bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Short GRB 170817A: Modeling the Off-axis Emission and Implications on the Ejecta Magnetization
Authors: Fraija N. , Colle F. De , Veres P. , Dichiara S. , Duran R. Barniol , Galvan-Gamez A. , do E. S. Pedreira A. C. Caligula 
Published: January 2019

Abstract
The short GRB 170817A, detected by the Fermi Gamma-ray Burst Monitor, orbiting satellites and ground-based telescopes, was the electromagnetic counterpart of a gravitational-wave transient (GW170817) from a binary neutron star merger. After this merger, the γ-ray light curve exhibited a faint peak at ∼1.7 s and the X-ray, optical, and radio light curves displayed extended emission that increased in brightness up to ∼160 days. In this paper, we show that the X-ray, optical and radio fluxes are consistent with the synchrotron forward-shock model viewed off-axis when the matter in the outflow is parameterized through a power-law velocity distribution. We discuss the origin of the γ-ray peak in terms of internal and external shocks. We show that the γ-ray flux might be consistent with a synchrotron self-Compton reverse-shock model observed at high latitudes. Comparing the best-fit values obtained after describing the γ-ray, X-ray, optical, and radio fluxes with our model, we find that the afterglow and γ-ray emission occurred in different regions and also find evidence to propose that the progenitor environment was entrained with magnetic fields; therefore we argue for the presence of magnetic field amplification in the binary neutron star merger.
Does High-density or Mass Help Star Clusters Produce X-Ray Binaries in Star-forming Galaxies?
Authors: Johns Mulia P. , Chandar R. , Rangelov B. 
Published: January 2019

Abstract
It is now widely accepted that many X-ray binaries (XRBs) form in compact star clusters. Therefore, it follows that there may be a link between the properties of star clusters and the production of XRBs. We study the masses and densities of compact clusters with different ages found in the merging Antennae galaxies and in the dwarf starburst NGC 4449, to assess their impact on the production of XRBs. The very youngest clusters, with ages log (τ/yr) < 7.0, likely host high-mass XRBs, while older clusters with ages log (τ/yr) = 7.0–8.6 host intermediate-mass XRBs. We find tentative evidence that intermediate-mass XRBs are more likely to form in more massive and dense clusters, while high-mass XRBs do not appear to form in clusters that favor higher masses or densities. If confirmed, these findings support a picture where high-mass and intermediate-mass XRBs form through different mechanisms.
The Circular Velocity Curve of the Milky Way from 5 to 25 kpc
Authors: Eilers Anna-Christina , Hogg David W. , Rix Hans-Walter , Ness Melissa K. 
Published: January 2019

Abstract
We measure the circular velocity curve v
c(R) of the Milky Way with the highest precision to date across Galactocentric distances of 5 ≤ R ≤ 25 kpc. Our analysis draws on the six-dimensional phase-space coordinates of ≳23,000 luminous red giant stars, for which we previously determined precise parallaxes using a data-driven model that combines spectral data from APOGEE with photometric information from WISE, 2MASS, and Gaia. We derive the circular velocity curve with the Jeans equation assuming an axisymmetric gravitational potential. At the location of the Sun we determine the circular velocity with its formal uncertainty to be

=

with systematic uncertainties at the ∼2%–5% level. We find that the velocity curve is gently but significantly declining at (−1.7 ± 0.1) km s−1 kpc−1, with a systematic uncertainty of 0.46 km s−1 kpc−1, beyond the inner 5 kpc. We exclude the inner 5 kpc from our analysis due to the presence of the Galactic bar, which strongly influences the kinematic structure and requires modeling in a nonaxisymmetric potential. Combining our results with external measurements of the mass distribution for the baryonic components of the Milky Way from other studies, we estimate the Galaxy’s dark halo mass within the virial radius to be

=

and a local dark matter density of

=

.
A Comparison between Radio Loud and Quiet Gamma-Ray Bursts, and Evidence for a Potential Correlation between Intrinsic Duration and Redshift in the Radio Loud Population
Authors: Lloyd-Ronning Nicole M. , Gompertz Ben , Pe’er Asaf , Dainotti Maria , Fruchter Andy 
Published: January 2019

Abstract
We extend our study of energetic radio-loud and -quiet gamma-ray bursts (GRBs), suggesting these GRBs potentially come from two separate progenitor systems. We expand the sample from our previous paper and find that our results are strengthened—radio-quiet GRBs have significantly shorter intrinsic prompt duration, and are also less energetic on average. However, the tenuous correlation between isotropic energy and intrinsic duration in the radio dark sample remains tenuous and is slightly weakened by adding more bursts. Interestingly, we find an anticorrelation between the intrinsic duration and redshift in the radio bright sample but not the radio dark sample, further supporting that these two samples may come from separate progenitors. We also find that very high energy (0.1–100 GeV) extended emission is only present in the radio-loud sample. There is no significant difference between the presence of X-ray/optical plateaus or the average jet opening angles between the two samples. We explore the interpretation of these results in the context of different progenitor models. The data are consistent with the radio-loud GRBs coming from a helium merger system and the radio-quiet GRBs coming from a collapsar system, but may also reflect other dichotomies in the inner engine such as a neutron star versus black hole core.
Black Hole Hyperaccretion Inflow–Outflow Model. II. Long-duration Gamma-Ray Bursts and Supernova 56Ni Bumps
Authors: Song Cui-Ying , Liu Tong 
Published: January 2019

Abstract
Long-duration gamma-ray bursts (LGRBs) associated with supernovae (SNe) are possibly born out of the death of a massive star. After the star collapses, a stellar-mass black hole (BH) is formed, surrounded by a hyperaccretion disk with outflows. Blandford–Znajek jets can be launched and then break out from the envelope to power LGRBs. The jet luminosity depends on the net inflow accretion rate at the inner radius of the disk. Furthermore, 56Ni synthesis should occur in the strong outflows from the accretion disk. The decay of 56Ni is considered to be the possible origin of SN bumps in the subsequent optical afterglows of LGRBs. If 56Ni originates entirely from the outflows, there is competition between the luminosities of LGRBs and those of the corresponding 56Ni bumps because of the material distribution between the disk inflows and outflows. In this paper, we investigated these two luminosities based on 15 cases of LGRB–SN in the framework of the BH hyperaccretion inflow–outflow model. Then, one can constrain the characteristics of the progenitor stars of these LGRBs. The results indicate that these LGRBs may originate from the low-metallicity (

, where Z and Z
⊙ are the metallicities of the stars and the Sun, respectively) stars or some massive solar-metallicity stars. For ultra-LGRBs (ULGRBs), such as GRB 111209A, most of the massive low-metallicity stars with

could be progenitors only if very strong outflows are launched from the disks. When the contributions of nucleosynthesis in the disk outflows are considered, there is no shortage of 56Ni mass for luminous SNe associated with ULGRBs.
Evidence for Optically Thick, Eddington-limited Winds Driven by Supercritical Accretion
Authors: Zhou Yu , Feng Hua , Ho Luis C. , Yao Yuhan 
Published: January 2019

Abstract
Supercritical accretion onto compact objects powers a massive wind that is optically thick and Eddington-limited. If most of the hard X-rays from the central disk are obscured by the wind, the source will display a blackbody-like spectrum with a luminosity scaled with the mass of the compact object. From the Chandra archive of nearby galaxies, we selected a sample of luminous and very soft sources and excluded contamination from foreground objects and supernova remnants. They are found to be preferentially associated with late-type galaxies. The majority of sources in our sample are either too hot or too luminous to be explained by nuclear burning on the surface of white dwarfs, and are argued to be powered by accretion. The most likely explanation is that they are due to emission from the photosphere of a wind driven by supercritical accretion onto compact objects. Their blackbody luminosity ranges from ∼1037 to nearly 1040 erg s−1, indicative of the presence of both neutron stars and stellar-mass black holes. The blackbody luminosity also shows a possible bimodal distribution, albeit at low significance, peaked around the Eddington limit for neutron stars and stellar-mass black holes, respectively. If this can be confirmed, it will be smoking gun evidence that supercritical accretion powers thick winds. Based on a wind model, the inferred mass accretion rate of these objects is around a few hundred times the Eddington rate, suggesting that they may be intermediate between the canonical ultraluminous X-ray sources and SS 433 in terms of the accretion rate.
Hubble Constant from LSST Strong-lens Time Delays with Microlensing Systematics
Authors: Liao Kai 
Published: January 2019

Abstract
Strong-lens time delays have been widely used in cosmological studies, especially to infer H
0. The upcoming LSST will provide several hundred well-measured time delays from the light curves of lensed quasars. However, due to the inclination of the finite AGN accretion disk and the differential magnification of the coherent temperature fluctuations, the microlensing by the stars can lead to changes in the actual time delay on the light-crossing timescale of the emission region of ∼days. We first study how this would change the uncertainty of H
0 in the LSST era, assuming the microlensing time delays can be well estimated. We adopt 1/3, 1, and 3 days respectively as the typical microlensing time-delay uncertainties. The relative uncertainty of H
0 will be enlarged to 0.47%, 0.51%, and 0.76%, from the uncertainty without the microlensing, impact 0.45%. Then, due to our lack of understanding of the quasar models and microlensing patterns, we also test the reliability of the results if one neglects this effect in the analysis. The biases of H
0 will be 0.12%, 0.22% and 0.70%, suggesting that 1 day is the cutoff for a robust H
0 estimate.
Gas Density Perturbations Induced by One or More Forming Planets in the AS 209 Protoplanetary Disk as Seen with ALMA
Authors: Favre Cécile , Fedele Davide , Maud Luke , Booth Richard , Tazzari Marco , Miotello Anna , Testi Leonardo , Semenov Dmitry , Bruderer Simon 
Published: January 2019

Abstract
The formation of planets occurs within protoplanetary disks surrounding young stars, resulting in perturbation of the gas and dust surface densities. Here we report the first evidence of spatially resolved gas surface density (Σ
g
) perturbation toward the AS 209 protoplanetary disk from the optically thin C18O (J = 2−1) emission. The observations were carried out at 1.3 mm with Atacama Large Millimeter/submillimeter Array at a spatial resolution of about 0.″3 × 0.″2 (corresponding to ∼38 × 25 au). The C18O emission shows a compact (≤60 au), centrally peaked emission and an outer ring peaking at 140 au, consistent with that observed in the continuum emission, and its azimuthally averaged radial intensity profile presents a deficit that is spatially coincident with the previously reported dust map. This deficit can only be reproduced with our physico-thermochemical disk model by lowering Σgas by nearly an order of magnitude in the dust gaps. Another salient result is that, contrary to C18O, the DCO+ (J = 3−2) emission peaks between the two dust gaps. We infer that the best scenario to explain our observations (C18O deficit and DCO+ enhancement) is a gas perturbation due to one or more forming planets, which is commensurate with previous continuum observations of the source along with hydrodynamical simulations. Our findings confirm that the previously observed dust gaps are very likely due to perturbation of the gas surface density that is induced by a planet of at least 0.2M
J in formation. Finally, our observations also show the potential of using CO isotopologues to probe the presence of one or more Saturn-mass planets.
The Galactic Magneto-ionic Medium Survey: Moments of the Faraday Spectra
Authors: Dickey John M. , Landecker T. L. , Thomson Alec J. M. , Wolleben M. , Sun X. , Carretti E. , Douglas K. , Fletcher A. , Gaensler B. M. , Gray A. , Haverkorn M. , Hill A. S. , Mao S. A. , McClure-Griffiths N. M. 
Published: January 2019

Abstract
Faraday rotation occurs along every line of sight in the Galaxy; rotation measure (RM) synthesis allows a 3D representation of the interstellar magnetic field. This study uses data from the Global Magneto-Ionic Medium Survey, a combination of single-antenna spectro-polarimetric studies, including northern sky data from the Dominion Radio Astrophysical Observatory (DRAO) 26 m telescope (1270–1750 MHz) and southern sky data from the Parkes 64 m telescope (300–480 MHz). From the synthesized Faraday spectral cubes we compute the zeroth, first, and second moments to find the total polarized emission, mean RM, and RM width of the polarized emission. From DRAO first moments we find a weak vertical field directed from Galactic North to South, but Parkes data reveal fields directed toward the Sun at high latitudes in both hemispheres: the two surveys clearly sample different volumes. DRAO second moments show feature widths in Faraday spectra increasing with decreasing positive latitudes, implying that longer lines of sight encounter more Faraday rotating medium, but this is not seen at negative latitudes. Parkes data show the opposite: at positive latitudes the second moment decreases with decreasing latitude, but not at negative latitudes. Comparing first moments with RMs of pulsars and extragalactic sources and a study of depolarization together confirm that the DRAO survey samples to larger distances than the Parkes data. Emission regions in the DRAO survey are typically 700–1000 pc away, slightly beyond the scale height of the magneto-ionic medium; emission detected in the Parkes survey is entirely within the magneto-ionic disk, less than 500 pc away.
Characteristics of Plasma Cavities That Appeared in the Intensity Dropout Event of Solar Energetic Particles
Authors: Tan Lun C. 
Published: January 2019

Abstract
In order to explore the origin of the particle “dropout” phenomenon in the “gradual” solar energetic particle (SEP) event, we have selected 13 dropout intervals from 10 gradual SEP events during solar cycle 23. Our selection criterion is that within the dropout interval the average slab turbulence fraction is >0.8 in the ion dissipation range. In the plasma “cavity” that appeared in the dropout interval we have observed the angles of the wavenumber vector and the solar wind velocity vector relative to the mean magnetic field direction to be ∼0° and ∼90°, respectively. The distinctive feature of the cavity geometry could inhibit the occurrence of kinetic Alfvén waves (KAWs), leaving the dominance of magnetosonic-whistler waves in its plasma environment. Therefore, by examining the difference of turbulence characteristics between the dropout interval and the ambient solar wind, we are able to differentiate between the effects of KAWs and quasi-parallel whistler waves. Observations of the plasma β dependence of magnetic power density spectra in the ion dissipation range indicate that in the cavity of low plasma β (≤1) and low magnetic variance anisotropy (∼3) the turbulence cascade of the magnetosonic-whistler wave branch has reached a sufficiently developed stage.
L’Information jeunesse : une socialisation citoyenne pour tous les jeunes ?
Authors: Danic Isabelle 
Published: January 2019

L’étude d’un centre régional d’information jeunesse visant à « promouvoir [la] participation [des jeunes] comme membres actifs dans la société » révèle la mise en œuvre concomitante de plusieurs dispositifs de participation qui peuvent être envisagés comme formation à différents registres de citoyenneté. En venant s’informer, en étant accompagnés dans leurs projets et en participant aux actions proposées, de nombreux jeunes développent une citoyenneté juridique et civile. À côté de ces opportunités explicitement proposées à tous, l’institution repère et incite les jeunes qui leur semblent aptes à s’investir dans sa gouvernance. Cette socialisation à la citoyenneté politique est ainsi structurée socialement : les jeunes qui s’impliquent ont un niveau d’instruction et souvent une première expérience citoyenne qui leur permet d’intégrer la fonction d’administrateur.
Pars Plana Lensectomy for the Management of Ectopia Lentis in Children
Authors: Shortt Alex J. , Lanigan Bernie , O’Keefe Michael 
Published: January 2019

Background:
Nontraumatic ectopia lentis arises from a variety of inherited disorders. It may also occur as an isolated abnormality in an otherwise healthy individual. Surgical intervention is necessary when lens subluxation causes a significant refractive error resulting in amblyopia.

Patients and Methods:
We report the results of pars plana lensectomy for nontraumatic ectopia lentis in 24 eyes of 13 patients and provide data on the merits of this surgical approach.

Results:
Postoperative visual acuity was 6/9 or better in 17 of 22 eyes and 6/12 or better in 19 of 22 eyes. Other than contact lens–related problems, there were no perioperative or postoperative complications.

Conclusions:
Pars plana lensectomy is a safe, effective procedure for the management of ectopia lentis. Visual outcomes are excellent. These findings should encourage earlier surgery when indicated to prevent amblyopia and improve visual acuity.

J Pediatr Ophthalmol Strabismus
2004;41:289–294.
Surgical Treatment of Advanced Chronic Angle Closure Glaucoma in Weill–Marchesani Syndrome
Authors: Harasymowycz Paul , Wilson Richard 
Published: January 2019

Purpose:
To describe the surgical treatment of advanced chronic angle closure glaucoma in Weill–Marchesani syndrome.

Patients and Methods:
Two children with Weill–Marchesani syndrome (4 eyes) undergoing lensectomy, anterior vitrectomy, and sutured intraocular lens (IOL) and Molteno tube shunt surgery at Wills Eye Hospital were prospectively studied. Visual acuity and intraocular pressure (IOP) were recorded.

Results:
Both patients presented with increasing myopia and advanced glaucomatous damage. Laser iridotomy was ineffective in deepening the anterior chamber. The first patient developed a flat anterior chamber after trabeculectomy. At the 12-month follow-up visit, all 4 eyes had an important decrease in IOP and cupping after combined lensectomy, anterior vitrectomy, and sutured IOL and Molteno tube shunt placement. One eye had a transitory postoperative choroidal effusion and retinal detachment that resolved spontaneously.

Conclusions:
Advanced chronic angle closure glaucoma in Weill–Marchesani syndrome may be treated with a combination of lensectomy, anterior vitrectomy, and sutured IOL and Molteno tube shunt surgery. In early cases, prophylactic peripheral iridotomies should be stressed.

J Pediatr Ophthalmol Strabismus
2004;41:295–299.
Comparison of Ultrasonic and Ophthalmoscopic Evaluation of Retinopathy of Prematurity
Authors: Jokl Danny H.-Kauffmann , Silverman Ronald H. , Springer Alan D. , Towers Helen , Kane Steven , Lopez Robert , Chiang Michael F. , Lloyd Harriet O. , Barbazetto Irene , Horowitz Robyn , Vidne Orit 
Published: January 2019

Purpose:
Screening for detection of retinopathy of prematurity (ROP) currently is limited to indirect ophthalmoscopy, which requires considerable examiner skill and experience. We investigated whether conventional 10 MHz B-scan ultrasonography could document the clinical stages of ROP as accurately as indirect ophthalmoscopy.

Methods:
Thirty-four eyes of 18 neonates were examined by masked, independent observers with indirect ophthalmoscopy and digitally recorded 10-MHz B-scan ultrasonography. After pupil dilation and lid speculum placement, the retinologist recorded the stage of retinopathy with a retinal drawing. The ultrasonographer, without use of papillary mydriatics or lid speculum, determined the presence or absence of a ridge or tractional elements, if present on the ridge.

Results:

Ultrasound grade correlated with clinical grade (
R
= .79,
P
< .001). However, nine eyes were overdiagnosed by one stage, and one eye, in which a peripheral detachment was mistaken for an artifact, was underdiagnosed.

Conclusions:
Ten-megahertz ultrasonography offers the potential of imaging and detecting the clinical stages of ROP; the use of higher ultrasound frequencies, now becoming commercially available, is likely to enhance diagnostic accuracy. Care must be taken to distinguish between artifact and true anatomical structures in noncontact ultrasound examinations. Neonates with suspected ROP could be screened with B-scan ultrasonography by neonatal personnel without pupillary dilatation or lid speculum, thus eliminating potential morbidity, and clinically significant cases of ROP then could be referred to the retinologist.

J Pediatr Ophthalmol Strabismus
2004;41:345–350.
Management of the Anterior and Posterior Lens Capsules and Vitreous in Pediatric Cataract Surgery
Authors: Guo Suqin , Wagner Rudolph S. , Caputo Anthony 
Published: January 2019

Educational Objectives

1.
To review the literature related to the varieties of methods for managing anterior and posterior lens capsules and vitreous in pediatric cataract surgery.

2.
To describe the characteristics of pediatric cataracts and their unique responses to different types of surgical managements.

3.
To discuss our experience in managing anterior and posterior lens capsules and vitreous in pediatric cataract surgery.

See quiz on page 356; no payment required.

Purpose:
To review and discuss the advantages and disadvantages of various methods of managing anterior and posterior lens capsules and anterior vitreous in pediatric cataract surgery.

Methods:
We reviewed the literature related to pediatric cataract surgery on PubMed and subclassified the subject into subtopics for managing the anterior lens capsule, posterior lens capsule, and anterior vitreous.

Results:
After a review of the literature, we summarized the advantages and disadvantages of various approaches related to surgical managements of the anterior lens capsule, posterior lens capsule, and anterior vitreous in pediatric cataract surgery. We discussed recommendations from the literature and commented on our experiences related to the above subtopics.

Conclusion:
In the surgical management of pediatric cataract, anterior continuous curvilinear capsulorhexis provides the most reliable and tear-resistant capsular opening. Vitrectorhexis and radiofrequency diathermy, on the other hand, are alternative approaches (depending on the surgeon’s personal preference). Primary posterior continuous curvilinear capsulorhexis may delay the onset of posterior capsule opacification. Anterior vitrectomy may be necessary to prevent or eliminate the onset of posterior capsule opacification in young children.

J Pediatr Ophthalmol Strabismus
2004;41:330–337.