cluster Survey. I. Evidence of Outside-in Quenching in Dense Environments
Authors: Finn Rose A. , Desai Vandana , Rudnick Gregory , Balogh Michael , Haynes Martha P. , Jablonka Pascale , Koopmann Rebecca A. , Moustakas John , Peng Chien Y. , Poggianti Bianca , Rines Kenneth , Zaritsky Dennis 
Published: August 2018

Abstract
The goal of the Local Cluster Survey is to look for evidence of environmentally driven quenching among star-forming galaxies in nearby galaxy groups and clusters. Quenching is linked with environment and stellar mass, and much of the current observational evidence comes from the integrated properties of galaxies. However, the relative size of the stellar and star-forming disk is sensitive to environmental processing and can help identify the mechanisms that lead to a large fraction of quenched galaxies in dense environments. Toward this end, we measure the size of the star-forming disks for 224 galaxies in nine groups and clusters (0.02 < z < 0.04; SFR > 0.1 M
⊙ yr−1) using 24 μm imaging from the Spitzer Space Telescope. We normalize the 24 μm effective radius (R
24) by the size of the stellar disk (R

d
). We find that star-forming galaxies with higher bulge-to-total ratios (B/T) and galaxies in more dense environments have more centrally concentrated star formation. Comparison with H i mass fractions and NUV − r colors indicates that a galaxy’s transition from gas-rich and blue to depleted and red is accompanied by an increase in the central concentration of star formation. We build a simple model to constrain the timescale over which the star-forming disks shrink in the cluster environment. Our results are consistent with a long-timescale (>2 Gyr) mechanism that produces outside-in quenching, such as the removal of the extended gas halo or weak stripping of the cold disk gas.
Constraints on Cosmic-ray Acceleration Efficiency in Balmer Shocks of Two Young Type Ia Supernova Remnants in the Large Magellanic Cloud
Authors: Hovey Luke , Hughes John P. , McCully Curtis , Pandya Viraj , Eriksen Kristoffer 
Published: August 2018

Abstract
We present results from an optical study of two young Balmer-dominated remnants of SNIa in the Large Magellanic Cloud, 0509−67.5 and 0519−69.0, in an attempt to search for signatures of efficient cosmic-ray (CR) acceleration. We combine proper motion measurements with corresponding optical spectroscopic measurements of the Hα line at multiple rim positions from VLT/FORS2 and SALT/RSS and compare our results to published Balmer shock models. Analyses of the optical spectra result in broad Hα widths in the range of 1800–4000 km s−1 for 12 separate Balmer-dominated filaments that show no evidence for forbidden line emission; the corresponding shock speeds from proper motion measurements from HST span a range of 1700–8500 km s−1. Our measured values of shock speeds and broad Hα widths in 0509−67.5 and 0519−69.0 are fit well with a Balmer shock model that does not include effects of efficient CR acceleration. We determine an upper limit of 7%/χ (95% confidence) on the CR acceleration efficiency for our ensemble of data points, where χ is the ionization fraction of the pre-shock gas. The upper limits on the individual remnants are 6%/χ (0509−67.5) and 11%/χ (0519−69.0). These upper limits are below the integrated CR acceleration efficiency in the Tycho supernova remnant, where the shocks predominantly show little Hα emission, indicating that Balmer-dominated shocks are not efficient CR accelerators.
Gaia–ESO Survey: INTRIGOSS—A New Library of High-resolution Synthetic Spectra
Authors: Franchini Mariagrazia , Morossi Carlo , Di Marcantonio Paolo , Chavez Miguel , Gilmore Gerry , Randich Sofia , Flaccomio Ettore , Koposov Sergey E. , Korn Andreas J. , Bayo Amelia , Carraro Giovanni , Casey Andy , Franciosini Elena , Hourihane Anna , Jofré Paula , Lardo Carmela , Lewis James , Magrini Laura , Morbidelli Lorenzo , Sacco G. G. , Worley Clare , Zwitter Tomaz 
Published: August 2018

Abstract
We present a high-resolution synthetic spectral library, INTRIGOSS, designed for studying FGK stars. The library is based on atmosphere models computed with specified individual element abundances via ATLAS12 code. Normalized SPectra (NSPs) and surface Flux SPectra (FSP) in the wavelength range 4830–5400 Å were computed with the SPECTRUM code. INTRIGOSS uses the solar composition of Grevesse et al. and four [α/Fe] abundance ratios, and consists of 15,232 spectra. The synthetic spectra are computed with astrophysical gf-values derived by comparing synthetic predictions with a solar spectrum of very high signal-to-noise ratio and the UVES-U580 spectra of five cool giants. The validity of the NSPs is assessed by using the UVES-U580 spectra of 2212 stars observed in the framework of the Gaia–ESO (European Southern Observatory) survey and characterized by homogeneous and accurate atmospheric parameter values and by detailed chemical compositions. The greater accuracy of NSPs with respect to spectra from the synthetic spectral libraries AMBRE, GES_Grid, PHOENIX, C14, and B17 is demonstrated by evaluating the consistency of the predictions of the different libraries for stars in the UVES-U580 sample. The validity of the FSPs is checked by comparing their prediction with both the observed spectral energy distribution (SED) and spectral indices. The comparison of FSPs with SEDs derived from the libraries ELODIE, INDO–U.S., and MILES indicates that the former reproduce the observed flux distributions within a few per cent and without any systematic trend. The good agreement between observational and synthetic Lick/SDSS (Sloan Digital Sky Survey) indices shows that the predicted blanketing of FSPs well reproduces the observed one, thus confirming the reliability of INTRIGOSS FSPs.
Blue Straggler Stars beyond the Milky Way. II. A Binary Origin for Blue Straggler Stars in Magellanic Cloud Clusters
Authors: Sun Weijia , Li Chengyuan , Grijs Richard de , Deng Licai 
Published: August 2018

Abstract
We have analyzed populations of blue straggler stars (BSSs) in 24 Magellanic Cloud (MC) star clusters using multi-passband Hubble Space Telescope images. We compiled a homogeneous BSS database, containing both traditional and evolved BSSs. We uncovered a sublinear correlation between the number of BSSs in the cluster cores and the clusters’ core masses, characterized by a power-law index of 0.51 ± 0.07. For low stellar collision rates, the mass-normalized number of BSSs depends only weakly (or perhaps not at all) on the collision rate, implying that the binary-driven BSS formation channel dominates. Comparison with simulations suggests that stellar collisions contribute less than 20% to the total number of BSSs formed. Further tests, including the analysis of the BSS-specific frequencies and their population numbers at larger cluster radii, suggest that binary interactions may be their main formation channel, hinting at an anti-correlation between a cluster’s binary fraction and its core mass.
Average Opacity Calculation for Core-collapse Supernovae
Authors: Nagy Andrea P. 
Published: August 2018

Abstract
Supernovae (SNe) are among the most intensely studied objects of modern astrophysics, but due to their complex physical nature, theoretical models are essential to better understand these exploding stars, as well as the properties of the variation of the emitted radiation. One possibility for modeling SNe light curves (LCs) is the construction of a simplified semianalytic model, which can be used for getting order-of magnitude estimates of the SN properties. One of the strongest simplifications in most of these LC models is the assumption of the constant Thomson-scattering opacity that can be determined as the average opacity of the ejecta. Here we present a systematic analysis for estimating the average opacity in different types of core-collapse supernovae that can be used as the constant opacity of the ejecta in simplified semianalytic models. To use these average opacities self-consistently during LC fit, we estimate their values from hydrodynamic simulations. In this analysis, we first generate MESA stellar models with different physical parameters (initial mass, metallicity, and rotation), which determine the mass-loss history of the model star. Then we synthesize SN LCs from these models with the SNEC hydrodynamic code and calculate the Rosseland mean opacity in every mass element. Finally, we compute the average opacities by integrating these Rosseland mean opacities. As a result, we find that the average opacities from our calculations show adequate agreement with the opacities generally used in previous studies.
z ∼ 2.5–3 Ionizers in the GOODS-N Field
Authors: Jones L. H. , Barger A. J. , Cowie L. L. , Oesch P. , Hu E. M. , Songaila A. , Naidu R. P. 
Published: August 2018

Abstract
We use deep F275W imaging from the Hubble Deep UV Legacy Survey (HDUV) and G280 grism spectroscopy from the Hubble Space Telescope/WFC3, along with new and archival optical spectra from Keck/DEIMOS, to search for candidate ionizing sources in the GOODS-N field at z ∼ 2.5–3. Spectroscopic identification of our UV-selected sources are 99% complete to F275W = 25.5 in the region of the UV imaging, and we identify six potential ionizing galaxies or active galactic nuclei (AGNs) at z ∼ 3. By far the brightest of these is a z = 2.583 AGN that totally dominates the ionizing flux in the region, with a specific ionizing volume emissivity at 912 Å of

erg s−1 Hz−1 Mpc−3. Based on our spectroscopic data, we find that four candidates are contaminated by foreground galaxies at z ∼ 0.5–0.7. At

erg s−1 Hz−1 Mpc−3, the remaining candidate galaxy’s contribution to the ionizing background lies well below the flux required to ionize the intergalactic medium at z ∼ 2.5–3, consistent with previous observations that show that AGNs provide the bulk of the ionizing background at these redshifts.
A Photoionization Reflectron Time-of-flight Mass Spectrometric Study on the Formation of Acetic Acid (CH3COOH) in Interstellar Analog Ices
Authors: Bergantini Alexandre , Zhu Cheng , Kaiser Ralf I. 
Published: August 2018

Abstract
This work investigates the synthesis of complex organic molecules with special focus on acetic acid (CH3COOH) via experiments involving the processing of astrophysical model ices of carbon dioxide–methane (CO2–CH4) by low doses of ionizing radiation, exposing the initial bond-breaking processes and successive reactions initiated by energetic electrons generated in the track of galactic cosmic-ray particles penetrating ice-coated interstellar grains, deep inside molecular clouds in their early stages of evolution. The key results were obtained through single photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS) and exploiting isotopically labeled samples (C18O2–CH4; CO2–CD4). Not only acetic acid (CH3COOH), along with fragments of acetic acid dimers (CH3COOH)2, but also the hitherto elusive interstellar methyl hydroperoxide (CH3OOH) and the hydrocarbons ethane (C2H6) and butane (C4H10), along with species belonging to C2H4O, C2H6O, and C3H6O2 isomers, are swiftly formed via suprathermal reactions at doses of only 0.88 ± 0.12 eV per molecule of carbon dioxide and 0.32 ± 0.04 eV per molecule of methane, which is equivalent to doses deposited in just (2.0 ± 0.5) × 106 yr in a typical molecular cloud. The results suggest further that the search for acetic acid dimers (CH3COOH)2 toward star-forming regions has a significant potential to be successful. Finally, methyl hydroperoxide (CH3OOH) and dimethyl peroxide (CH3OOCH3), as identified previously in our laboratory, are predicted to be present in the interstellar medium, thus providing a homologous series of peroxides—HOOH, CH3OOH, and CH3OOCH3—to shed light on the interstellar oxygen chemistry.
A VLBI Distance and Transverse Velocity for PSR B1913+16
Authors: Deller A. T. , Weisberg J. M. , Nice D. J. , Chatterjee S. 
Published: August 2018

Abstract
Using the Very Long Baseline Array, we have made astrometric observations of the binary pulsar B1913+16 spanning an 18-month period in 2014–2015. From these observations we make the first determination of the annual geometric parallax of B1913+16, measuring

mas (68% confidence interval). The inferred parallax probability distribution differs significantly from a Gaussian. Using our parallax measurement and prior information on the spatial and luminosity distributions of the millisecond pulsar population, we infer a distance of

kpc, which is significantly closer than the 9.8 ± 3.1 kpc suggested by the pulsar’s dispersion measure (DM) and analyses of the ionized interstellar medium. While the relatively low significance of the parallax detection (∼3σ) currently precludes an improved test of general relativity using the orbital decay of PSR B1913+16, ongoing observations with improved control of systematic astrometric errors could reach the 10% distance uncertainty required for this goal. The proper motion measured by our Very Long Baseline Interferometry astrometry differs substantially from that obtained by pulsar timing, a discrepancy that has also been found between the proper motion measurements made by interferometers and pulsar timing for some other pulsars, which we speculate is the result of timing noise or DM variations in the timing data set. Our parallax and proper motion measurements yield a transverse velocity of

km s−1 in the solar reference frame. Analysis incorporating galactic rotation and solar motion finds that the space velocity of the pulsar relative to its standard of rest has a component

km s−1 perpendicular to the galactic plane and components on the order of 100 km s−1 parallel to the galactic plane.
Large-amplitude Blazar Polarization Angle Swing as a Signature of Magnetic Reconnection
Authors: Zhang Haocheng , Li Xiaocan , Guo Fan , Giannios Dimitrios 
Published: August 2018

Abstract
Relativistic magnetic reconnection events may exist in magnetized plasmas in astrophysical systems. During this process, oppositely directed magnetic field lines reconnect and release magnetic energy, efficiently accelerating nonthermal particles. However, so far there is little clear observational signatures of relativistic magnetic reconnection events in astrophysical systems. Blazars are relativistic magnetized plasma outflows from supermassive black holes. Their multi-wavelength flares may be powered by relativistic magnetic reconnection. The highly variable radiation and polarization signatures are well covered by multi-wavelength observation campaigns, making them ideal targets to examine the magnetic reconnection model. Recent observations have found that several blazar flares are accompanied by optical polarization angle swings that may have an amplitude as large as >180°, challenging existing theoretical models. In this Letter, we present integrated particle-in-cell and polarized radiation transfer simulations of magnetic reconnection events. We find that plasmoid coalescences in the reconnection layer can give rise to highly variable light curves, low and fluctuating polarization degree, and rotating polarization angle. In particular, large-amplitude polarization angle swings, similar to those observed during blazar flares, can be a unique signature of relativistic magnetic reconnection events.
Practice Variations in the Diagnosis, Monitoring, and Treatment of Systemic Lupus Erythematosus in Canada
Authors: Keeling Stephanie O. , Bissonauth Asvina , Bernatsky Sasha , Vandermeer Ben , Fortin Paul R. , Gladman Dafna D. , Peschken Christine , Urowitz Murray B. 
Published: August 2018

Objective.To evaluate the diagnosis, monitoring, and treatment of systemic lupus erythematosus (SLE) in Canada.Methods.A 63-question electronic survey was developed with the Canadian Rheumatology Association and others. Descriptive analyses of responses were performed.Results.Survey respondents (n = 175) reported varying practices in the diagnosis, monitoring, and treatment of SLE. Performance of laboratory investigations for diagnosis and monitoring varied, with 78% of responders performing them at least every 6 months. Validated measures of SLE disease activity and damage were not commonly used. Most common first-line agents besides steroids for induction therapy for class III or IV lupus nephritis included intravenous cyclophosphamide and mycophenolate mofetil. Antimalarial use was common, with 96% of respondents using these in active skin disease. Over 60% of respondents indicated that 80–100% of their patients were taking antimalarials, while another 25% indicated they used these drugs in up to 80% of their patients. There were 71% of responders who reported completing frequent (6–12 mos) ophthalmology screening in patients taking antimalarials. Biologics were infrequently used. Responders were more likely to stop azathioprine and chloroquine than hydroxychloroquine in pregnant patients with SLE. Other aspects of routine care including vaccination and cardiovascular risk management varied considerably. The majority (80%) agreed that a dedicated multidisciplinary care team would improve SLE care.Conclusion.Considerable practice variation in SLE management was noted. This may help inform future recommendations for the diagnosis, monitoring, and treatment of SLE in Canada.
Produire, consommer, vivre : les pratiques économiques du quotidien dans la Syrie en guerre (2011-2018)
Authors: Vignal Leïla 
Published: August 2018

À partir de l’exemple de la Syrie des années 2010, cet article vise à saisir les modalités de transformation de l’économie dans la guerre. À distance des études consacrées aux économies de guerre, il explore ce que devient, en temps de guerre, le quotidien économique – produire, consommer, vivre –, y compris dans le chaos des destructions, de l’effondrement du cadre collectif et des logiques partisanes, militaires ou miliciennes. Pour comprendre la reproduction du quotidien économique dans la guerre, nous identifions les innovations mais aussi les continuités de pratiques économiques (prédation et auto-organisation) qui étaient en cours dans l’État autoritaire de l’avant-guerre. Nous procédons en analysant tout d’abord la contraction des échelles de l’économie syrienne à partir de l’exemple de l’activité industrielle. Ensuite, nous montrons le déploiement d’une « économie du passage », c'est-à-dire d’un système de production de valeurs mis en place par de multiples acteurs et qui exploite la fragmentation de l’espace et des mobilités. Enfin, nous explorons le quotidien économique de la population, qui s’articule depuis l’échelle locale jusqu’aux échelles internationales.
Les caveaux funéraires mégalithiques de la vallée de l’Euphrate au Bronze Ancien
Authors: Kepinski Christine 
Published: August 2018

Le caveau funéraire de Tilbeshar, exemple unique en Turquie, se rattache à un petit corpus de tombes mégalithiques, familiales et à utilisation multiple, de la vallée de l’Euphrate, région riche de pratiques funéraires variées. Elles renferment toujours des offrandes abondantes, exotiques et précieuses. Le nombre considérable de pots en céramique induit des banquets et des rituels élaborés et réguliers ; ceux-ci sont mentionnés dans les sources écrites. Elles sont utilisées durant quelques siècles contemporains de processus de mutations sociopolitiques importantes, de l’émergence de grandes villes et vraisemblablement de structures de domination fondées sur des liens de parenté. Elles soulignent et maintiennent le statut de certaines familles.
Quelques réflexions sur les tombes intra-muros en Anatolie centrale au IIe millénaire AC
Authors: Patrier Julie 
Published: August 2018

Les pratiques funéraires en Anatolie centrale au IIe millénaire aC n’ont pratiquement jamais fait l’objet d’études jusqu’ici. J’ai donc entrepris de traiter cette question, dans le cadre de l’ANR “ViGMA. Vivre, grandir, mourir dans l’Antiquité : Rites de passage individuels au Proche-Orient ancien”, dirigée par Alice Mouton (CNRS, Strasbourg), en m’attachant plus particulièrement aux offrandes alimentaires faites aux morts.Dans cette contribution, je m’intéresse plus spécifiquement aux tombes intra-muros découvertes en Anatolie centrale au IIe millénaire aC. Après avoir présenté leurs typologies, je tente de les replacer dans le contexte historique et géographique envisagé.Fort rares sont les études portant sur les tombes intra-muros d’Anatolie centrale au IIe millénaire aC1. Il m’a donc semblé intéressant d’en proposer une vue d’ensemble dans le cadre de ces deuxièmes rencontres de l’IFEA consacrées au Mort dans la ville. Le but n’est pas de présenter une étude exhaustive, les problématiques touchant aux pratiques funéraires liées à ces tombes intra-muros ne pouvant être abordées dans leur ensemble ici, mais plutôt de proposer un premier état des connaissances en brossant, en premier lieu, un panorama général (état de la question, présentation des sources) avant de s’intéresser plus particulièrement à la situation spécifique de la période des comptoirs assyriens de Cappadoce (environ 1945-1680 aC). Certains aspects ne seront abordés que sous forme de questions auxquelles il ne sera pas toujours possible de répondre, faute le plus souvent de documentation. Par ailleurs, il me faut préciser que cet article rend compte de recherches en cours. Les conclusions qui seront livrées ici se veulent donc préliminaires.
Temporalités du street art et image des territoires en mutation
Authors: Kullmann Clotilde 
Published: August 2018

Cet article propose d’étudier les modalités et certains effets de la production et de la valorisation du street art, en tant que pratique légale et encadrée par les autorités publiques, pour valoriser l’image des territoires en mutation, à partir du cas de la Zone d’Aménagement Concerté Paris Rive Gauche dans le 13e arrondissement de Paris. Une première partie porte sur les signaux de la reconnaissance du street art en tant qu’agent de formation d’une image urbaine positive, par les acteurs de l’aménagement et de l’art, puis montre comment la pratique s’alimente des caractéristiques et de l’expérience de la mutation urbaine pour générer cette image. Une seconde partie s’attache à plusieurs effets du succès du street art dans le temps plus ou moins long. D’une part, elle met en avant une pérennisation des formes de la pratique artistique et interroge ses impacts sur les modalités des productions. D’autre part, elle démontre que la promotion du street art attire en retour le graffiti, susceptible d’enrichir l’image urbaine selon les critères d’acceptation des autorités publiques.
Déjouer la Ville Créative ?
Authors: Sallenave Léa 
Published: August 2018

En 2014, le parti écologique d’Éric Piolle remporte les municipales grenobloises. Il accepte de soutenir un nouveau festival, le Grenoble Street art Fest’. Ainsi, depuis 2015, les murs se couvrent d’images fictionnelles inédites et renouvellent l’étiquetage de la cité : elle est à la fois « branchée » et « populaire », attractive et accessible à tous. Comme toute initiative s’inscrivant dans le domaine public, celle-ci est lue tantôt de manière positive (ce festival serait un outil de valorisation territoriale, de cohésion sociale luttant contre les fragmentations spatiales), tantôt de façon critique (il déconsidérerait certains graffeurs, relèverait d’une faible qualité artistique). Quoi qu’il en soit, le festival devient prétexte pour questionner le rôle des images de rue in et off. Elles permettent d’analyser une façon dont peuvent se construire les territoires.