bluuebunny/crossref_metadata_2025_split huggingface dataset:
SMASHing the LMC: Mapping a Ring-like Stellar Overdensity in the LMC Disk
Authors: Choi Yumi , Nidever David L. , Olsen Knut , Besla Gurtina , Blum Robert D. , Zaritsky Dennis , Cioni Maria-Rosa L. , van der Marel Roeland P. , Bell Eric F. , Johnson L. Clifton , Vivas A. Katherina , Walker Alistair R. , de Boer Thomas J. L. , Noël Noelia E. D. , Monachesi Antonela , Gallart Carme , Monelli Matteo , Stringfellow Guy S. , Massana Pol , Martinez-Delgado David , Muñoz Ricardo R. 
Published: December 2018

Abstract
We explore the stellar structure of the Large Magellanic Cloud (LMC) disk using data from the Survey of the MAgellanic Stellar History and the Dark Energy Survey. We detect a ring-like stellar overdensity in the red clump star count map at a radius of ∼6° (∼5.2 kpc at the LMC distance) that is continuous over ∼270° in position angle and is only limited by the current data coverage. The overdensity shows an amplitude up to 2.5 times higher than that of the underlying smooth disk. This structure might be related to the multiple arms found by de Vaucouleurs. We find that the overdensity shows spatial correlation with intermediate-age star clusters, but not with young (<1 Gyr) main-sequence stars, indicating the stellar populations associated with the overdensity are intermediate in age or older. Our findings on the LMC overdensity can be explained by either of two distinct formation mechanisms of a ring-like overdensity: (1) the overdensity formed out of an asymmetric one-armed spiral wrapping around the LMC main body, which is induced by repeated encounters with the Small Magellanic Cloud (SMC) over the last Gyr, or (2) the overdensity formed very recently as a tidal response to a direct collision with the SMC. Although the measured properties of the overdensity alone cannot distinguish between the two candidate scenarios, the consistency with both scenarios suggests that the ring-like overdensity is likely a product of tidal interaction with the SMC, but not with the Milky Way halo.
A Redshift Survey of the Nearby Galaxy Cluster A2107: Global Rotation of the Cluster and Its Connection to Large-scale Structures in the Universe
Authors: Song Hyunmi , Hwang Ho Seong , Park Changbom , Smith Rory , Einasto Maret 
Published: December 2018

Abstract
We study the rotational motion of the galaxy cluster A2107 at redshift z = 0.04 and its connection to nearby large-scale structures using a large amount of spectroscopic redshift data. By combining 978 new redshifts from the MMT/Hectospec observations with data in the literature, we construct a large sample of 1968 galaxies with measured redshifts at clustercentric radius R < 60′. Our sample has high (80%) and spatially uniform completeness at r-band apparent magnitude

. We first apply the caustic method to the sample and identify 285 member galaxies of A2107 at R < 60′. Then the rotation amplitude and the position angle of the rotation axis are measured. We find that the member galaxies show strong global rotation at R < 20′ (v
rot/σ

v
∼ 0.6) with a significance of >3.8σ, which is confirmed by two independent methods. The rotation becomes weaker in outer regions. There are at least five filamentary structures that are connected to the cluster and that consist of known galaxy groups. These structures are smoothly connected to the cluster, which seem to be inducing the global rotation of the cluster through inflow of galaxies.
GD-1: The Relic of an Old Metal-poor Globular Cluster
Authors: Li 李 Guang-Wei 广伟 , Yanny Brian , Wu Yue 
Published: December 2018

Abstract
Combining data from Gaia DR2, SDSS DR14, and LAMOST DR6, we update the fit to model of the properties of the stellar stream GD-1 and find that it has an age of ∼13 Gyr, [Fe/H] of −2.2 ± 0.12, and a distance from the Sun of ∼8 kpc. We tabulate six-dimensional (6D) phase-space fiducial points along the GD-1 stream orbit over a 90° arc. The fitted orbit shows that the stream has an eccentricity e ∼ 0.3, perigalacticon of 14.2 kpc, apogalacticon of 27.0 kpc, and inclination i ∼ 40°. There is evidence along the arc for four candidate stellar overdensities, one candidate gap, two candidate stellar underdensities, and that the stream is cut off at ϕ
1 ∼ 2° (in the stream-aligned (ϕ
1, ϕ
2) coordinate system of Koposov et al.). The spur originating at ϕ
1 ∼ −40° implies stars were pulled away from the stream trace by an encounter (potentially a dark matter subhalo). The narrowest place (FWHM ∼ 44.6 pc) of the GD-1 trace is at (ϕ
1, ϕ
2

c
) ∼ (−14°, 0.°15), which is ∼(178.°18, 52.°19) in (R.A., decl.), where the progenitor is possibly located. We also find six blue horizontal branch and 10 blue stragglers spectroscopic stars in the GD-1 stream.
A Centimeter-wave Study of Methanol and Ammonia Isotopologues in Sgr B2(N): Physical and Chemical Differentiation between Two Hot Cores
Authors: Mills E. A. C. , Corby J. , Clements A. R. , Butterfield N. , Jones P. A. , Cunningham M. R. , Ott J. 
Published: December 2018

Abstract
We present new radio-frequency interferometric maps of emission from the 14NH3, 15NH3, and NH2D isotopologues of ammonia and the 12CH3OH and 13CH3OH isotopologues of methanol toward Sgr B2(N). With a resolution of ∼3″ (0.1 pc), we are able to spatially resolve emission from two hot cores in this source and separate it from absorption against the compact H ii regions in this area. The first (N1) is the well-known v = 64 km s−1 core, and the second (N2) is a core 6″ to the north at v = 73 km s−1. Using emission from 15NH3 and hyperfine satellites of 14NH3 metastable transitions, we estimate the 14NH3 column densities of these sources and compare them to those of NH2D. We find that the ammonia deuteration fraction of N2 is roughly 10–20 times higher than that in N1. We also measure an [15NH3/14NH3] abundance ratio that is apparently 2–3 times higher in N2 than in N1, which could indicate a correspondingly higher degree of nitrogen fractionation in N2. In addition, we find that N2 has a factor of 7 higher methanol abundance than N1. Together, these abundance signatures suggest that N2 is a younger source, for which species characteristic of grain chemistry at low temperatures are currently being actively liberated from ice mantles and have not yet reached chemical equilibrium in the warm gas phase. The high D abundance and possible high 15N abundance in NH3 found in N2 are interesting for studying the potential interstellar origin of abundances in primitive solar system material.
Detecting Radio AGN Signatures in Red Geysers
Authors: Roy Namrata , Bundy Kevin , Cheung Edmond , Rujopakarn Wiphu , Cappellari Michele , Belfiore Francesco , Yan Renbin , Heckman Tim , Bershady Matthew , Greene Jenny , Westfall Kyle , Drory Niv , Rubin Kate , Law David , Zhang Kai , Gelfand Joseph , Bizyaev Dmitry , Wake David , Masters Karen , Thomas Daniel , Li Cheng , Riffel Rogemar A. 
Published: December 2018

Abstract
A new class of quiescent galaxies harboring possible AGN-driven winds has been discovered using spatially resolved optical spectroscopy from the ongoing SDSS-IV MaNGA survey. These galaxies, termed “red geysers,” constitute 5%–10% of the local quiescent population and are characterized by narrow bisymmetric patterns in ionized gas emission features. Cheung et al. argued that these galaxies host large-scale AGN-driven winds that may play a role in suppressing star formation at late times. In this work, we test the hypothesis that AGN activity is ultimately responsible for the red geyser phenomenon. We compare the nuclear radio activity of the red geysers to a matched control sample with similar stellar mass, redshift, rest-frame NUV − r color, axis ratio, and presence of ionized gas. We have used the 1.4 GHz radio continuum data from the VLA FIRST survey to stack the radio flux from the red geyser and control samples. In addition to a three times higher FIRST detection rate, we find that red geysers have a 5σ higher level of average radio flux than control galaxies. After restricting to rest-frame NUV − r color >5 and checking mid-IR WISE photometry, we rule out star formation contamination and conclude that red geysers are associated with more active AGNs. Red geysers and a possibly related class with disturbed Hα emission account for 40% of all radio-detected red galaxies with log (M
⋆/M
⊙) < 11. Our results support a picture in which episodic AGN activity drives large-scale, relatively weak ionized winds that may provide a feedback mechanism for many early-type galaxies.
The Dynamical Behavior of Reconnection-driven Termination Shocks in Solar Flares: Magnetohydrodynamic Simulations
Authors: Shen Chengcai , Kong Xiangliang , Guo Fan , Raymond John C. , Chen Bin 
Published: December 2018

Abstract
In eruptive solar flares, termination shocks (TSs), formed when high-speed reconnection outflows collide with closed dense flaring loops, are believed to be one of the possible candidates for plasma heating and particle acceleration. In this work, we perform resistive magnetohydrodynamic simulations in a classic Kopp–Pneuman flare configuration to study the formation and evolution of TSs, and we analyze in detail the dynamic features of TSs and variations of the shock strength in space and time. This research focuses on the fast-reconnection phase when plasmoids form and produce small-scale structures inside the flare current sheet. It is found that the TS emerges once the downward outflow colliding with closed magnetic loops becomes supermagnetosonic and immediately becomes highly dynamical. The morphology of a TS can be flat, oblique, or curved depending on the detailed interactions between the outflows/plasmoids and the highly dynamic plasma in the loop-top region. The TS becomes weaker when a plasmoid is crossing through, or may even be destroyed by well-developed plasmoids and then reconstructed above the plasmoids. We also perform detailed statistical analysis on important physical quantities along and across the shock front. The density and temperature ratios range from 1 to 3 across the TS front, and the pressure ratio typically has larger values up to 10. We show that weak guide fields do not strongly affect the Mach number and compression ratios, and the TS length becomes slightly larger in the case with thermal conduction.
Dust Polarization toward Embedded Protostars in Ophiuchus with ALMA. II. IRAS 16293-2422
Authors: Sadavoy Sarah I. , Myers Philip C. , Stephens Ian W. , Tobin John , Kwon Woojin , Segura-Cox Dominique , Henning Thomas , Commerçon Benoît , Looney Leslie 
Published: December 2018

Abstract
We present high-resolution (∼35 au) ALMA Band 6 1.3 mm dust polarization observations of IRAS 16293. These observations spatially resolve the dust polarization across the two protostellar sources and toward the filamentary structures between them. The dust polarization and inferred magnetic field have complicated structures throughout the region. In particular, we find that the magnetic field is aligned parallel to three filamentary structures. We characterize the physical properties of the filamentary structure that bridges IRAS 16293A and IRAS 16293B and estimate a magnetic field strength of 23–78 mG using the Davis-Chandrasekhar-Fermi method. We construct a toy model for the bridge material assuming that the young stars dominate the mass and gravitational potential of the system. We find that the expected gas flow to each star is of comparable order to the Alfvén speed, which suggests that the field may be regulating the gas flow. We also find that the bridging material should be depleted in ∼103 yr. If the bridge is part of the natal filament that formed the stars, then it must have accreted new material. Alternatively, the bridge could be a transient structure. Finally, we show that the 1.3 mm polarization morphology of the optically thick IRAS 16293B system is qualitatively similar to dust self-scattering. Based on similar polarization measurements at 6.9 mm, we propose that IRAS 16293B has produced a substantial population of large dust grains with sizes between 200 and 2000 μm.
Determining the Core Radio Luminosity Function of Radio AGNs via Copula
Authors: Yuan Zunli , Wang Jiancheng , Worrall D. M. , Zhang Bin-Bin , Mao Jirong 
Published: December 2018

Abstract
The radio luminosity functions (RLFs) of active galactic nuclei (AGNs) are traditionally measured based on total emission, which does not reflect the current activity of the central black hole. The increasing interest in compact radio cores of AGNs motivates determination of the RLF based on core emission (i.e., core RLF). In this work we have established a large sample (totaling 1207) of radio-loud AGNs, mainly consisting of radio galaxies (RGs) and steep-spectrum radio quasars (SSRQs). Based on the sample, we explore the relationship between core luminosity (L

c
) and total luminosity (L

t
) via a powerful statistical tool called “Copula.” The conditional probability distribution

is obtained. We derive the core RLF as a convolution of

with the total RLF that was determined by previous work. We relate the separate RG and SSRQ core RLFs via a relativistic beaming model and find that SSRQs have an average Lorentz factor of

, and that most are seen within 8° ≲ θ ≲ 45° of the jet axis. Compared with the total RLF, which is mainly contributed by extended emission, the core RLF shows a very weak luminosity-dependent evolution, with the number density peaking around z ∼ 0.8 for all luminosities. Differences between core and total RLFs can be explained in a framework involving a combination of density and luminosity evolutions where the cores have significantly weaker luminosity evolution than the extended emission.
COLOSSUS: A Python Toolkit for Cosmology, Large-scale Structure, and Dark Matter Halos
Authors: Diemer Benedikt 
Published: December 2018

Abstract
This paper introduces Colossus, a public, open-source python package for calculations related to cosmology, the large-scale structure (LSS) of matter in the universe, and the properties of dark matter halos. The code is designed to be fast and easy to use, with a coherent, well-documented user interface. The cosmology module implements Friedman–Lemaitre–Robertson–Walker cosmologies including curvature, relativistic species, and different dark energy equations of state, and provides fast computations of the linear matter power spectrum, variance, and correlation function. The LSS module is concerned with the properties of peaks in Gaussian random fields and halos in a statistical sense, including their peak height, peak curvature, halo bias, and mass function. The halo module deals with spherical overdensity radii and masses, density profiles, concentration, and the splashback radius. To facilitate the rapid exploration of these quantities, Colossus implements more than 40 different fitting functions from the literature. I discuss the core routines in detail, with particular emphasis on their accuracy. Colossus is available at bitbucket.org/bdiemer/colossus.
Testing the ABS Method with the Simulated Planck Temperature Maps
Authors: Yao Jian , Zhang Le , Zhao Yuxi , Zhang Pengjie , Santos Larissa , Zhang Jun 
Published: December 2018

Abstract
In this study, we apply the Analytical method of Blind Separation (ABS) of the cosmic microwave background (CMB) from foregrounds to estimate the CMB temperature power spectrum from multi-frequency microwave maps. We test the robustness of the ABS estimator and assess the accuracy of the power spectrum recovery using realistic simulations based on the seven-frequency Planck data, including various frequency-dependent and spatially varying foreground components (synchrotron, free–free, thermal dust, and anomalous microwave emission), as well as an uncorrelated Gaussian-distributed instrumental noise. Considering no prior information about the foregrounds, the ABS estimator can analytically recover the CMB power spectrum over almost all scales with less than 0.5% error for maps where the Galactic plane region (

) is masked out. To further test the flexibility and effectiveness of the ABS approach in a variety of situations, we apply the ABS to the simulated Planck maps in three cases: (1) without any mask, (2) imposing a two-times-stronger synchrotron emission, and (3) including only the Galactic plane region (

) in the analysis. In such extreme cases, the ABS approach can still provide an unbiased estimate of band powers at the level of 1 μK2 on average over all ℓ ranges, and the recovered powers are consistent with the input values within 1σ for most ℓ bins.
Autismes et processus adolescent
Authors: Chocron Michael , Krieger-Denou Hélène 
Published: December 2018

Dans le cadre des autismes peu de travaux se sont intéressés jusqu’à présent à essayer de caractériser comment le processus adolescent agit sur ces sujets. Dans cet article, nous proposons une lecture de certains concepts fondamentaux issus de l’œuvre de Freud et Philippe Gutton concernant l’adolescence à l’aune des connaissances concernant l’autisme en se basant sur les travaux de G. Haag, R. Roussillon, D. Meltzer, M. Rhode et D. Anzieu qui permettent d’appréhender le fonctionnement archaïque.
Canguilhem avec Goldstein : De la normativité de la vie à la normativité de la connaissance
Authors: Moya Diez Ivan 
Published: December 2018

Dans sa thèse de médecine de 1943 sur le normal et le pathologique, Georges Canguilhem se sert largement des idées de Kurt Goldstein lorsqu’il définit la normalité comme la capacité de l’organisme à créer de nouvelles normes de vie dans un débat polarisé avec son milieu. Pourtant, il déclara ensuite que les conceptions de Goldstein avaient constitué pour lui un « encouragement et non une inspiration ». Les archives personnelles de Canguilhem nous permettent effectivement de considérer le rapport de Canguilhem à Goldstein comme une convergence plutôt que comme une influence mais surtout, l’usage que Canguilhem fait de Goldstein nous permet de mieux saisir la portée de ses propres idées. Nous interrogeons dans une première partie la conception holiste de l’organisme de Goldstein, dans ses rapports à la gestalt-théorie et à Kant, conception qui se réfère au processus d’actualisation de l’essence de l’organisme dans son rapport avec le milieu. Ceci nous permet d’appréhender l’usage que fait Canguilhem de certains concepts et idées de Goldstein pour élaborer son propre concept de normativité vitale. Dans une deuxième partie, nous nous proposons de comprendre la manière dont Canguilhem pose le problème du rapport de la connaissance à la normativité vitale à partir de sa lecture des textes du neurologue allemand.
De la science des monstres : Canguilhem et la tératologie expérimentale d’Étienne Wolff
Authors: Vagelli Matteo 
Published: December 2018

Dans cet article nous souhaitons montrer comment la connaissance approfondie que Canguilhem avait de la tératologie expérimentale a contribué à ses analyses des concepts d’anomalie et d’anormalité. Dans la première partie de l’article, après avoir retracé l’intérêt de Canguilhem pour les travaux d’Étienne Wolff grâce à l’analyse des textes préparatoires de sa thèse de 1943, nous clarifions les conceptions canguilhémiennes concernant, d’abord, l’équivalence ontologique a priori de toute forme vivante, et, deuxièmement, la nécessité épistémologique « d’éclairer par la connaissance des formations monstrueuses celle des formations normales ». Dans la deuxième partie de l’article, nous nous concentrons sur les contributions spécifiques apportées par les pratiques expérimentales de Wolff aux réflexions canguilhémiennes sur les concepts de totalité d’un organisme vivant et d’irréversibilité des phénomènes vitaux. Nous terminons en observant les conséquences de la « révolution moléculaire » des années 1960 sur la tératologie et en tirant des conclusions plus générales sur la manière dont l’étude des monstres met en lumière certains des aspects méthodologiques propres à l’épistémologie historique.
Randomized Controlled Trial Evaluating Aerobic Training and Common Sport-Related Concussion Outcomes in Healthy Participants
Authors: Teel Elizabeth F. , Register-Mihalik Johna K. , Appelbaum Lawrence Gregory , Battaglini Claudio L. , Carneiro Kevin A. , Guskiewicz Kevin M. , Marshall Stephen W. , Mihalik Jason P. 
Published: December 2018

ContextAerobic exercise interventions are increasingly being prescribed for concussion rehabilitation, but whether aerobic training protocols influence clinical concussion diagnosis and management assessments is unknown.ObjectiveTo investigate the effects of a brief aerobic exercise intervention on clinical concussion outcomes in healthy, active participants.DesignRandomized controlled clinical trial.SettingLaboratory.Patients or Other ParticipantsHealthy (uninjured) participants (n = 40) who exercised ≥3 times/week.Intervention(s)Participants were randomized into the acute concussion therapy intervention (ACTIVE) training or nontraining group. All participants completed symptom, cognitive, balance, and vision assessments during 2 test sessions approximately 14 days apart. Participants randomized to ACTIVE training completed six 30-minute exercise sessions that progressed from 60% to 80% of individualized maximal oxygen consumption (V˙o2max) across test sessions, while the nontraining group received no intervention.Main Outcome Measure(s)The CNS Vital Signs standardized scores, Vestibular/Ocular Motor Screening near-point convergence distance (cm), and Graded Symptom Checklist, Balance Error Scoring System, and Standardized Assessment of Concussion total scores.ResultsAn interaction effect was found for total symptom score (P = .01); the intervention group had improved symptom scores between sessions (session 1: 5.1 ± 5.8; session 2: 1.9 ± 3.6). Cognitive flexibility, executive functioning, reasoning, and total symptom score outcomes were better but composite memory, verbal memory, and near-point convergence distance scores were worse at the second session (all P values &lt; .05). However, few changes exceeded the 80% reliable change indices calculated for this study, and effect sizes were generally small to negligible.ConclusionsA brief aerobic training protocol had few meaningful effects on clinical concussion assessment in healthy participants, suggesting that current concussion-diagnostic and -assessment tools remain clinically stable in response to aerobic exercise training. This provides normative data for future researchers, who should further evaluate the effect of ACTIVE training on clinical outcomes among concussed populations.Trial Registration NumberClinicalTrials.gov: NCT02872480