bluuebunny/crossref_metadata_2025_split huggingface dataset:
IRIS Observations of Magnetic Interactions in the Solar Atmosphere between Preexisting and Emerging Magnetic Fields. I. Overall Evolution
Authors: Guglielmino Salvo L. , Zuccarello Francesca , Young Peter R. , Murabito Mariarita , Romano Paolo 
Published: April 2018

Abstract
We report multiwavelength ultraviolet observations taken with the IRIS satellite, concerning the emergence phase in the upper chromosphere and transition region of an emerging flux region (EFR) embedded in the preexisting field of active region NOAA 12529 in the Sun. IRIS data are complemented by full-disk observations of the Solar Dynamics Observatory satellite, relevant to the photosphere and the corona. The photospheric configuration of the EFR is also analyzed by measurements taken with the spectropolarimeter on board the Hinode satellite, when the EFR was fully developed. Recurrent intense brightenings that resemble UV bursts, with counterparts in all coronal passbands, are identified at the edges of the EFR. Jet activity is also observed at chromospheric and coronal levels, near the observed brightenings. The analysis of the IRIS line profiles reveals the heating of dense plasma in the low solar atmosphere and the driving of bidirectional high-velocity flows with speed up to 100 km s−1 at the same locations. Compared with previous observations and numerical models, these signatures suggest evidence of several long-lasting, small-scale magnetic reconnection episodes between the emerging bipole and the ambient field. This process leads to the cancellation of a preexisting photospheric flux concentration and appears to occur higher in the atmosphere than usually found in UV bursts, explaining the observed coronal counterparts.
Multi-phase Turbulence Density Power Spectra in the Perseus Molecular Cloud
Authors: Pingel N. M. , Lee Min-Young , Burkhart Blakesley , Stanimirović Snežana 
Published: April 2018

Abstract
We derive two-dimensional spatial power spectra of four distinct interstellar medium tracers, H i, 12CO(J = 1–0), 13CO(J = 1–0), and dust, in the Perseus molecular cloud, covering linear scales ranging from ∼0.1 pc to ∼90 pc. Among the four tracers, we find the steepest slopes of −3.23 ± 0.05 and −3.22 ± 0.05 for the uncorrected and opacity-corrected H i column density images. This result suggests that the H i in and around Perseus traces a non-gravitating, transonic medium on average, with a negligible effect from opacity. On the other hand, we measure the shallowest slope of −2.72 ± 0.12 for the 2MASS dust extinction data and interpret this as the signature of a self-gravitating, supersonic medium. Possible variations in the dust-to-gas ratio likely do not alter our conclusion. Finally, we derive slopes of −3.08 ± 0.08 and −2.88 ± 0.07 for the 12CO(1–0) and 13CO(1–0) integrated intensity images. Based on theoretical predictions for an optically thick medium, we interpret these slopes of roughly −3 as implying that both CO lines are susceptible to the opacity effect. While simple tests for the impact of CO formation and depletion indicate that the measured slopes of 12CO(1–0) and 13CO(1–0) are not likely affected by these chemical effects, our results generally suggest that chemically more complex and/or fully optically thick media may not be a reliable observational tracer for characterizing turbulence.
The Effect of Ionic Correlations on Radiative Properties in the Solar Interior and Terrestrial Experiments
Authors: Krief Menahem , Kurzweil Yair , Feigel Alexander , Gazit Doron 
Published: April 2018

Abstract
With the aim of solving the decade-old problem of solar opacity, we report substantial photoabsorption uncertainty due to the effect of ion–ion correlations. By performing detailed opacity calculations of the solar mixture, we find that taking into account the ionic structure changes the Rosseland opacity near the convection zone by ∼10%. We also report a ∼15% difference in the Rosseland opacity for iron, which was recently measured at the Sandia Z facility, where the temperature reached that prevailing in the convection zone boundary while the density was 2.5 times lower. Finally, we propose a method to measure opacities at solar temperatures and densities that have never been reached in the past via laboratory radiation flow experiments, by using plastic foams doped with permilles of dominant photon absorbers in the Sun. The method is advantageous for an experimental study of solar opacities that may lead to a resolution of the solar abundance problem.
Survey of Water and Ammonia in Nearby Galaxies (SWAN): Resolved Ammonia Thermometry and Water and Methanol Masers in IC 342, NGC 6946, and NGC 2146
Authors: Gorski Mark , Ott Jürgen , Rand Richard , Meier David S. , Momjian Emmanuel , Schinnerer Eva 
Published: April 2018

Abstract
The Survey of Water and Ammonia in Nearby galaxies (SWAN) studies atomic and molecular species across the nuclei of four star-forming galaxies: NGC 253, IC 342, NGC 6946, and NGC 2146. As part of this survey, we present Karl G. Jansky Very Large Array molecular line observations of three galaxies: IC 342, NGC 6946, and NGC 2146. NGC 253 is covered in a previous paper. These galaxies were chosen to span an order of magnitude in star formation rates and to select a variety of galaxy types. We target the metastable transitions of ammonia NH3(1, 1) to (5, 5), the 22 GHz water (H2O) (616–523) transition, and the 36.1 GHz methanol (CH3OH) (4−1–30) transition. We use the NH3 metastable lines to perform thermometry of the dense molecular gas. We show evidence for uniform heating across the central kiloparsec of IC 342 with two temperature components for the molecular gas, similar to NGC 253, of 27 and 308 K, and that the dense molecular gas in NGC 2146 has a temperature <86 K. We identify two new water masers in IC 342, and one new water maser in each of NGC 6946 and NGC 2146. The two galaxies NGC 253 and NGC 2146, with the most vigorous star formation, host H2O kilomasers. Lastly, we detect the first 36 GHz CH3OH masers in IC 342 and NGC 6946. For the four external galaxies the total CH3OH luminosity in each galaxy suggests a correlation with galactic star formation rate, whereas the morphology of the emission is similar to that of HNCO, a weak shock tracer.
Using Strong Gravitational Lensing to Identify Fossil Group Progenitors
Authors: Johnson Lucas E. , Irwin Jimmy A. , White Raymond E. , Wong Ka-Wah , Maksym W. Peter , Dupke Renato A. , Miller Eric D. , Carrasco Eleazar R. 
Published: April 2018

Abstract
Fossil galaxy systems are classically thought to be the end result of galaxy group/cluster evolution, as galaxies experiencing dynamical friction sink to the center of the group potential and merge into a single, giant elliptical that dominates the rest of the members in both mass and luminosity. Most fossil systems discovered lie within z < 0.2, which leads to the question, what were these systems’ progenitors? Such progenitors are expected to have imminent or ongoing major merging near the brightest group galaxy that, when concluded, will meet the fossil criteria within the look forward time. Since strong gravitational lensing preferentially selects groups merging along the line of sight, or systems with a high mass concentration like fossil systems, we searched the CASSOWARY survey of strong-lensing events with the goal of determining whether lensing systems have any predisposition to being fossil systems or progenitors. We find that ∼13% of lensing groups are identified as traditional fossils while only ∼3% of nonlensing control groups are. We also find that ∼23% of lensing systems are traditional fossil progenitors compared to ∼17% for the control sample. Our findings show that strong-lensing systems are more likely to be fossil/pre-fossil systems than comparable nonlensing systems. Cumulative galaxy luminosity functions of the lensing and nonlensing groups also indicate a possible, fundamental difference between strong-lensing and nonlensing systems’ galaxy populations, with lensing systems housing a greater number of bright galaxies even in the outskirts of groups.
High-resolution Spectroscopic Abundances of Red Giant Branch Stars in NGC 6584 and NGC 7099
Authors: O’Malley Erin M. , Chaboyer Brian 
Published: April 2018

Abstract
We obtain high-resolution spectra of red giant branch stars in NGC 6584 and NGC 7099 to perform a detailed abundance analysis. We confirm cluster membership for these stars based on consistent radial velocities measured in this study and small pixel offsets between the observations of Sarajedini et al. and Piotto et al. We find mean metallicities of [Fe/H] = −1.53 ± 0.08 dex and [Fe/H] = −2.29 ± 0.07 dex for NGC 6584 and NGC 7099, respectively. We also find these clusters to be enhanced in their [α/Fe] ratios, consistent with what is expected for metal-poor globular clusters. Additionally, we find evidence of a statistically significant Na–O anti-correlation in both clusters. Finally, with the use of HST photometry, we compare the location of the enhanced and pristine populations in chromosome maps of the clusters to confirm previous photometric evidence of multiple stellar populations. Although we cannot confirm the nature of the polluter stars responsible for the abundance differences, our results can be used to constrain pollution models.
Evidence for Pulsar-like Emission Components in the Broadband ULX Sample
Authors: Walton D. J. , Fürst F. , Heida M. , Harrison F. A. , Barret D. , Stern D. , Bachetti M. , Brightman M. , Fabian A. C. , Middleton M. J. 
Published: April 2018

Abstract
We present broadband X-ray analyses of a sample of bright ultraluminous X-ray sources (ULX) with the goal of investigating the spectral similarity of this population to the known ULX pulsars, M82 X-2, NGC 7793 P13, and NGC 5907 ULX. We perform a phase-resolved analysis of the broadband XMM-Newton+NuSTAR data set of NGC 5907 ULX, finding that the pulsed emission from the accretion column in this source exhibits a similar spectral shape to that seen in both M82 X-2 and NGC 7793 P13, and that this is responsible for the excess emission observed at the highest energies when the spectra are fit with accretion disk models. We then demonstrate that similar “hard” excesses are seen in all ULXs in the broadband sample. Finally, for ULXs where the nature of the accretor is currently unknown, we test whether the hard excesses are all consistent with being produced by an accretion column similar to those present in M82 X-2, NGC 7793 P13, and NGC 5907 ULX. Based on the average shape of the pulsed emission, we find that in all cases a similar accretion column can successfully reproduce the observed data, consistent with the hypothesis that this ULX sample may be dominated by neutron star accretors. Compared to the known pulsar ULXs, our spectral fits for the remaining ULXs suggest that the non-pulsed emission from the accretion flow beyond the magnetosphere makes a stronger relative contribution than the component associated with the accretion column. If these sources do also contain neutron star accretors, this may help to explain the lack of detected pulsations.
The 3CR Chandra Snapshot Survey: Extragalactic Radio Sources with Redshifts between 1 and 1.5
Authors: Stuardi C. , Missaglia V. , Massaro F. , Ricci F. , Liuzzo E. , Paggi A. , Kraft R. P. , Tremblay G. R. , Baum S. A. , O’Dea C. P. , Wilkes B. J. , Kuraszkiewicz J. , Forman W. R. , Harris D. E. 
Published: April 2018

Abstract
The aim of this paper is to present an analysis of newly acquired X-ray observations of 16 extragalactic radio sources listed in the Third Cambridge Revised (3CR) catalog and not previously observed by Chandra. Observations were performed during Chandra Cycle 17, extending X-ray coverage for the 3CR extragalactic catalog up to z = 1.5. Among the 16 targets, two lie at z < 0.5 (3CR 27 at z = 0.184 and 3CR 69 at z = 0.458); all of the remaining 14 have redshifts between 1.0 and 1.5. In the current sample, there are three compact steep spectrum (CSS) sources, three quasars, and an FR I radio galaxy, while the other nine are FR II radio galaxies. All radio sources have an X-ray counterpart. We measured nuclear X-ray fluxes as well as X-ray emission associated with radio jet knots, hotspots, or lobes in three energy bands: soft (0.5–1 keV), medium (1–2 keV), and hard (2–7 keV). We also performed standard X-ray spectral analysis for the four brightest nuclei. We discovered X-ray emission associated with the radio lobe of 3CR 124, a hotspot of the quasar 3CR 220.2, another hotspot of the radio galaxy 3CR 238, and the jet knot of 3CR 297. We also detected extended X-ray emission around the nuclear region of 3CR 124 and 3CR 297 on scales of several tens of kiloparsecs. Finally, we present an update on the X-ray observations performed with Chandra and XMM-Newton on the entire 3CR extragalactic catalog.
Inflow Motions Associated with High-mass Protostellar Objects
Authors: Yoo Hyunju , Kim Kee-Tae , Cho Jungyeon , Choi Minho , Wu Jingwen , Evans Neal J. , Ziurys L. M. 
Published: April 2018

Abstract
We performed a molecular line survey of 82 high-mass protostellar objects in a search for inflow signatures associated with high-mass star formation. Using the H13CO+ (1−0) line as an optically thin tracer, we detected a statistically significant excess of blue asymmetric line profiles in the HCO+ (1−0) transition, but nonsignificant excesses in the HCO+ (3−2) and H2CO (212–111) transitions. The negative blue excess for the HCN (3−2) transition suggests that the line profiles are affected by dynamics other than inflow motion. The HCO+ (1−0) transition thus seems to be the suitable tracer of inflow motions in high-mass star-forming regions, as previously suggested. We found 27 inflow candidates that have at least 1 blue asymmetric profile and no red asymmetric profile, and derived the inflow velocities to be 0.23−2.00 km s−1 for 20 of them using a simple two-layer radiative transfer model. Our sample is divided into two groups in different evolutionary stages. The blue excess of the group in relatively earlier evolutionary stages was estimated to be slightly higher than that of the other in the HCO+ (1−0) transition.
Dataset of long-term monitoring of ground-dwelling ants (Hymenoptera: Formicidae) in the influence areas of a hydroelectric power plant on the Madeira River in the Amazon Basin
Authors: Fernandes Itanna , de Souza Jorge 
Published: April 2018

Biodiversity loss is accelerating rapidly in response to increasing human influence on the Earth’s natural ecosystems. One way to overcome this problem is by focusing on places of human interest and monitoring the changes and impacts on the biodiversity. This study was conducted at six sites within the influence area of the Santo Antônio Hydroelectric Power Plant in the margins of the Madeira River in Rondônia State. The sites cover a latitudinal gradient of approximately 100 km in the Brazilian Amazon Basin. The sampling design included six sampling modules with six plots (transects) each, totaling 30 sampling plots. The transects were distributed with 0 km, 0.5 km, 1 km, 2 km, 3 km and 4 km, measured perpendicularly from the river margin towards the interior of the forest. For sampling the ground-dwelling ants, the study used the ALL (ants of the leaf litter) protocol, which is standardized globally in the inventories of ant fauna. For the purpose of impact indicators, the first two campaigns (September 2011 to November 2011) were carried out in the pre-filling period, while campaigns 3 to 10 (February 2012 to November 2014) were carried out during and after the filling of the hydroelectric reservoir. A total of 253 events with a total of 9,165 occurrences were accounted during the monitoring. The ants were distributed in 10 subfamilies, 68 genera and 324 species/morphospecies. The impact on ant biodiversity during the periods before and after filling was measured by ecological indicators and by the presence and absence of some species/morphospecies. This is the first study, as far as we know, including taxonomic and ecological treatment to monitor the impact of a hydroelectric power plant on ant fauna.
Until recently, most studies conducted on hydroelectric plants, located in the Amazon Basin, were carried out after the implementation of dams in order to assess their impacts on the environment and biodiversity (Benchimol and Peres 2015, Latrubesse et al. 2017, Sá-Oliveira et al. 2015). Recent studies on dam impacts have begun to be conducted prior to dam implementation (e.g. Bobrowiec and Tavares 2017, Fraga et al. 2014, Moser et al. 2014), thus providing a better overview of the impact and a better assessment of its magnitude.
Un média naît toujours deux fois...
Authors: Gaudreault André , Marion Philippe 
Published: April 2018

L'étude de la « naissance » du cinéma, qui a été un processus relativement lent, révèle que l'affirmation de l'identité singulière du média cinématographique a été loin de s'imposer d'emblée. L'histoire du cinéma des premiers temps pourrait se lire comme un passage articulé selon trois termes en gradation : l'apparition d'une technologie, les « machines à vues », l'émergence d'un dispositif, celui des « vues animées », puis l'avènement d'une institution, celle du « cinéma ». Tout en considérant ce dernier comme prototype, ces trois termes peuvent constituer la base d'une généralisation théorique, appelée ici « modèle de la double naissance des médias ». Ainsi basé sur le cinéma mais ayant l'ambition de faire progresser la généalogie des médias toute entière, ce projet de modèle dynamique sera confronté à la genèse d'autres médias iconiques comme la photo, la BD ou, plus succinctement, à quelques formes médiatiques plus récentes.
Relation intermédiale entre le théâtre et le cinéma
Authors: Sokalski Joseph A. 
Published: April 2018

Cet article se veut une réfléxion sur la relation entre le cinéma et le théâtre à travers un examen de l'expression « images animées ». On y défend l'idée que les pratiques théâtrales du XIX e siècle impliquaient une conception des images animées passablement différente de celle du cinéma. Cet essai s'arrête particulièrement sur un projet théâtral où des paysages en trois dimensions étaient déplacés physiquement à travers un cadre scénique comprenant des images en deux dimensions. Le spectateur étant témoin d'une transformation continue, on peut dire que des « images vivantes animées » étaient véritablement créées sur la scène. L'auteur conclut en affirmant que l'expression « images animées » doit être réexaminée, les événements historiques montrant qu'elle devrait être plus inclusive. Cela nous empêcherait de considérer cette expression comme synonyme de « cinéma ». Un tel repositionnement critique pourrait ainsi nous permettre d'analyser le développement actuel des images digitales sans faire des associations inadéquates avec la technologie du cinéma.
Du nouveau et de l'ancien
Authors: Sicard Monique 
Published: April 2018

Photographie, cinématographie, télévision, images numériques et circulations en réseaux... : depuis les débuts du XIX e siècle, l'arrivée de chaque nouvelle technique de l'image fut saluée par des références héritées des techniques antérieures. Pourtant, ces images nouvelles n'ont pas anéanti celles qui les précédaient. La circulation de modèles à contre-courant (du nouveau vers l'ancien) montre à l'inverse qu'elles leur ont conféré un nouvel élan. Ces cheminements à double sens entre l'ancien et le nouveau invitent à faire resurgir les socles matériels dans lesquels s'enracine la pensée de l'image. Elles conduisent à une critique d'une histoire qui se bâtirait chronologiquement. Si l'ancien est perçu par le socle du présent, s'il est « ce qui conduit au présent », il n'est pas cause mais conséquence de ce dernier. Le présent est alors cause du passé
La fin de l' aura ?
Authors: Sorlin Pierre 
Published: April 2018

La photographie a-t-elle marqué la fin de l'aura dont était auparavant entourée l'œuvre d'art ? L'article tente de suggérer une réponse en comparant la réaction face à la peinture de deux romanciers également épris d'art italien, Stendhal qui n'a rien connu de la photographie et John Ruskin qui était photographe. Leurs approches sont extrêmement différentes, mais l'écart tient à un profond bouleversement dans la manière d'envisager la production artistique, la photographie, fort utile à Ruskin, n'a été pour lui qu'un outil dans une très large révision des critères d'évaluation. L'aura s'est effacée quand on est passé de la collection privée chère à Stendhal au musée ouvert au public.
Sémio-pragmatique et intermédialité
Authors: Odin Roger 
Published: April 2018

Pour la sémio-pragmatique, l'intermédialité est d'abord une approche : il s'agit de procéder à une comparaison systématique entre les médias pour mieux comprendre comment ils fonctionnent. Cette réflexion permet de mettre en évidence certains phénomènes intermédiatiques : l'insistance est mise ici sur quelques aspects intermédiatiques du cinéma des premiers temps. On montre également comment cette étude du cinéma des premiers temps peut aider à comprendre ce qui se passe aujourd'hui.
L'écran : une impression pérégrine
Authors: Pons Christian-Marie , Bleton Paul 
Published: April 2018

À la question de l'impact des TIC (technologies fondées sur la numérisation de la communication) sur la pensée, des philosophes comme Pierre Lévy ou Ann Van Sevenant ont déjà proposé quelques réponses qui soulevaient une autre question : comment des technologies aussi révolutionnaires ont-elles pu s'insérer aussi aisément dans nos pratiques intellectuelles depuis la micro-informatique ? Leur appropriation à large échelle constitue en effet une condition de possibilité déterminante de l'évolution de l'organisation de savoirs. Les auteurs suggèrent que si les technologies sont nouvelles, les formes codantes qu'elles supportent le sont peut-être moins. Aussi, plutôt que de repérer une technologie derrière cet écran de moniteur qui en est venu à emblématiser l'accès universel à la communication numérisée, ils proposent de le saisir comme révélateur et mémoire de ce qu'il révèle, comme rémanences de pratiques anciennes dans la cybermodemité. Ils examinent donc successivement les strates de la page, de la fenêtre, du miroir, du portulan et des cartes.
Les Faux-monnayeurs de la Cueille
Authors: Augustin Jean-Marie 
Published: April 2018

En 1876, un chaudronnier et un étameur ambulant fabriquèrent de fausses pièces d'argent dans une maison du faubourg de la Cueille à Poitiers. Us furent condamnés par la cour d'assises de la Vienne, l'un à cinq ans de réclusion criminelle, l'autre aux travaux forcés à perpétuité. C'étaient de pauvres artisans, des besogneux de la fausse monnaie. Face à la police et aux magistrats, ils avouèrent tout de suite et s'inclinèrent devant la fatalité des événements.
Femmes de Dieu et Justice de l'an II
Authors: Murphy Gwénaël 
Published: April 2018

Les trajectoires des religieuses pendant la Terreur sont mal connues. L'Histoire a retenu essentiellement les exécutions des Carmélites de Compiègne, canonisées en littérature par Bernanos ou celles des religieuses d'Orange. Si une minorité (environ 200 sur 40 000) d'anciennes religieuses subirent un sort identique, une grande partie eurent cependant des rapports avec la justice de l'an II. Emprisonnées comme filles ou sœurs d'émigré, protégeant des prêtres réfractaires, portant l'habit de religieuse ou vivant en couvent clandestin, parfois ayant rejoint les armées rebelles de l'Ouest, c'est plus de 10 % d'entre elles qui connaissent une expérience carcérale. Celle-ci se décline autour de trois temps : l'arrestation, la vie en prison et l'interrogatoire qui ouvre sur des tactiques discursives pour tenter d'obtenir des aveux ou de les éviter, le tout aboutissant sur un verdict. L'ampleur du choc revolutionnaire est en ce lieu la plus perceptible. Reste a s'interroger sur la nature de la « persecution » des religieuses : ne se trouve-t-on pas face a un processus de marginalisation sociale ?