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The high-redshift gamma-ray burst GRB 140515A. A comprehensive X-ray and optical study

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TLDR
In this paper, a multi-wavelength analysis of the high-zSwift gamma-ray burst (GRB) 140515A (z = 6.327) is presented.
Abstract
High-redshift gamma-ray bursts (GRBs) offer several advantages when studying the distant Universe, providing unique information about the structure and properties of the galaxies in which they exploded. Spectroscopic identification with large ground-based telescopes has improved our knowledge of this kind of distant events. We present the multi-wavelength analysis of the high-zSwift GRB GRB 140515A (z = 6.327). The best estimate of the neutral hydrogen fraction of the intergalactic medium towards the burst is xHI ≤ 0.002. The spectral absorption lines detected for this event are the weakest lines ever observed in GRB afterglows, suggesting that GRB 140515A exploded in a very low-density environment. Its circum-burst medium is characterised by an average extinction (AV ~ 0.1) that seems to be typical of z ≥ 6 events. The observed multi-band light curves are explained either with a very hard injected spectrum (p = 1.7) or with a multi-component emission (p = 2.1). In the second case a long-lasting central engine activity is needed in order to explain the late time X-ray emission. The possible origin of GRB 140515A in a Pop III (or in a Pop II star with a local environment enriched by Pop III) massive star is unlikely.

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A comprehensive statistical study on gamma-ray bursts

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The fraction of ionizing radiation from massive stars that escapes to the intergalactic medium

TL;DR: In this article, the authors present a compilation of H i column density (N HI ) measures for 140 gamma-ray burst (GRB) afterglows in the range 1.6 < z < 6.7.
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A Comparative Study of Long and Short GRBs. I. Overlapping Properties

TL;DR: In this article, the authors performed a comprehensive multi-wavelength comparative study between duration-defined long GRBs and short GRBs as well as the so-called consensus GRBs, which are believed to be more closely related to the two types of progenitor systems.
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The X-shooter GRB afterglow legacy sample (XS-GRB)

Jonatan Selsing, +66 more
TL;DR: In this paper, the authors presented spectra of all γ-ray burst (GRB) afterglows that have been promptly observed with the X-shooter spectrograph until 31/03/2017.
References
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Journal ArticleDOI

The relationship between infrared, optical, and ultraviolet extinction

TL;DR: In this article, the average extinction law over the 3.5 micron to 0.125 wavelength range was derived for both diffuse and dense regions of the interstellar medium. And the validity of the law over a large wavelength interval suggests that the processes which modify the sizes and compositions of grains are stochastic in nature.
Journal ArticleDOI

Measuring Reddening with Sloan Digital Sky Survey Stellar Spectra and Recalibrating SFD

TL;DR: In this paper, the authors measured the difference between the measured and predicted colors of a star, as derived from stellar parameters from the Sloan Extension for Galactic Understanding and Exploration Stellar Parameter Pipeline, and achieved uncertainties of 56, 34, 25, and 29 mmag in the colors u − g, g − r, r − i, and i − z, per star.
Journal ArticleDOI

Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD

TL;DR: Lee et al. as discussed by the authors measured the difference between the measured and predicted colors of a star, as derived from stellar parameters from the SEGUE Stellar Parameter Pipeline, and achieved uncertainties of 56, 34, 25, and 29 mmag in the colors u-g, g-r, r-i, and i-z, per star.
Journal ArticleDOI

The Swift Gamma-Ray Burst Mission

Neil Gehrels, +77 more
TL;DR: The Swift mission as discussed by the authors is a multi-wavelength observatory for gamma-ray burst (GRB) astronomy, which is a first-of-its-kind autonomous rapid-slewing satellite for transient astronomy and pioneers the way for future rapid-reaction and multiwavelength missions.
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