bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultra-short-period Planets from Secular Chaos
Authors: Petrovich Cristobal , Deibert Emily , Wu Yanqin 
Published: April 2019

Abstract
Over 100 rocky planets orbiting Sun-like stars in very short orbital periods (≲1 day) have been discovered by the Kepler mission. The origin of these planets, known as ultra-short-period (USP) planets, remains elusive. Here, we propose that most of these planets, originally at periods of ∼5–10 days, reach their current orbits via high-eccentricity migration. In a scaled-down version of the dynamics that may have been experienced by their high-mass analogs, the hot Jupiters, these planets reach high eccentricities via chaotic secular interactions with their companion planets and then undergo orbital circularization due to dissipation from tides raised on the planet. This proposal is motivated by the following observations: planetary systems observed by Kepler often contain several super-Earths with non-negligible eccentricities and inclinations, possibly extending beyond ∼au distances; by contrast, only a small fraction of USP planets have known transiting companions, which are generally not closely spaced, and we argue that most of them should have companions with periods ≳10 days. The proposed scenario naturally explains the observation that most USP planets have significantly more distant transiting companions compared to their counterparts at slightly longer periods (1–3 days). Our model predicts that USP planets should have: (i) spin–orbit angles, and inclinations relative to outer planets, in the range of ∼10–50°; (ii) several outer planetary companions extending beyond ∼1 au distances. Both of these predictions may be tested by TESS and its follow-up observations.
Modeling the Altitude Distribution of Meteor Head Echoes Observed with HPLA Radars: Implications for the Radar Detectability of Meteoroid Populations
Authors: Swarnalingam N. , Janches D. , Carrillo-Sanchez J. D. , Pokorny P. , Plane J. M. C. , Sternovsky Z. , Nesvorny D. 
Published: April 2019

Abstract
The altitude distribution of meteors detected by a radar is sensitive to the instrument’s response function and can thus provide insight into the physical processes involved in radar measurements. This, in turn, can be used to determine the rate of ablation and ionization of the meteoroids and ultimately the input flux on Earth. In this work, we model the radar meteor head echo altitude distribution for three High Power and Large Aperture radar systems, by considering meteoroid populations from the main cometary family sources. In this simulation, we first use the results of a dynamical model of small meteoroids impacting Earth’s upper atmosphere to model the incoming mass, velocity, and entry angular distributions. We then combine these with the Chemical Ablation Model and establish the meteoroid ionization rates as a function of mass, velocity, and entry angle in order to determine the altitude at which these radars should detect the produced meteors and the portion of produced meteors from each population that are detected by these radars. We explore different sizes of head plasma as well as the possible effects on radar scattering of the head echo aspect sensitivity. We find that the modeled altitude distributions are generally in good agreement with measurements, particularly for ultra-high-frequency radars. In addition, our results indicate that the number of particles from Jupiter Family Comets (JFCs) required to fit the observations is lower than predicted by astronomical models. It is not clear yet if this discrepancy is due to the overprediction of JFC meteoroids by dynamical models or due to unaccounted physical processes in the treatment of ablation, ionization, and detections of meteoroids as they pass through Earth’s atmosphere.
Proper Motions of Milky Way Ultra-faint Satellites with Gaia DR2 × DES DR1
Authors: Pace Andrew B. , Li Ting S. 
Published: April 2019

Abstract
We present a new, probabilistic method for determining the systemic proper motions of Milky Way (MW) ultra-faint satellites in the Dark Energy Survey (DES). We utilize the superb photometry from the first public data release (DR1) of the DES to select candidate members and cross-match them with the proper motions from the Gaia DR2. We model the candidate members with a mixture model (satellite and MW) in spatial and proper motion space. This method does not require prior knowledge of satellite membership and can successfully determine the tangential motion of 13 DES satellites. With our method, we present measurements of the following satellites: Columba I, Eridanus III, Grus II, Phoenix II, Pictor I, Reticulum III, and Tucana IV. This is the first systemic proper motion measurement for several of these satellites, and the majority lack extensive spectroscopic follow-up studies. We compare these to the predictions of Large Magellanic Cloud satellites and the vast polar structure. With the high-precision DES photometry, we conclude that most of the newly identified member stars are very metal-poor ([Fe/H] ≲ −2), similar to other ultra-faint dwarf galaxies, while Reticulum III is likely more metal-rich. We also find potential members in the following satellites that might indicate their overall proper motion: Cetus II, Kim 2, and Horologium II. However, due to the small number of members in each satellite, spectroscopic follow-up observations are necessary to determine the systemic proper motion in these satellites.
The Population of Eccentric Binary Black Holes: Implications for mHz Gravitational-wave Experiments
Authors: Fang Xiao , Thompson Todd A. , Hirata Christopher M. 
Published: April 2019

Abstract
The observed binary black hole (BBH) mergers indicate a large Galactic progenitor population continuously evolving from large orbital separations and low gravitational-wave (GW) frequencies to the final merger phase. We investigate the equilibrium distribution of BBHs in the Galaxy. Given the observed BBH merger rate, we contrast the expected number of systems radiating in the low-frequency 0.1–10 mHz GW band under two assumptions: (1) that all merging systems originate from near-circular orbits, as may be indicative of isolated binary evolution, and (2) that all merging systems originate at very high eccentricity, as predicted by models of dynamically formed BBHs and triple and quadruple systems undergoing Lidov–Kozai eccentricity oscillations. We show that the equilibrium number of systems expected at every frequency is higher in the eccentric case (2) than in the circular case (1) by a factor of ≃2–15. This follows from the fact that eccentric systems spend more time than circular systems radiating in the low-frequency GW bands. The GW emission comes in pulses at periastron separated by the orbital period, which may be days to years. For a LISA-like sensitivity curve, we show that if eccentric systems contribute significantly to the observed merger rate, then ≃10 eccentric systems should be seen in the Galaxy.
Probing the Jet Turnover Frequency Dependence on Black Hole Mass and Mass Accretion Rate
Authors: Hammerstein Erica , Gültekin Kayhan , King Ashley 
Published: April 2019

Abstract
We have examined a sample of 13 sub-Eddington supermassive black holes hosted by galaxies spanning a variety of morphological classifications to further understand the empirical fundamental plane of black hole activity. This plane describes black holes from stellar-mass to supermassive and relates the mass of an accreting black hole and its radio and X-ray luminosities. A key factor in studying the fundamental plane is the turnover frequency, i.e., the frequency at which the radio continuum emission becomes optically thin. We measured this turnover frequency using new Very Large Array observations combined, when necessary, with archival Chandra observations. Radio observations are in the range of 5–40 GHz across four frequency bands in B configuration, giving high spatial resolution to focus on the core emission. We use Markov chain Monte Carlo methods to fit the continuum emission in order to find the turnover frequency. After testing for correlations, the turnover frequency does not display a significant dependence on either the mass or mass accretion rate, indicating that more complicated physics than simple scaling and optical depth effects are at play, as has been suggested by recent theoretical work.
Desorption Kinetics and Binding Energies of Small Hydrocarbons
Authors: Behmard Aida , Fayolle Edith C. , Graninger Dawn M. , Bergner Jennifer B. , Martín-Doménech Rafael , Maksyutenko Pavlo , Rajappan Mahesh , Öberg Karin I. 
Published: April 2019

Abstract
Small hydrocarbons are an important organic reservoir in protostellar and protoplanetary environments. Constraints on desorption temperatures and binding energies of such hydrocarbons are needed for accurate predictions of where these molecules exist in the ice versus gas phase during the different stages of star and planet formation. Through a series of temperature programmed desorption experiments, we constrain the binding energies of 2- and 3-carbon hydrocarbons (C2H2—acetylene, C2H4—ethylene, C2H6—ethane, C3H4—propyne, C3H6—propene, and C3H8—propane) to 2200–4200 K in the case of pure amorphous ices, to 2400–4400 K on compact amorphous H2O, and to 2800–4700 K on porous amorphous H2O. The 3-carbon hydrocarbon binding energies are always larger than the 2-carbon hydrocarbon binding energies. Within the 2- and 3-carbon hydrocarbon families, the alkynes (i.e., least-saturated) hydrocarbons exhibit the largest binding energies, while the alkane and alkene binding energies are comparable. Binding energies are ∼5%–20% higher on water ice substrates compared to pure ices, which is a small increase compared to what has been measured for other volatile molecules such as CO and N2. Thus in the case of hydrocarbons, H2O has a less pronounced effect on sublimation front locations (i.e., snowlines) in protoplanetary disks.
A Confined Partial Eruption of Double-decker Filaments
Authors: Zheng Ruisheng , Yang Shuhong , Rao Changhui , Liu Yangyi , Zhong Libo , Wang Bing , Song Hongqiang , Li Zhen , Chen Yao 
Published: April 2019

Abstract
Filament eruptions, one of the most energetic explosions on the Sun, release large quantities of magnetized plasma into the interplanetary space. Hence, the understanding of the initiation and evolution of filament eruptions can provide broader implications for space weather and geospace climate. Here, we present a confined partial eruption of double-decker structure that consisted of two vertically separated filaments on 2016 April 16. Only the upper filament erupted, and the eruption was closely associated with an episode of flux cancellation, surrounding transient brightenings, and unambiguous tether-cutting reconnections of the overlying sheared loops. However, the lower filament was nearly intact through the eruption. Interestingly, the erupting material moved along large-scale external loops and eventually arrived at remote sites, indicating a confined partial eruption. All the results show that the partial eruption involved two magnetic reconnections at least, and the bottom magnetic cancellation and internal tether-cutting reconnections between filaments both play critical roles in triggering the eruption. We conjecture that the newly formed low-lying loops due to tether-cutting reconnections and the flare loops resulting from the partial eruption likely contribute to maintaining the equilibrium of the lower filament. It is also suggested that the restriction of some large-scale external magnetic structures is crucial to turn the successful partial eruption into a confined event.
Fundamental Limitations on the Calibration of Redundant 21 cm Cosmology Instruments and Implications for HERA and the SKA
Authors: Byrne Ruby , Morales Miguel F. , Hazelton Bryna , Li Wenyang , Barry Nichole , Beardsley Adam P. , Joseph Ronniy , Pober Jonathan , Sullivan Ian , Trott Cathryn 
Published: April 2019

Abstract
Precise instrument calibration is critical to the success of 21 cm cosmology experiments. Unmitigated errors in calibration contaminate the Epoch of Reionization (EoR) signal, precluding a detection. Barry et al. characterized one class of inherent errors that emerge from calibrating to an incomplete sky model; however, it has been unclear if errors in the sky model affect the calibration of redundant arrays. In this paper, we show that redundant calibration is vulnerable to errors from sky model incompleteness even in the limit of perfect antenna positioning and identical beams. These errors are at a level that can overwhelm the EoR signal and prevent a detection in crucial power spectrum modes. Finally, we suggest error mitigation strategies with implications for the Hydrogen Epoch of Reionization Array and the Square Kilometre Array.
Climates of Warm Earth-like Planets. II. Rotational “Goldilocks” Zones for Fractional Habitability and Silicate Weathering
Authors: Jansen Tiffany , Scharf Caleb , Way Michael , Del Genio Anthony 
Published: April 2019

Abstract
Planetary rotation rate has a significant effect on atmospheric circulation, where the strength of the Coriolis effect in part determines the efficiency of latitudinal heat transport, altering cloud distributions, surface temperatures, and precipitation patterns. In this study, we use the ROCKE-3D dynamic ocean general circulation model to study the effects of slow rotations and increased insolations on the “fractional habitability” and silicate weathering rate of an Earth-like world. Defining the fractional habitability f

h
to be the percentage of a planet’s surface that falls in the 0 ≤ T ≤ 100 °C temperature regime, we find a moderate increase in f

h
with a 10% and 20% increase in insolation and a possible maximum in f

h
at sidereal day lengths between 8 and 32 times that of the modern Earth. By tracking precipitation and runoff, we further determine that there is a rotational regime centered on a 4 day period in which the silicate weathering rate is maximized and is particularly strongly peaked at higher overall insolations. Because of weathering’s integral role in the long-term carbonate–silicate cycle, we suggest that climate stability may be strongly affected by the anticipated rotational evolution of temperate terrestrial-type worlds and should be considered a major factor in their study. In light of our results, we argue that planetary rotation period is an important factor to consider when determining the habitability of terrestrial worlds.
A new Nigerian hunter snail species related to Ennea serrata d’Ailly, 1896 (Gastropoda, Pulmonata, Streptaxidae) with notes on the West African species attributed to Parennea Pilsbry, 1919
Authors: de Winter A.J. , de Gier Werner 
Published: April 2019

Enneanigeriensissp. n. is described from southeastern Nigeria on the basis of external and internal shell morphology. Following Pilsbry’s formal criteria of a single palatal fold and corresponding external furrow, the new species may be assigned to Parennea. Enneanigeriensissp. n. exhibits substantial similarity with E.serrata, a species from Cameroon, in the cylindrical shell shape, crenulate suture, and internal shell morphology, indicating that the two species are closely related. CT scanning confirmed the presence of only a single palatal fold in E.nigeriensissp. n. and two in E.serrata. In spite of this, the Nigerian species is provisionally assigned to Ennea rather than Parennea, suggesting that the characters used to define Ennea and Parennea are insufficient to delimit natural groups of species. The holotype of E.serrata is examined for the first time since its description in 1896 and a redescription of the species is provided based on the two shells hitherto known.
Study of the original specimens recorded as Ptychotrema (Parennea) sulciferum by Degner from Liberia reveals these to belong to Enneacf.thompsonae. The Nigerian shell recorded by van Bruggen as Ptychotrema (Parennea) aequatoriale proved to be a specimen of Enneacf.perforata. As a result, no species attributable to Parennea now appear to be known in West Africa; in contrast, numerous species are known from central and eastern Africa.
IFRS 8 : bilan de l’approche managériale de l’information sectorielle
Authors: Lenormand Gaëlle , Touchais Lionel 
Published: April 2019

Depuis 2009, l’IFRS 8 traite de l’information sectorielle en remplacement de l’IAS 14. Malgré les nombreuses critiques (manque d’homogénéité et de comparabilité, risque de comportements opportunistes) portant sur l’approche managériale adoptée par cette norme, l’IASB considère que l’IFRS 8 doit s’accompagner de données sectorielles plus utiles aux utilisateurs des comptes en apportant de l’information complémentaire liée à une segmentation plus proche du modèle d’affaires des groupes. Toutefois, les travaux réalisés sur l’IFRS 8 montrent qu’elle s’est accompagnée d’une relative stabilité du découpage sectoriel et d’une réduction significative des indicateurs publiés par secteur opérationnel. Quant aux résultats sur l’amélioration du contenu informationnel, ils s’avèrent très contrastés.
L’expert-comptable dans la culture populaire : une image ambiguë
Authors: Rocher Sébastien 
Published: April 2019

S’insérant dans la continuité des travaux sur l’image du professionnel comptable dans la culture populaire, cet article présente les résultats de l’étude de l’image de l’expert-comptable dans la bande dessinée francophone européenne. Il apparaît que ce personnage reste rare et n’apparaît qu’à partir du milieu des années 1990. Il ressort également que l’image caricaturale qui caractérise les premiers personnages d’expert-comptable tend à disparaître au fil du temps, au profit d’une image plus réaliste, plus proche de celle souhaitée par la profession comptable, mais également plus complexe et plus ambiguë. Enfin, un modèle d’analyse des personnages de comptables dans la culture populaire est proposé, construit sur la combinaison de deux dimensions : vie privée/vie professionnelle et isolement/communion.
Une théorie marxiste de la planification est-elle possible ?
Authors: Fondu Guillaume 
Published: April 2019

Ce texte tente de ressaisir les principaux enjeux théoriques liés à la notion de planification dans le marxisme, notion irréductible à une simple technique de gestion et incluant un projet théorique et politique qui devait répondre point par point au paradigme libéral. Après un bref rappel de l’histoire de ce projet, le texte aborde l’opposition entre les deux paradigmes à travers trois thèmes centraux, le sujet, l’ordre social, et les institutions qui le matérialisent. Ces thèmes sont étudiés sous trois angles : leur lecture libérale, la critique qu’en fait Marx, et les questions qu’ils adressent à une théorie de la planification conséquente.
Parole de l’enfant, parole à l’enfant
Authors: Lenfant Carole 
Published: April 2019

Mère d’un garçon atteint d’une myopathie de Duchenne, l’auteur retrace la façon dont elle a construit un espace de dialogue avec son fils. Pour livrer une parole qui corresponde à son enfant et qui repose sur l’authenticité et la justesse des mots, il était nécessaire, pour elle, d’accepter ce qui leur arrivait. Dès le jour où le diagnostic fut posé, elle décida qu’elle ne laisserait pas la maladie ternir le bonheur de son fils et que ce qui comptait par-dessus tout était le fait d’être en vie pour pouvoir accueillir, accepter, et adapter, en fonction de l’évolution de la pathologie. Construire un espace de dialogue, inscrit dans la durée, repose sur l’établissement d’une confiance réciproque. Les questions doivent toutes être posées et trouver des réponses, mais par étapes, selon les caps à franchir. L’enfant nous guide et il ne s’agit pas d’anticiper sur ses questionnements.	L’auteur est certaine qu’il faut, aussi, parler de la maladie autour de soi. Il ne s’agit pas de banaliser la situation mais de la normaliser afin que son enfant se sente à la fois compris et considéré comme tout être dans ce monde, avec ses différences qui le rendent unique.
Ai-je mes maux à dire ?
Authors: Salmona Sarah 
Published: April 2019

L’enfant que j’étais et les grandes personnes qui m’entouraient avaient tous une manière particulière de se raconter la myopathie et il était parfois impossible de se comprendre.	Il y avait la parole scientifique, vérifiable, mesurable, dissécable qui ne s’embarrasse pas des émotions. Des mots que l’on note dans des comptes rendus médicaux mais qui sont parfois imprononçables pour un enfant et même souvent incompréhensibles. Et puis il y avait la parole du cœur, qui se passe de mots, parce qu’on n’ose l’avouer, parce que les parents veulent protéger leur enfant, parce qu’il est difficile pour un petit d’exprimer tout ce qu’il sent, tout ce qui se joue dans son corps et son esprit. Mais même dans le silence, tout parle, les regards, les corps, les décors car l’enfant s’interroge, interprète ce qu’on lui cache et ce sont parfois ses larmes qui coulent à la place des mots. Il a fallu que j’atteigne l’âge adulte pour réussir à faire parler la petite Sarah, et les mots, comme une énergie vitale, ont comblé un espace vide, trop longtemps oublié.
Identité, souci de soi et psychopathologie à l’adolescence
Authors: Rizet Clément 
Published: April 2019

Identité et appartenance sont souvent confondues et les distinguer permet de penser autrement la nécessaire question du « moment fécond » (Kαιpos) qu’est l’adolescence et de ses aléas éventuellement pathologiques. Une analyse de la notion d’identité introduira la réflexion, suivie d’une transition sur celle de continuité chère à Winnicott. Dans une double perspective existentielle et psychanalytique, cette question sera mise à l’épreuve de la psychose, qui est aux prises avec la rencontre de soi et de l’Autre, à l’aide d’un exemple clinique.
Ulysse, Cyclope, Sirènes
Authors: Prado de Oliveira Luiz Eduardo 
Published: April 2019

D’où vient la caricature de l’analyste silencieux ? Qu’est-ce que le silence implique en analyse ? À partir de deux figures légendaires évoquées par Lacan, de témoignages au sujet de Freud et de commentaires faits par Ferenczi, l’auteur examine quelques aspects de ces questions.
Pour une poétique de l’étranger, éloge de la non-identité
Authors: Germanos Besson Dina 
Published: April 2019

N’en déplaise à nos contemporains, relever l’enjeu de « l’étranger » semble être une de nos priorités actuelles, dans un monde où l’on voit, hélas, la montée de l’expression des identités exacerbées. Ainsi, cet article invite à percevoir l’étranger, cette figure tenant-hors , comme un remède à l’identité qui aliène. Mais tout se passe comme si le monde d’aujourd’hui, rêvant d’un univers homogène, ne voulait plus de l’étranger réduit désormais au rebut. Après avoir rapidement dégagé ce thème du corpus psychanalytique, nous analyserons l’aspect étranger de la langue, conçu ici comme un possible renouvellement. Cette étrangeté participe inévitablement de la résistance, puisque l’on s’insurge contre la langue préfabriquée. Et, c’est, justement, en faisant offense à la langue conformiste qu’on empêche toute stagnation et dissolution dans la masse.