bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lorentz Factor Evolution of an Expanding Jet Shell Observed in a Gamma-Ray Burst: Case Study of GRB 160625B
Authors: Lin Da-Bin , Lu Rui-Jing , Du Shen-Shi , Liu Tong , Wang Xiang-Gao , Liang En-Wei 
Published: October 2019

Abstract
The Lorentz factor of a relativistic jet and its evolution during the jet expansion are difficult to estimate, especially for the jets in gamma-ray bursts (GRBs). However, the Lorentz factor is related to the jet physics. Owing to the absorption of two-photon pair production (

), a high-energy spectral cutoff may appear in the radiation spectrum of GRBs. We search for such high-energy cutoffs in GRB 160625B, which is one of the brightest bursts in recent years. It is found that the high-energy spectral cutoff is obvious for the first pulse in the second emission episode of GRB 160625B (i.e., ∼186–192 s after the burst first trigger), which is smooth and well-shaped. Then, we estimate the Lorentz factor and radiation location of the jet shell associated with the first pulse in the second emission episode of GRB 160625B. It is found that the radiation location increases with time. In addition, the Lorentz factor remains almost constant during the expansion of the jet shell. This reveals that the magnetization of the jet is low or intermediate in the emission region, even though the jet could still be Poynting-flux-dominated at smaller radii to avoid a bright thermal component in the emission episode.
Ion and Electron Dynamics in the Presence of Mirror, Electromagnetic Ion Cyclotron, and Whistler Waves
Authors: Zhao Jinsong , Wang Tieyan , Shi Chen , Graham Daniel B. , Dunlop Malcolm W. , He Jiansen , Tsurutani Bruce T. , Wu Dejin 
Published: October 2019

Abstract
The wave–particle cyclotron interaction is a basic process in collisionless plasmas, which results in the redistribution of the energy between plasma waves and charged particles. This paper presents an event observation in order to explore the dynamics of charged particles and plasma waves, i.e., mirror, electromagnetic ion cyclotron (EMIC), and whistler waves, in the Earth’s magnetosheath. It shows that when ions have a high-speed streaming velocity parallel to the magnetic field, EMIC waves arise. We also find that the frequency distribution of nearly parallel and nearly antiparallel whistler waves depends on the parallel streaming velocity of electrons. Based on the linear kinetic theory and the fitting plasma parameters, we show that the differential flows among ion components can enhance the ion cyclotron anisotropy instability that is even stronger than the mirror instability. The differential electron flows induce an asymmetry of the growth rate of counter-propagating whistler waves in the electron cyclotron anisotropy instability. On the other hand, the low-frequency EMIC and transverse electromagnetic waves modulate the ion pitch angle distribution. Moreover, when charged particles flow across the magnetic field, both low- and high-energy electrons are deeply trapped by mirror waves. These results illustrate new features of the observed plasma waves and charged particles in the Earth’s magnetosheath, which could inspire improvement of the wave models therein.
On the Role of a Cavity in the Hypernova Ejecta of GRB 190114C
Authors: Ruffini R. , Fuksman J. D. Melon , Vereshchagin G. V. 
Published: October 2019

Abstract
Within the binary-driven hypernova I (BdHN I) scenario, the gamma-ray burst GRB190114C originates in a binary system composed of a massive carbon–oxygen core (COcore), and a binary neutron star (NS) companion. As the COcore undergoes a supernova explosion with the creation of a new neutron star (νNS), hypercritical accretion occurs on the companion binary neutron star until it exceeds the critical mass for gravitational collapse. The formation of a black hole (BH) captures 1057 baryons by enclosing them within its horizon, and thus a cavity of approximately 1011 cm is formed around it with initial density 10−7 g cm−3. A further depletion of baryons in the cavity originates from the expansion of the electron-positron-photon (e
+
e
−
γ) plasma formed at the collapse, reaching a density of 10−14 g cm−3 by the end of the interaction. It is demonstrated here using an analytical model complemented by a hydrodynamical numerical simulation that part of the e
+
e
−
γ plasma is reflected off the walls of the cavity. The consequent outflow and its observed properties are shown to coincide with the featureless emission occurring in a time interval of duration t
rf, measured in the rest frame of the source, between 11 and 20 s of the GBM observation. Moreover, similar features of the GRB light curve were previously observed in GRB 090926A and GRB 130427A, all belonging to the BdHN I class. This interpretation supports the general conceptual framework presented in R. Ruffini et al. and guarantees that a low baryon density is reached in the cavity, a necessary condition for the operation of the “inner engine” of the GRB presented in an accompanying article.
Tidal-locking-induced Stellar Rotation Dichotomy in the Open Cluster NGC 2287?
Authors: Sun Weijia , Li Chengyuan , Deng Licai , de Grijs Richard 
Published: October 2019

Abstract
Stars spend most of their lifetimes on the “main sequence” (MS) in the Hertzsprung–Russell diagram. The obvious double MSs seen in the equivalent color–magnitude diagrams characteristic of Milky Way open clusters (OCs) pose a fundamental challenge to our traditional understanding of star clusters as “single stellar populations.” The clear MS bifurcation of early-type stars with masses greater than ∼1.6 M
⊙ is thought to result from a range in the stellar rotation rates. However, direct evidence connecting double MSs to stellar rotation properties has yet to emerge. Here, we show through analysis of the projected stellar rotational velocities (v sin i, where i represents the star’s inclination angle) that the well-separated double MS in the young, ∼200 Myr old Milky Way OC NGC 2287 is tightly correlated with a dichotomous distribution of stellar rotation rates. We discuss whether our observations may reflect the effects of tidal locking affecting a fraction of the cluster’s member stars in stellar binary systems. We show that the slow rotators could potentially be initially rapidly rotating stars that have been slowed down by tidal locking by a low-mass-ratio companion in a cluster containing a large fraction of short-period, low-mass-ratio binaries. This demonstrates that stellar rotation drives the split MSs in young, ⪅300 Myr old star clusters. However, special conditions, e.g., as regards the mass-ratio distribution, might be required for this scenario to hold.
Cloud Atlas: Variability in and out of the Water Band in the Planetary-mass HD 203030B Points to Cloud Sedimentation in Low-gravity L Dwarfs
Authors: Miles-Páez Paulo A. , Metchev Stanimir , Apai Dániel , Zhou Yifan , Manjavacas Elena , Karalidi Theodora , Lew Ben W. P. , Burgasser Adam J. , Bedin Luigi R. , Cowan Nicolas , Lowrance Patrick J. , Marley Mark S. , Radigan Jacqueline , Schneider Glenn 
Published: October 2019

Abstract
We use the Wide Field Camera 3 on the Hubble Space Telescope to spectrophotometrically monitor the young L7.5 companion HD 203030B. Our time series reveal photometric variability at 1.27 and 1.39 μm on timescales compatible with rotation. We find a rotation period of

hr: comparable to those observed in other brown dwarfs and planetary-mass companions younger than 300 Myr. We measure variability amplitudes of 1.1% ± 0.3% (1.27 μm) and 1.7% ± 0.4% (1.39 μm), and a phase lag of 56° ± 28° between the two light curves. We attribute the difference in photometric amplitudes and phases to a patchy cloud layer that is sinking below the level where water vapor becomes opaque. HD 203030B and the few other known variable young late-L dwarfs are unlike warmer (earlier-type and/or older) L dwarfs, for which variability is much less wavelength-dependent across the 1.1–1.7 μm region. We further suggest that a sinking of the top-most cloud deck below the level where water or carbon monoxide gas become opaque may also explain the often enhanced variability amplitudes of even earlier-type low-gravity L dwarfs. Because these condensate and gas opacity levels are already well-differentiated in T dwarfs, we do not expect the same variability amplitude enhancement in young versus old T dwarfs.
First Subarcsecond Submillimeter-wave [C i] Image of 49 Ceti with ALMA
Authors: Higuchi Aya E. , Saigo Kazuya , Kobayashi Hiroshi , Iwasaki Kazunari , Momose Munetake , Lou Soon Kang , Sakai Nami , Kunitomo Masanobu , Ishihara Daisuke , Yamamoto Satoshi 
Published: October 2019

Abstract
We present the first subarcsecond images of 49 Ceti in the [C i] 3
P
1–3
P
0 emission and the 614 μm dust continuum emission observed with Atacama Large Millimeter/submillimeter Array (ALMA), as well as that in the CO(J = 3–2) emission prepared by using the ALMA archival data. The spatial distribution of the 614 μm dust continuum emission is found to have a broad-ring structure with a radius of about 100 au around the central star. A substantial amount of gas is also associated with 49 Ceti. The [C i] emission map shows two peaks inside the dust ring, and its overall extent is comparable to that of the dust continuum emission and the CO emission. We find that the [C i]/CO(J = 3–2) intensity ratio significantly varies along the major axis. The ratio takes the minimum value of 1.8 around the dust peak position, and increases inward and outward. The enhanced ratio around the central star (∼3) likely originates from the stellar UV radiation, while that in the outer disk (∼10) is from the interstellar UV radiation. Such complex distributions of the [C i] and CO(J = 3–2) emission will be key to understanding the origin of the gas in 49 Ceti, and will also provide a stringent constraint on physical and chemical models of gaseous debris disks.
Turbulence versus Fire-hose Instabilities: 3D Hybrid Expanding Box Simulations
Authors: Hellinger Petr , Matteini Lorenzo , Landi Simone , Franci Luca , Verdini Andrea , Papini Emanuele 
Published: October 2019

Abstract
The relationship between a decaying plasma turbulence and proton fire hose instabilities in a slowly expanding plasma is investigated using three-dimensional hybrid expanding box simulations. We impose an initial ambient magnetic field along the radial direction, and we start with an isotropic spectrum of large-scale, linearly polarized, random-phase Alfvénic fluctuations with zero cross-helicity. A turbulent cascade rapidly develops and leads to a weak proton heating that is not sufficient to overcome the expansion-driven perpendicular cooling. The plasma system eventually drives the parallel and oblique fire hose instabilities that generate quasi-monochromatic wave packets that reduce the proton temperature anisotropy. The fire hose wave activity has a low amplitude with wave vectors quasi-parallel/oblique with respect to the ambient magnetic field outside of the region dominated by the turbulent cascade and is discernible in one-dimensional power spectra taken only in the direction quasi-parallel/oblique with respect to the ambient magnetic field; at quasi-perpendicular angles the wave activity is hidden by the turbulent background. These waves are partly reabsorbed by protons and partly couple to and participate in the turbulent cascade. Their presence reduces kurtosis, a measure of intermittency, and the Shannon entropy, but increases the Jensen–Shannon complexity of magnetic fluctuations; these changes are weak and anisotropic with respect to the ambient magnetic field and it is not clear if they can be used to indirectly discern the presence of instability-driven waves.
In the Galactic Disk, Stellar [Fe/H] and Age Predict Orbits and Precise [X/Fe]
Authors: Ness M. K. , Johnston K. V. , Blancato K. , Rix H-W. , Beane A. , Bird J. C , Hawkins K. 
Published: October 2019

Abstract
We explore the structure of the element abundance–age–orbit distribution of the stars in the Milky Way’s low-α disk, by (re-)deriving precise [Fe/H], [X/Fe], and ages, along with orbits, for red clump stars from the apogee survey. There has been a long-standing theoretical expectation and observational evidence that metallicity ([Fe/H]) and age are informative about a star’s orbit, e.g., about its angular momentum and the corresponding mean Galactocentric distance or its vertical motion. Indeed, our analysis of the apogee data confirms that [Fe/H] or age alone can predict the stars’ orbits far less well than a combination of the two. Remarkably, we find and show explicitly that, for known [Fe/H] and age, the other abundances [X/Fe] of Galactic disk stars can be predicted well (on average to 0.02 dex) across a wide range of Galactocentric radii, and therefore provide little additional information, e.g., for predicting their orbit. While the age–abundance space for metal-poor stars and potentially for stars near the Galactic center is rich or complex, for the bulk of the Galaxy’s low-α disk it is simple: [Fe/H] and age contain most information, unless [X/Fe] can be measured to 0.02 or better. Consequently, we do not have the precision with current (and likely near-future) data to assign stars to their individual (coeval) birth clusters, from which the disk is presumably formed. We can, however, place strong constraints on future models of Galactic evolution, chemical enrichment, and mixing.
Bayesian Inference of High-density Nuclear Symmetry Energy from Radii of Canonical Neutron Stars
Authors: Xie Wen-Jie , Li Bao-An 
Published: October 2019

Abstract
The radius R
1.4 of neutron stars (NSs) with a mass of 1.4 M
⊙ has been extracted consistently in many recent studies in the literature. Using representative R
1.4 data, we infer high-density nuclear symmetry energy E
sym(ρ) and the associated nucleon specific energy E
0(ρ) in symmetric nuclear matter (SNM) within a Bayesian statistical approach using an explicitly isospin-dependent parametric equation of state (EOS) for nucleonic matter. We found the following. (1) The available astrophysical data can already significantly improve our current knowledge about the EOS in the density range of ρ
0 − 2.5ρ
0. In particular, the symmetry energy at twice the saturation density ρ
0 of nuclear matter is determined to be E
sym(2ρ
0)=

MeV at a 68% confidence level. (2) A precise measurement of R
1.4 alone with a 4% 1σ statistical error but no systematic error will not greatly improve the constraints on the EOS of dense neutron-rich nucleonic matter compared to what we extracted from using the available radius data. (3) The R
1.4 radius data and other general conditions, such as the observed NS maximum mass and causality condition, introduce strong correlations for the high-order EOS parameters. Consequently, the high-density behavior of E
sym(ρ) inferred depends strongly on how the high-density SNM EOS E
0(ρ) is parameterized, and vice versa. (4) The value of the observed maximum NS mass and whether it is used as a sharp cutoff for the minimum maximum mass or through a Gaussian distribution significantly affects the lower boundaries of both E
0(ρ) and E
sym(ρ) only at densities higher than about 2.5ρ
0.
Discovery of Metastable He I* λ10830 Mini-broad Absorption Lines and Very Narrow Paschen α Emission Lines in the ULIRG Quasar IRAS F11119+3257
Authors: Pan Xiang , Zhou Hongyan , Liu Wenjuan , Liu Bo , Ji Tuo , Shi Xiheng , Zhang Shaohua , Jiang Peng , Wang Huiyuan , Hao Lei 
Published: October 2019

Abstract
IRAS F11119+3257 is a quasar-dominated ultraluminous infrared galaxy, with a partially obscured narrow-line Seyfert 1 nucleus. In this paper, we present the near-IR (NIR) spectroscopy of F11119+3257, in which we find unusual Paschen emission lines and metastable He i* λ10830 absorption associated with the previously reported atomic sodium and molecular OH mini-BAL (broad absorption line) outflow. Photoionization diagnosis confirms previous findings that the outflows are at kiloparsec scales. Such large-scale outflows should produce emission lines. We indeed find that high-ionization emission lines ([O III], [Ne III], and [Ne V]) are dominated by blueshifted components at similar speeds to the mini-BALs. The blueshifted components are also detected in some low-ionization emission lines, such as [O II] λ3727 and some Balmer lines (Hα, Hβ, and Hγ), even though their cores are dominated by narrow (FWHMNEL = 570 ± 40 km s−1) or broad components at the systemic redshift of z = 0.18966 ± 0.00006. The mass flow rate (230–730 M
⊙ yr−1) and the kinetic luminosity (

erg s−1) are then inferred jointly from the blueshifted emission and absorption lines. In the NIR spectrum of F11119+3257, we also find that the Paschen emission lines are unique, in which a very narrow (FWHM = 260 ± 20 km s−1) component is shown in only Paα. This narrow component most probably comes from heavily obscured star formation. Based on the Paα and Paβ emissions, we obtain an extinction at the H band, A

H
> 2.1 (or a reddenning of

> 3.7), and a star formation rate of SFR > 130 M
⊙ yr−1 that resembles the estimates inferred from the far-IR emissions (SFRFIR = 190 ± 90 M
⊙ yr−1).
Geographic review on the specimens of the Caatinga Biome in the Jardim Botânico do Rio de Janeiro (RB) herbarium
Authors: Magdalena Ulises , Silva Luís Alexandre , Oliveira Felipe , Lima Rafael , Bellon Ernani , Ribeiro Rafael , Lanna João , Abieri Maria Luiza , Cardoso Gabriel , Amorim Aline , Forzza Rafaela 
Published: October 2019

This article provides a quantitative description of flora specimens stored in the Jardim Botânico of Rio de Janeiro Herbarium that belongs to the Federal Conservation Units of Caatinga’s phytogeography domain. The Caatinga represents 11% of Brazilian territory and is, in South America, the largest and most biodiverse semi-arid tropical ecoregion, yet only 5% of its territory is covered by Federal Conservation Units, with few collections of flora samples. Thus, providing a georeferenced inventory of existing collections is essential for purposes of species distribution, environmental management and conservation. The aim of this data paper is to gauge, by means of geographic coordinates correction and retrieval of the flora specimens present in the RB Herbarium, the amount of specimen gatherings performed in the Federal Conservation Units belonging to the Caatinga domain.Currently, the RB data is publicly available online at several biodiversity portals, such as our institutional database JABOT, the Reflora Virtual Herbarium, the SiBBr and the GBIF portal (Lanna et al. 2019). However, a description of the dataset that belongs to the Federal Conservation Units of Caatinga’s phytogeography domain as a whole is not yet available in the literature.
IA et emploi : une menace artificielle
Authors: Askenazy Philippe , Bach Francis 
Published: October 2019

Les récents succès de l’ ia ont nourri un discours, souvent anxiogène, d’une obsolescence du travail humain. Si des acteurs divers ont intérêt à diffuser ce message, notre analyse d’informaticien et d’économiste, nécessairement spéculative, souligne les limites technologiques et sociales de l’intelligence artificielle. Nous renversons ainsi la problématique : l’ ia couplée aux robots sera-t-elle suffisante pour permettre aux sociétés occidentales fermées à l’immigration de répondre aux défis du xxi e siècle qui exigeront beaucoup de travail ?
Éthique et conscience des robots
Authors: Ndior Valère 
Published: October 2019

Alors que se multiplient les travaux scientifiques consacrés au « droit des robots » émerge une interrogation persistante, alimentée par les expériences récentes des roboticiens : les robots peuvent-ils devenir trop conscients d’eux-mêmes, au point de nuire à la société et de rendre le droit commun obsolète ? Envisager les risques éthiques et juridiques associés au développement d’une « conscience » du robot suppose de déterminer la capacité de ses concepteurs à développer l’intelligence artificielle au-delà du seuil de « Singularité technologique ».
IA et éducation
Authors: Alexandre Laurent 
Published: October 2019

L’école, en tant que technologie de transmission de l’intelligence, est d’ores et déjà une technologie dépassée. Sa modernisation accélérée sous l’effet des technologies numériques constituera en réalité les derniers feux d’une institution vouée à prendre place dans l’histoire au rayon des curiosités du passé, fondées sur une science approximative, au même titre que les sanatoriums. À partir de 2035, l’éducation deviendra une « branche de la médecine », utilisant les immenses ressources des neurosciences pour personnaliser d’abord la transmission et optimiser ensuite bioélectroniquement l’intelligence. Ce sera la seule solution pour éviter un apartheid intellectuel dans un monde rendu ultra-compétitif par l’ ia .
Evaluation of an Australian Health Literacy Program Delivered in Adult Education Settings
Authors: McCaffery Kirsten J. , Morony Suzanne , Muscat Danielle M. , Hayen Andrew , Shepherd Heather L. , Dhillon Haryana M. , Smith Sian K. , Cvejic Erin , Meshreky Wedyan , Luxford Karen , Nutbeam Don 
Published: October 2019

Background:
Adult education targeting health literacy (HL) may bring added value in the form of improved health.

Objective:
This study evaluated the effects of a HL program as part of an adult education curriculum for adults with low literacy and numeracy.

Methods:

This was a partial-cluster randomized controlled trial among 308 adults enrolled in basic education programs in Australia. Of the 308 participants, 141 (46%) were randomized to either the standard program (language, literacy, and numeracy [LLN]), or the HL intervention (LLN with embedded health content); the remainder (
n
= 167) were allocated to standard intervention programs by the education provider at the class level. The main outcomes were functional HL, self-reported confidence, patient activation, generic HL (ie, HLQ, health knowledge, and self-reported health behavior). Data were collected at baseline, immediately after, and at 6 months post-intervention.

Key Results:

Of the 308 participants, 71% had limited literacy and 60% spoke a language other than English at home. Both interventions benefited participants, with improvements from baseline to immediate follow up on individual-level functional HL (e.g., reading a thermometer; HL group 18.4% vs. standard group 7.2%;
p
= .001), confidence (HL group 0.34 vs. standard group 0.06;
p
= .014) and health literacy questionnaire (HLQ) subscales. At 6 months, improvements in confidence (
p
< .001) and some HLQ measures were retained. A consistent pattern of increased improvement in the HL program was observed compared to the standard program, although only some measures reached statistical significance: reading a food label (HL group 6.03/10 correct vs. standard group 5.49/10 correct;
p
= .022); confidence (
p
= .008); ability to actively manage health (HLQ) (
p
= .017), and health knowledge at 6 months (HL group 68% vs. standard group 60% correct,
p
= .052). HL participants reported being more likely to share course information and rated the program more useful to understand their health.

Conclusions:

Improving language, literacy, and numeracy generally has potential public health benefits that are retained at 6 months. Integrating health content adds further value to adult basic learning, is feasible, and potentially scalable.

[
HLRP: Health Literacy Research and Practice
. 2019;3(Suppl.):S42–S57.]

Plain Language Summary:
We compared the effect of an adult education-based health literacy (HL) program versus a standard language, literacy, and numeracy program on students' HL skills and psychosocial outcomes. Although students in both trial arms improved their skills, students in the HL program had better outcomes with higher HL, greater confidence, and higher health knowledge scores at 6 months.