bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Planetary Mass Uncertainties on Exoplanet Atmospheric Retrievals
Authors: Changeat Q. , Keyte L. , Waldmann I. P. , Tinetti G. 
Published: June 2020

Abstract
In current models used to interpret exoplanet atmospheric observations, the planetary mass is treated as a prior and is measured/estimated independently with external methods, such as radial velocity or transit timing variation techniques. This approach is necessary as available spectroscopic data do not have sufficient wavelength coverage and/or signal-to-noise to infer the planetary mass. We examine here whether the planetary mass can be directly retrieved from transit spectra as observed by future space observatories, which will provide higher quality spectra. More in general, we quantify the impact of mass uncertainties on spectral retrieval analyses for a host of atmospheric scenarios. Our approach is both analytical and numerical: we first use simple approximations to extract analytically the influence of each atmospheric/planetary parameter to the wavelength-dependent transit depth. We then adopt a fully Bayesian retrieval model to quantify the propagation of the mass uncertainty onto other atmospheric parameters. We found that for clear-sky, gaseous atmospheres the posterior distributions are the same when the mass is known or retrieved. The retrieved mass is very accurate, with a precision of more than 10%, provided the wavelength coverage and signal-to-noise ratio are adequate. When opaque clouds are included in the simulations, the uncertainties in the retrieved mass increase, especially for high altitude clouds. However, atmospheric parameters such as the temperature and trace-gas abundances are unaffected by the knowledge of the mass. Secondary atmospheres, expected to be present in many super-Earths, are more challenging due to the higher degree of freedom for the atmospheric main component, which is unknown. For broad wavelength range and adequate signal-to-noise observations, the mass can still be retrieved accurately and precisely if clouds are not present, and so are all the other atmospheric/planetary parameters. When clouds are added, we find that the mass uncertainties may impact substantially the retrieval of the mean molecular weight: an independent characterization of the mass would therefore be helpful to capture/confirm the main atmospheric constituent.
Magnetorotational Explosion of a Massive Star Supported by Neutrino Heating in General Relativistic Three-dimensional Simulations
Authors: Kuroda Takami , Arcones Almudena , Takiwaki Tomoya , Kotake Kei 
Published: June 2020

Abstract
We present results of three-dimensional (3D), radiation-magnetohydrodynamics (MHD) simulations of core-collapse supernovae in full general relativity (GR) with spectral neutrino transport. In order to study the effects of the progenitor’s rotation and magnetic fields, we compute three models, where the precollapse rotation rate and magnetic fields are included parametrically to a 20 M
⊙ star. While we find no shock revival in our two nonmagnetized models during our simulation times (∼500 ms after bounce), the magnetorotational (MR) driven shock expansion immediately initiates after bounce in our rapidly rotating and strongly magnetized model. We show that the expansion of the MR-driven flows toward the polar directions is predominantly driven by the magnetic pressure, whereas the shock expansion toward the equatorial direction is supported by neutrino heating. Our detailed analysis indicates that the growth of the so-called kink instability may hinder the collimation of jets, resulting in the formation of broader outflows. Furthermore, we find a dipole emission of lepton number, only in the MR explosion model, whose asymmetry is consistent with the explosion morphology. Although it is similar to the lepton number emission self-sustained asymmetry (LESA), our analysis shows that the dipole emission occurs not from the proto–neutron star convection zone but from above the neutrino sphere, indicating that it is not associated with the LESA. We also report several unique neutrino signatures, which are significantly dependent on both the time and the viewing angle, if observed, possibly providing rich information regarding the onset of the MR-driven explosion.
Kinematic Structure of the Galactic Center S Cluster
Authors: Ali Basel , Paul Daria , Eckart Andreas , Parsa Marzieh , Zajacek Michal , Peißker Florian , Subroweit Matthias , Valencia-S. Monica , Thomkins Lauritz , Witzel Gunther 
Published: June 2020

Abstract
We present a detailed analysis of the kinematics of 112 stars that mostly comprise the high-velocity S cluster and orbit the supermassive black hole Sgr A* at the center of the Milky Way. For 39 of them, orbital elements are known; for the remainder, we know proper motions. The distribution of the inclinations and the proper motion flight directions deviate significantly from a uniform distribution, which one expects if the orientation of the orbits are random. Across the central arcseconds, the S-cluster stars are arranged in two almost edge-on disks that are located at a position angle approximately ±45° with respect to the Galactic plane. The angular momentum vectors for stars in each disk point in both directions, i.e., the stars in a given disk rotate in opposite ways. The poles of this structure are located only about 25° from the line of sight. This structure may be the result of a resonance process that started with the formation of the young B-dwarf stars in the cluster about 6 Myr ago. Alternatively, it indicated the presence of a disturber at a distance from the center comparable to the distance of the compact stellar association IRS 13.
A Fully Self-consistent Model for Solar Flares
Authors: Ruan Wenzhi , Xia Chun , Keppens Rony 
Published: June 2020

Abstract
The “standard solar flare model” collects all physical ingredients identified by multiwavelength observations of our Sun: magnetic reconnection, fast particle acceleration, and the resulting emission at various wavelengths, especially in soft to hard X-ray channels. Its cartoon representation is found throughout textbooks on solar and plasma astrophysics and guides interpretations of unresolved energetic flaring events on other stars, accretion disks, and jets. To date, a fully self-consistent model that reproduces the standard scenario in all its facets is lacking, since this requires the combination of a large-scale, multidimensional magnetohydrodynamic (MHD) plasma description with a realistic fast electron treatment. Here we demonstrate such a novel combination, where MHD combines with an analytic fast electron model, adjusted to handle time-evolving, reconnecting magnetic fields and particle trapping. This allows us to study (1) the role of fast electron deposition in the triggering of chromospheric evaporation flows, (2) the physical mechanisms that generate various hard X-ray sources at chromospheric footpoints or looptops, and (3) the relationship between soft X-ray and hard X-ray fluxes throughout the entire flare loop evolution. For the first time, this self-consistent solar flare model demonstrates the observationally suggested relationship between flux swept out by the hard X-ray footpoint regions and the actual reconnection rate at the X-point, which is a major unknown in flaring scenarios. We also demonstrate that a looptop hard X-ray source can result from fast electron trapping.
The Effect of Seafloor Weathering on Planetary Habitability
Authors: Chambers John 
Published: June 2020

Abstract
Conventionally, a habitable planet is one that can support liquid water on its surface. Habitability depends on temperature, which is set by insolation and the greenhouse effect, due mainly to CO2 and water vapor. The CO2 level is increased by volcanic outgassing and decreased by continental and seafloor weathering. Here, I examine the climate evolution of Earth-like planets using a globally averaged climate model that includes both weathering types. Climate is sensitive to the relative contributions of continental and seafloor weathering, even when the total weathering rate is fixed. Climate also depends strongly on the dependence of seafloor weathering on CO2 partial pressure. Both these factors are uncertain. Earth-like planets have two equilibrium climate states: (i) an ice-free state where outgassing is balanced by both weathering types, and (ii) an ice-covered state where outgassing is balanced by seafloor weathering alone. The second of these has not been explored in detail before. For some planets, neither state exists, and the climate cycles between ice-covered and ice-free states. For some other planets, both equilibria exist, and the climate depends on the initial conditions. Insolation increases over time due to stellar evolution, so a planet usually encounters the ice-covered equilibrium first. Such a planet will remain ice covered, even if the ice-free state appears subsequently, unless the climate receives a large perturbation. The ice-covered equilibrium state covers a large fraction of phase space for Earth-like planets. Many planets conventionally assigned to a star’s habitable zone may be rendered uninhabitable as a result.
Significance of Gravitational Nonlinearities on the Dynamics of Disk Galaxies
Authors: Deur Alexandre , Sargent Corey , Terzić Balša 
Published: June 2020

Abstract
The discrepancy between the visible mass in galaxies or galaxy clusters and that inferred from their dynamics is well known. The prevailing solution to this problem is dark matter. Here we show that a different approach, one that conforms to both the current standard model of particle physics and general relativity (GR), explains the recently observed tight correlation between the galactic baryonic mass and the measured accelerations in the galaxy. Using direct calculations based on GR’s Lagrangian and parameter-free galactic models, we show that the nonlinear effects of GR make baryonic matter alone sufficient to explain this observation. Our approach also shows that a specific acceleration scale dynamically emerges. It agrees well with the value of the MOND acceleration scale.
Large Population of ALMA Galaxies at z > 6 with Very High [O iii] 88 μm to [C ii] 158 μm Flux Ratios: Evidence of Extremely High Ionization Parameter or PDR Deficit?
Authors: Harikane Yuichi , Ouchi Masami , Inoue Akio K. , Matsuoka Yoshiki , Tamura Yoichi , Bakx Tom , Fujimoto Seiji , Moriwaki Kana , Ono Yoshiaki , Nagao Tohru , Tadaki Ken-ichi , Kojima Takashi , Shibuya Takatoshi , Egami Eiichi , Ferrara Andrea , Gallerani Simona , Hashimoto Takuya , Kohno Kotaro , Matsuda Yuichi , Matsuo Hiroshi , Pallottini Andrea , Sugahara Yuma , Vallini Livia 
Published: June 2020

Abstract
We present our new Atacama Large Millimeter/Submillimeter Array (ALMA) observations targeting [O iii]88 μm, [C ii]158 μm, [N ii]122 μm, and dust-continuum emission for three Lyman break galaxies at z = 6.0293–6.2037, identified in the Subaru/Hyper Suprime-Cam survey. We clearly detect [O iii] and [C ii] lines from all of the galaxies at 4.3–11.8σ levels, and identify multi-band dust-continuum emission in two of the three galaxies, allowing us to estimate infrared luminosities and dust temperatures simultaneously. In conjunction with previous ALMA observations for six galaxies at z > 6, we confirm that all the nine z = 6–9 galaxies have high [O iii]/[C ii] ratios of

, ∼10 times higher than z ∼ 0 galaxies. We also find a positive correlation between the [O iii]/[C ii] ratio and the Lyα equivalent width (EW) at the ∼90% significance level. We carefully investigate physical origins of the high [O iii]/[C ii] ratios at z = 6–9 using Cloudy, and find that high density of the interstellar medium, low C/O abundance ratio, and the cosmic microwave background attenuation are responsible to only a part of the z = 6–9 galaxies. Instead, the observed high [O iii]/[C ii] ratios are explained by 10–100 times higher ionization parameters or low photodissociation region (PDR) covering fractions of 0%–10%, both of which are consistent with our [N ii] observations. The latter scenario can be reproduced with a density-bounded nebula with PDR deficit, which would enhance the Lyα, Lyman continuum, and

ionizing photons escape from galaxies, consistent with the [O iii]/[C ii]-Lyα EW correlation we find.
Particle Acceleration in Kink-unstable Jets
Authors: Davelaar Jordy , Philippov Alexander A. , Bromberg Omer , Singh Chandra B. 
Published: June 2020

Abstract
Magnetized jets in gamma-ray bursts and active galactic nuclei are thought to be efficient accelerators of particles; however, the process responsible for the acceleration is still a matter of active debate. In this work, we study the kink instability in non-rotating force-free jets using first-principle particle-in-cell simulations. We obtain similar overall evolution of the instability as found in magnetohydrodynamics simulations. The instability first generates large-scale current sheets, which at later times break up into small-scale turbulence. Reconnection in these sheets proceeds in the strong guide field regime, which results in a formation of steep power laws in the particle spectra. Later evolution shows heating of the plasma, which is driven by small-amplitude turbulence induced by the kink instability. These two processes energize particles due to a combination of ideal and non-ideal electric fields.
Shouts and Murmurs: Combining Individual Gravitational-wave Sources with the Stochastic Background to Measure the History of Binary Black Hole Mergers
Authors: Callister Tom , Fishbach Maya , Holz Daniel E. , Farr Will M. 
Published: June 2020

Abstract
One of the goals of gravitational-wave astronomy is to quantify the evolution of the compact binary merger rate with redshift. The redshift distribution of black hole mergers would offer considerable information about their evolutionary history, including their progenitor formation rate, the dependence of black hole formation on stellar metallicity, and the time delay distribution between formation and merger. Efforts to measure the binary redshift distribution are currently limited, however, by the detection range of existing instruments, which can individually resolve compact binary merger events only out to

. We present a novel strategy with which to measure the redshift distribution of binary black hole mergers well beyond the detection range of current instruments. By synthesizing direct detections of individually resolved mergers with indirect searches for the stochastic gravitational-wave background due to unresolved distant sources, we can glean information about the peak redshift, z

p
, at which the binary black hole merger rate attains its maximum, even when this redshift is beyond the detection horizon. Using data from Advanced LIGO and Virgo’s first and second observing runs, we employ this strategy to place joint constraints on z

p
and the slope α with which the binary merger rate increases at low redshifts, ruling out merger rates that grow faster than

and peak beyond

. Looking ahead, we project that approximately one year of observation with design-sensitivity Advanced LIGO will further break remaining degeneracies, enabling a direct measurement of the peak redshift of the binary black hole merger history.
Signatures of Helium Continuum in Cool Flare Loops Observed by SDO/AIA
Authors: Heinzel Petr , Schwartz Pavol , Lörinčík Juraj , Koza Július , Jejčič Sonja , Kuridze David 
Published: June 2020

Abstract
We present an analysis of off-limb cool flare loops observed by the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) during the gradual phase of SOL2017-09-10T16:06 X8.2-class flare. In the extreme-ultraviolet (EUV) channels starting from the 335 Å one, cool loops appear as dark structures against the bright loop arcade. These dark structures were precisely coaligned (spatially and temporally) with loops observed by Swedish Solar Telescope (SST) in emission lines of hydrogen and ionized calcium. A recently published semi-empirical model of cool loops based on SST observations serves to predict the level of hydrogen and helium recombination continua. The continua were synthesized using an approximate non-LTE (i.e., departures from local thermodynamic equilibrium) approach and theoretical spectra were then transformed to AIA signals. Comparison with signals detected inside the dark loops shows that only in AIA 211 Å channel the computed level of recombination continua is consistent with observations for some models, while in all other channels that are more distant from the continua edges the synthetic continuum is far too low. In analogy with on-disk observations of flares we interpret the surplus emission as due to numerous EUV lines emitted from hot but faint loops in front of the cool ones. Finally we briefly comment on failure of the standard absorption model when used for analysis of the dark-loop brightness.
Se remettre debout : marcher pour se sentir vivant
Authors: Le Breton David 
Published: June 2020

Dans les années 1950 en France, on marchait en moyenne sept kilomètres à pied par jour. Aujourd’hui, à peine trois cents mètres. La sédentarité est un souci majeur de la santé publique. Marcher, c’est reprendre corps dans son existence, retrouver une jouissance du temps, renouveler sa curiosité, se déconnecter pour se sentir vivant. C’est certes une pratique de santé, mais surtout une jouissance du monde.
Les inégalités sociales de santé dès la petite enfance : le rôle du sport
Authors: Nicaise Sarah , Mennesson Christine , Bertrand Julien 
Published: June 2020

S’appuyant sur une enquête menée auprès de 35 enfants âgé.e.s de 5 ou 6 ans et provenant de milieux sociaux variés, cet article s’intéresse aux relations entre pratiques sportives enfantines et inégalités sociales de santé. Malgré une forte diffusion des activités sportives pendant l’enfance, celles-ci restent toutefois inégalitaires et socialement distribuées. Selon la position sociale des parents, qui oriente des conduites éducatives, des représentations et des stratégies spécifiques, les enfants connaissent des expériences sportives différenciées qui participent à la formation de dispositions inégalement propices à la préservation d’un bon état de santé.
Faire de la recherche à propos/sur/avec/pour la Fédération française du sport adapté ?
Authors: Caby Isabelle , Marcellini Anne 
Published: June 2020

La Fédération française du sport adapté a officiellement mis en place en 2001 une commission nationale « Études et recherches » qui a été dirigée et animée par son vice-président, Roy Compte, jusqu’à son décès en 2017. La mission de cette commission est de dynamiser, soutenir et réaliser des recherches scientifiques sur les activités de la fédération. Pour cela, Roy Compte a su regrouper, pendant plus de quinze ans, des enseignants-chercheurs s’intéressant aux relations entre déficience intellectuelle et/ou troubles psychiques et pratique sportive. En présentant deux actions concrètes récentes menées au sein de cette commission, les auteurs dégagent les caractéristiques originales de ce dispositif de recherche inédit, élaboré au sein de la Fédération française du sport adapté.
Le placement sous surveillance électronique : quels impacts pour la santé et les pratiques sportives des condamnés ?
Authors: Dambuyant Mathias 
Published: June 2020

Cet article examine la double influence d’une peine sur les pratiques sportives : en termes de contraintes autant que d’opportunités. Pour les personnes condamnées au placement sous surveillance électronique, le bracelet peut apparaître autant comme un frein à la pratique sportive (à cause du stigmate d’apparaître avec un bracelet à la cheville) que comme une opportunité (sortir plus longtemps de son enfermement à domicile). Il en découle pour ces porteurs des ressentis du corps diminué ou augmenté, favorisant l’image de soi ou la santé de soi.
Le corps vieillissant, une ressource malgré tout. Réflexion sur la question de l’APA en institution
Authors: Salandini Nicolas 
Published: June 2020

Cet article offre une approche physique du corps vieillissant dans sa dimension holistique : ses aspects dynamiques, potentiels, préventifs. Il décrit les aspects théoriques et réglementaires et l’émergence de l’activité physique adaptée dans un établissement pour personnes âgées dépendantes.
Des adjectifs tough dans des langues sans construction Tough ? Le cas du russe
Authors: Paykin Katia , Van Peteghem Marleen 
Published: June 2020

En russe, les adjectifs signifiant ‹facile›, ‹difficile›, accompagnés d’un infinitif, ne présentent pas le phénomène de Object-to-Subject Raising (Rosenbaum 1967) puisque l’objet monté garde le cas qui lui est assigné par l’infinitif. La montée consiste donc en un simple changement de l’ordre des mots. Néanmoins, malgré l’absence d’une construction Tough sur le modèle de l’anglais, les adjectifs russes trudnyj ‹difficile›, legkij ‹facile›, etc. présentent des particularités par rapport aux autres adjectifs dans la mesure où ils sont les seuls à pouvoir entrer dans trois autres constructions : le passif réfléchi, le participe présent passif et une construction prépositionnelle en dlja ‹pour› + Ndéverbal. L’aptitude de ces adjectifs à entrer dans ces trois constructions confirme leur propension aux phénomènes de montée, due à leur affinité sémantique avec la modalité.
La construction Tough en arabe standard et en bulgare : une sémantique commune
Authors: Tayalati Fayssal , Mostrov Vassil 
Published: June 2020

Dans cet article sont comparées les constructions Tough de deux langues typologiquement très éloignées, l’arabe standard et le bulgare. Il sera montré que, malgré les différences morphosyntaxiques, ces constructions reposent sur le même mécanisme sémantique de double prédication que les grammairiens arabes appellent le ‹mode d’attribution indirect›. Les paraphrases par des structures possessives dans les deux langues permettent, en outre, de reconnaître à l’élément déverbal le statut de dimension – une sorte de partie abstraite très particulière (Van de Velde 2020 ce volume). Enfin, les auteurs posent la question de la ‹source› de la qualité dénotée par l’adjectif tough , en signalant quelques différences entre les deux langues au niveau des adjectifs modaux.
Discovering Trends of Mobile Learning Research Using Topic Modelling Approach
Authors: Hamzah Almed , Hidayatullah Ahmad Fathan , Persada Andhika Giri 
Published: June 2020

This paper reports a map of identified topics from mobile learning research. Mobile learning is an emerging paradigm in an educational context as its adoption in an educational institution is growing rapidly. The students are already using and familiar with it. The publications from the last ten years were examined. Two approaches were employed to identify themes, i.e. word cloud and Latent Dirichlet Allocation. The result shows that mobile learning research is shifting from the development into optimization paradigm. This research is beneficial for mobile learning literature to inform the researcher and practitioner in the mobile learning area in terms of research topic trend and therefore consider it as a basis for designing mobile learning system in the future.