bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polynomial Apodizers for Centrally Obscured Vortex Coronagraphs
Authors: Fogarty Kevin , Pueyo Laurent , Mazoyer Johan , N’Diaye Mamadou 
Published: November 2017

Abstract
Several coronagraph designs have been proposed over the last two decades to directly image exoplanets. Among these designs, vector vortex coronagraphs provide theoretically perfect starlight cancellation along with small inner working angles when deployed on telescopes with unobstructed pupils. However, current and planned space missions and ground-based extremely large telescopes present complex pupil geometries, including large central obscurations caused by secondary mirrors, which prevent vortex coronagraphs from rejecting on-axis sources entirely. Recent solutions combining the vortex phase mask with a ring-apodized pupil have been proposed to circumvent this issue, but provide a limited throughput for vortex charges

. We present pupil plane apodizations for charge 2, 4, and 6 vector vortex coronagraphs that compensate for pupil geometries with circularly symmetric central obstructions caused by on-axis secondary mirrors. These apodizations are derived analytically and allow vortex coronagraphs to retain theoretically perfect nulling in the presence of obstructed pupils. For a charge 4 vortex, we design polynomial apodization functions assuming a grayscale apodizing filter that represent a substantial gain in throughput over the ring-apodized vortex coronagraph design, while for a charge 6 vortex, we design polynomial apodized vortex coronagraphs that have

total energy throughput for the entire range of central obscuration sizes studied. We propose methods for optimizing apodizations produced with either grayscale apodizing filters or shaped mirrors. We conclude by demonstrating how this design may be combined with apodizations numerically optimized for struts and primary mirror segment gaps to design terrestrial exoplanet imagers for complex pupils.
Precise Masses in the WASP-47 System
Authors: Vanderburg Andrew , Becker Juliette C. , Buchhave Lars A. , Mortier Annelies , Lopez Eric , Malavolta Luca , Haywood Raphaëlle D. , Latham David W. , Charbonneau David , López-Morales Mercedes , Adams Fred C. , Bonomo Aldo Stefano , Bouchy François , Cameron Andrew Collier , Cosentino Rosario , Fabrizio Luca Di , Dumusque Xavier , Fiorenzano Aldo , Harutyunyan Avet , Johnson John Asher , Lorenzi Vania , Lovis Christophe , Mayor Michel , Micela Giusi , Molinari Emilio , Pedani Marco , Pepe Francesco , Piotto Giampaolo , Phillips David , Rice Ken , Sasselov Dimitar , Ségransan Damien , Sozzetti Alessandro , Udry Stéphane , Watson Chris 
Published: November 2017

Abstract
We present precise radial velocity observations of WASP-47, a star known to host a hot Jupiter, a distant Jovian companion, and, uniquely, two additional transiting planets in short-period orbits: a super-Earth in a ≈19 hr orbit, and a Neptune in a ≈9 day orbit. We analyze our observations from the HARPS-N spectrograph along with previously published data to measure the most precise planet masses yet for this system. When combined with new stellar parameters and reanalyzed transit photometry, our mass measurements place strong constraints on the compositions of the two small planets. We find that, unlike most other ultra-short-period planets, the inner planet, WASP-47 e, has a mass (6.83 ± 0.66

) and a radius (1.810 ± 0.027

) that are inconsistent with an Earth-like composition. Instead, WASP-47 e likely has a volatile-rich envelope surrounding an Earth-like core and mantle. We also perform a dynamical analysis to constrain the orbital inclination of WASP-47 c, the outer Jovian planet. This planet likely orbits close to the plane of the inner three planets, suggesting a quiet dynamical history for the system. Our dynamical constraints also imply that WASP-47 c is much more likely to transit than a geometric calculation would suggest. We calculate a transit probability for WASP-47 c of about 10%, more than an order of magnitude larger than the geometric transit probability of 0.6%.
Dynamical Evolution Induced by Planet Nine
Authors: Batygin Konstantin , Morbidelli Alessandro 
Published: November 2017

Abstract
The observational census of trans-Neptunian objects with semimajor axes greater than

exhibits unexpected orbital structure that is most readily attributed to gravitational perturbations induced by a yet-undetected, massive planet. Although the capacity of this planet to (i) reproduce the observed clustering of distant orbits in physical space, (ii) facilitate the dynamical detachment of their perihelia from Neptune, and (iii) excite a population of long-period centaurs to extreme inclinations is well-established through numerical experiments, a coherent theoretical description of the dynamical mechanisms responsible for these effects remains elusive. In this work, we characterize the dynamical processes at play from semi-analytic grounds. We begin by considering a purely secular model of orbital evolution induced by Planet Nine and show that it is at odds with the ensuing stability of distant objects. Instead, the long-term survival of the clustered population of long-period Kuiper Belt objects (KBOs) is enabled by a web of mean-motion resonances driven by Planet Nine. Then, by taking a compact-form approach to perturbation theory, we show that it is the secular dynamics embedded within these resonances that regulate the orbital confinement and perihelion detachment of distant KBOs. Finally, we demonstrate that the onset of large-amplitude oscillations of the orbital inclinations is accomplished through the capture of low-inclination objects into a high-order secular resonance, and we identify the specific harmonic that drives the evolution. In light of the developed qualitative understanding of the governing dynamics, we offer an updated interpretation of the current observational data set within the broader theoretical framework of the Planet Nine hypothesis.
The Horizontal Branch Population of NGC 1851 as Revealed by the Ultraviolet Imaging Telescope (UVIT)
Authors: Subramaniam Annapurni , Sahu Snehalata , Postma Joseph E. , Côté Patrick , Hutchings J. B. , Darukhanawalla N. , Chung Chul , Tandon S. N. , Rao N. Kameswara , George K. , Ghosh S. K. , Girish V. , Mohan R. , Murthy J. , Pati A. K. , Sankarasubramanian K. , Stalin C. S. , Choudhury S. 
Published: November 2017

Abstract
We present the UV photometry of the globular cluster NGC 1851 using images acquired with the Ultraviolet Imaging Telescope (UVIT) onboard the ASTROSAT satellite. Point-spread function fitting photometric data derived from images in two far-UV (FUV) filters and one near-UV (NUV) filter are used to construct color–magnitude diagrams (CMDs), in combination with HST and ground-based optical photometry. In the FUV, we detect only the bluest part of the cluster horizontal branch (HB); in the NUV, we detect the full extent of the HB, including the red HB, blue HB, and a small number of RR Lyrae stars. UV variability was detected in 18 RR Lyrae stars, and three new variables were also detected in the central region. The UV/optical CMDs are then compared with isochrones of different age and metallicity (generated using Padova and BaSTI models) and synthetic HB (using helium-enhanced Y
2 models). We are able to identify two populations among the HB stars, which are found to have either an age range of 10–12 Gyr, or a range in Y
ini of 0.23–0.28, for a metallicity of [Fe/H] = −1.2 to −1.3. These estimations from the UV CMDs are consistent with those from optical studies. The almost-complete sample of the HB stars tends to show a marginal difference in spatial/azimuthal distribution among the blue and red HB stars. Thus, this study showcases the capability of UVIT, with its excellent resolution and large field of view, to study the hot stellar population in Galactic globular clusters.
The Magnetar Model for Type I Superluminous Supernovae. I. Bayesian Analysis of the Full Multicolor Light-curve Sample with MOSFiT
Authors: Nicholl Matt , Guillochon James , Berger Edo 
Published: November 2017

AbstractWe use the new Modular Open Source Fitter for Transients to model 38 hydrogen-poor superluminous supernovae (SLSNe). We fit their multicolor light curves with a magnetar spin-down model and present posterior distributions of magnetar and ejecta parameters. The color evolution can be fit with a simple absorbed blackbody. The medians (1σranges) for key parameters are spin period 2.4 ms (1.2–4 ms), magnetic fieldG (G), ejecta mass 4.8(2.2–12.9), and kinetic energyerg (erg). This significantly narrows the parameter space compared to our uninformed priors, showing that although the magnetar model is flexible, the parameter space relevant to SLSNe is well constrained by existing data. The requirement that the instantaneous engine power is ∼1044erg at the light-curve peak necessitates either large rotational energy (ms), or more commonly that the spin-down and diffusion timescales be well matched. We find no evidence for separate populations of fast- and slow-declining SLSNe, which instead form a continuum in light-curve widths and inferred parameters. Variations in the spectra are explained through differences in spin-down power and photospheric radii at maximum light. We find no significant correlations between model parameters and host galaxy properties. Comparing our posteriors to stellar evolution models, we show that SLSNe require rapidly rotating (fastest 10%) massive stars (), which is consistent with their observed rate. High mass, low metallicity, and likely binary interaction all serve to maintain rapid rotation essential for magnetar formation. By reproducing the full set of light curves, our posteriors can inform photometric searches for SLSNe in future surveys.
The High-frequency Radio Emission of the Galactic Center Magnetar SGR J1745–29 during a Transitional Period
Authors: Gelfand Joseph D. , Ransom Scott , Kouveliotou Chryssa , Granot Jonathan , van der Horst Alexander J. , Zhang Guobao , Göğüş Ersin , Roberts Mallory S. E. , Ali Hend Al 
Published: November 2017

Abstract
The origin of the high-frequency radio emission detected from several magnetars is poorly understood. In this paper, we report the

∼
40

GHz

properties of SGR J1745−29 measured using Jansky Very Large Array (JVLA) and Robert C. Byrd Green Bank Telescope (GBT) observations between 2013 October 26 and 2014 May 31. Our analysis of a Q-band (45 GHz) GBT observation on 2014 April 10 resulted in the earliest detection of pulsed radio emission at high frequencies (

≳
20

GHz

); we found that the average pulse has a singly peaked profile with width

∼
75

ms

(∼2% of the

3.764

s

pulse period) and an average pulsed flux density of ∼100 mJy. We also detected very bright, short

(
<
10

ms
)

single pulses during ∼70% of this neutron star’s rotations, and the peak flux densities of these bright pulses follow the same log-normal distribution as measured at 8.5 GHz. Additionally, our analysis of contemporaneous JVLA observations suggest that its 41/44 GHz flux density varied between ∼1–4 mJy during this period, with a

∼
2
×

change observed on ∼20 minute timescales during a JVLA observation on 2014 May 10. Such a drastic change over short timescales is inconsistent with the radio emission resulting from a shock powered by the magnetar’s supersonic motion through the surrounding medium, but consistent with pulsed emission generated in its magnetosphere.
Numerical Simulations of Gaseous Disks Generated from Collisional Cascades at the Roche Limits of White Dwarf Stars
Authors: Kenyon Scott J. , Bromley Benjamin C. 
Published: November 2017

Abstract
We consider the long-term evolution of gaseous disks fed by the vaporization of small particles produced in a collisional cascade inside the Roche limit of a 0.6

white dwarf. Adding solids with radius

at a constant rate

into a narrow annulus leads to two distinct types of evolution. When

, the cascade generates a fairly steady accretion disk where the mass transfer rate of gas onto the white dwarf is roughly

and the mass in gas is

g, where T
0 is the temperature of the gas near the Roche limit and α is the dimensionless viscosity parameter. If

, the system alternates between high states with large mass transfer rates and low states with negligible accretion. Although either mode of evolution adds significant amounts of metals to the white dwarf photosphere, none of our calculations yield a vertically thin ensemble of solids inside the Roche limit. X-ray observations can place limits on the mass transfer rate and test this model for metallic line white dwarfs.
Microlensing of Extremely Magnified Stars near Caustics of Galaxy Clusters
Authors: Venumadhav Tejaswi , Dai Liang , Miralda-Escudé Jordi 
Published: November 2017

Abstract
Recent observations of lensed galaxies at cosmological distances have detected individual stars that are extremely magnified when crossing the caustics of lensing clusters. In idealized cluster lenses with smooth mass distributions, two images of a star of radius R approaching a caustic brighten as

and reach a peak magnification

before merging on the critical curve. We show that a mass fraction (

) in microlenses inevitably disrupts the smooth caustic into a network of corrugated microcaustics and produces light curves with numerous peaks. Using analytical calculations and numerical simulations, we derive the characteristic width of the network, caustic-crossing frequencies, and peak magnifications. For the lens parameters of a recent detection and a population of intracluster stars with

, we find a source-plane width of

for the caustic network, which spans

on the image plane. A source star takes

years to cross this width, with a total of

crossings, each one lasting for

with typical peak magnifications of

. The exquisite sensitivity of caustic-crossing events to the granularity of the lens-mass distribution makes them ideal probes of dark matter components, such as compact halo objects and ultralight axion dark matter.
Interstellar Pickup Ion Observations to 38 au
Authors: McComas D. J. , Zirnstein E. J. , Bzowski M. , Elliott H. A. , Randol B. , Schwadron N. A. , Sokół J. M. , Szalay J. R. , Olkin C. , Spencer J. , Stern A. , Weaver H. 
Published: November 2017

Abstract
We provide the first direct observations of interstellar H+ and He+ pickup ions in the solar wind from 22 to 38 au. We use the Vasyliunas and Siscoe model functional form to quantify the pickup ion distributions, and while the fit parameters generally lie outside their physically expected ranges, this form allows fits that quantify variations in the pickup H+ properties with distance. By ∼20 au, the pickup ions already provide the dominant internal pressure in the solar wind. We determine the radial trends and extrapolate them to the termination shock at ∼90 au, where the pickup H+ to core solar wind density reaches ∼0.14. The pickup H+ temperature and thermal pressure increase from 22 to 38 au, indicating additional heating of the pickup ions. This produces very large extrapolated ratios of pickup H+ to solar wind temperature and pressure, and an extrapolated ratio of the pickup ion pressure to the solar wind dynamic pressure at the termination shock of ∼0.16. Such a large ratio has profound implications for moderating the termination shock and the overall outer heliospheric interaction. We also identify suprathermal tails in the H+ spectra and complex features in the He+ spectra, likely indicating variations in the pickup ion history and processing. Finally, we discover enhancements in both H+ and He+ populations just below their cutoff energies, which may be associated with enhanced local pickup. This study serves to document the release and serves as a citable reference of these pickup ion data for broad community use and analysis.
More Consistent Antimalarial Intake in First 5 Years of Disease Is Associated with Better Prognosis in Patients with Systemic Lupus Erythematosus
Authors: Pakchotanon Rattapol , Gladman Dafna D. , Su Jiandong , Urowitz Murray B. 
Published: November 2017

Objective.To examine whether more consistent use of antimalarial agents (AM) leads to better results in systemic lupus erythematosus (SLE).Methods.From a longitudinal cohort study, we identified inception patients with a minimum of 5 years of followup. They were divided into 3 groups: patients who took AM > 60% of the time (group A), those who took AM < 60% of the time (group B), and those who did not receive AM (group C) during the first 5 years of followup. Outcomes included increase in Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI), flare, achieving low disease activity (LDA), adjusted mean Systemic Lupus Erythematosus Disease Activity Index 2000, cumulative doses of steroids (CMS), and AM-related retinal toxicity. Regression analysis models were constructed to identify predictors of the outcomes.Results.There were 459 patients identified: 236 (51.4%) in group A, 88 (19.2%) in group B, and 135 (29.4%) in group C. The changes in SDI, flare event, and CMS were significantly lower in group A, which more often achieved LDA. Multivariable analysis revealed that the patients in group A had a lower risk of increasing SDI and were more likely to achieve LDA at Year 5 compared to the patients in group C. Patients taking AM had lower CMS over the 5 years of followup. There was only 1 patient with AM-related retinal toxicity in each group.Conclusion.More consistent use of an AM over the first 5 years of SLE is associated with better outcomes.
The Sex Influence on Response to Tumor Necrosis Factor-α Inhibitors and Remission in Axial Spondyloarthritis
Authors: Lubrano Ennio , Perrotta Fabio Massimo , Manara Maria , D’Angelo Salvatore , Addimanda Olga , Ramonda Roberta , Punzi Leonardo , Olivieri Ignazio , Salvarani Carlo , Marchesoni Antonio 
Published: November 2017

Objective.The aim of this study was to evaluate the influence of sex on response to treatment and disease remission in patients with axial spondyloarthritis (axSpA).Methods.In this retrospective multicenter study, patients with axSpA, according to the Assessment of Spondyloarthritis international Society (ASAS) criteria for axSpA, and treated with adalimumab, etanercept, golimumab, or infliximab, were studied. We compared clinical characteristics, patient-reported outcomes, disease activity, function, and response to treatment in male and female patients with this disease.Results.Three hundred forty patients with axSpA (270 with ankylosing spondylitis, 19 with psoriatic arthritis with axial involvement, and 51 with nonradiographic axSpA) were studied. Male subjects had a significantly higher prevalence of grade IV sacroiliitis, higher levels of serum C-reactive protein, lower Maastricht Ankylosing Spondylitis Enthesitis Score, and fatigue when compared with females. Further, Kaplan-Meier survival curves showed that the rate of partial remission, ASAS40 response, and Ankylosing Spondylitis Disease Activity Score (ASDAS) major improvement, but not ASDAS inactive disease, were significantly lower in female patients.Conclusion.Our data suggest that female sex was associated with a lower rate of response to treatment and of disease remission in patients with axSpA treated with antitumor necrosis factor-α drugs.
L'innovation péricentrale dans l'industrie automobile : une gestion territoriale du risque de résistance au changement
Authors: Layan Jean-Bernard 
Published: November 2017

Résumé Depuis 30 ans émergent en périphérie immédiate des grands blocs régionaux de nouveaux pays constructeurs d’automobiles : Espagne, Mexique, République tchèque, Turquie etc. Les produits assemblés dans ces nouveaux espaces sont très souvent à la pointe de l’innovation et résultent surtout de process pionniers du point de vue organisationnel. L’existence de telles innovations organisationnelles en périphérie cadre mal avec les schémas traditionnels de l’analyse économique de la spécialisation internationale. Elle est en revanche plus compréhensible si l’on tient compte des aspects assurantiels des stratégies territoriales des constructeurs. Ceux-ci trouvent en périphérie des conditions favorables à la mise en place de changements organisationnels radicaux qui, en attaquant les statuts professionnels et en brouillant le cadre institutionnel du travail du personnel, risqueraient de se heurter à la résistance des salariés des usines centrales.
Les projets des agglomérations en matière de transport : représentations, projets, conflits et stratégie de « détournement » des réseaux
Authors: Reigner Hélène , Hernandez Frédérique 
Published: November 2017

Résumé La perspective adoptée ici nous a permis d’interroger la « panne de problématisation » (Offner, 2006) en matière de politiques locales de transport et de déplacement. Ce qui est mis en avant, c’est la non explicitation, par les agglomérations, de la globalité de leur projet, de leurs stratégies et de leurs priorités. En effet, mis côte à côte, la cartographie des multiples projets, à première vue épars, portés par les représentants des agglomérations (Aix-en-Provence, Aubagne et Grenoble) dessine un modèle cohérent bien qu’implicite, d’organisation des déplacements. Ce modèle générique d’organisation de la circulation permet aux agglomérations, en quête d’attractivité, de combiner, à leur échelle, accessibilité et protection vis-à-vis de l’automobile. Cependant, les agglomérations ne sont que partiellement maîtresses des réseaux qui traversent et structurent leur territoire. La concrétisation de ce modèle générique se heurte à d’autres représentations du territoire, et donc à d’autres représentations de l’usage des réseaux, portées par d’autres acteurs, agissant à d’autres échelles. Ainsi, l’enjeu central, bien qu’implicite, pour les représentants des agglomérations, consiste à construire une représentation de la ville et des réseaux de transport qu’elle accueille, qui accule les gestionnaires du réseau de type autoroutier à l’évolution urbaine de l’usage de ce réseau. Ce faisant, ces voiries peuvent être utilisées pour concrétiser le projet urbain des agglomérations. Plutôt que d’expliciter leur projet et ses implications à différentes échelles, au risque d’entrer en conflit frontal avec les autres gestionnaires du réseau, notamment l’État, les agglomérations développent des stratégies, projet par projet, de façon à « détourner » l’usage des réseaux dont elles ne sont pas gestionnaires. Au total, adopter une démarche compréhensive pour saisir le point de vue des agglomérations conduit à relativiser les critiques relatives aux politiques de transport et de déplacement tant en termes de déficit de problématisation que d’inefficacité des procédures.
Les frontières du « Ciel Unique Européen ».
Authors: Beyer Antoine 
Published: November 2017

Résumé L’article propose une géographie des frontières aériennes de l’Europe. Il montre comment celle-ci résulte de la combinaison d’options techniques et de données politiques. Dans un contexte d’intégration politique et sous la pression de trafics croissants, la partition traditionnelle de l’espace aérien évolue aujourd’hui dans l’UE selon des critères fonctionnels de moins en moins liés au tracé des frontières nationales. L’adoption en 2004 d’un nouveau cadre législatif communautaire et les efforts de coordination technique conduisent ainsi à transformer la carte du ciel. Les nouveaux dispositifs poussent au rapprochement des acteurs au sein d’instances de contrôle transnationales et partagées entre vols commerciaux et militaires. À terme, c’est l’ensemble de l’espace aérien continental qui devrait être redécoupé en régions fonctionnelles d’information en vol ou FAB ( Functional Airspace Blocks ), largement détachées des espaces nationaux au sol. Dans cette perspective, l’article cherche à répondre à deux interrogations : comprendre sur quelles bases se définissent les contours de ces régions aériennes émergentes, voir comment l’évolution de la notion de frontière aérienne peut éclairer les modalités de construction territoriale de l’UE.