TY  - JOUR
A1  - Selsing, Jonatan
A1  - Malesani, D.
A1  - Goldoni, P.
A1  - Fynbo, Johan
A1  - Krühler, T.
A1  - Antonelli, L. A.
A1  - Arabsalmani, M.
A1  - Bolmer, J.
A1  - Cano, Z.
A1  - Christensen, L.
A1  - Covino, S.
A1  - De Cia, A.
A1  - de Ugarte Postigo, A.
A1  - Flores, H.
A1  - Fliis, M.
A1  - Gomboc, A.
A1  - Greiner, J.
A1  - Groot, P.
A1  - Hammer, F.
A1  - Hartoog, O. E.
A1  - Heintz, K. E.
A1  - Hjorth, J.
A1  - Jakobsson, P.
A1  - Japelj, J.
A1  - Kann, D. A.
A1  - Kaper, L.
A1  - Ledoux, C.
A1  - Leloudas, G.
A1  - Levan, A. J.
A1  - Maiorano, E.
A1  - Melandri, A.
A1  - Milvang-Jensen, B.
A1  - Palazzi, E.
A1  - Palmerio, J. T.
A1  - Perley, D. A.
A1  - Pian, E.
A1  - Piranomonte, S.
A1  - Pugliese, G.
A1  - Sanchez-Ramirez, R.
A1  - Savaglio, S.
A1  - Schady, P.
A1  - Schulze, S.
A1  - Sollerman, J.
A1  - Sparre, Martin
A1  - Tagliaferri, G.
A1  - Tanvir, N. R.
A1  - Thone, C. C.
A1  - Vergani, S. D.
A1  - Vreeswijk, P.
A1  - Watson, D.
A1  - Wiersema, K.
A1  - Wijers, R.
A1  - Xu, D.
A1  - Zafar, T.
T1  - The X-shooter GRB afterglow legacy sample (XS-GRB)
JF  - Astronomy and astrophysics : an international weekly journal
N2  - In this work we present spectra of all gamma-ray burst (GRB) afterglows that have been promptly observed with the X-shooter spectrograph until 31/03/2017. In total, we have obtained spectroscopic observations of 103 individual GRBs observed within 48 hours of the GRB trigger. Redshifts have been measured for 97 per cent of these, covering a redshift range from 0.059 to 7.84. Based on a set of observational selection criteria that minimise biases with regards to intrinsic properties of the GRBs, the follow-up effort has been focused on producing a homogeneously selected sample of 93 afterglow spectra for GRBs discovered by the Swift satellite. We here provide a public release of all the reduced spectra, including continuum estimates and telluric absorption corrections. For completeness, we also provide reductions for the 18 late-time observations of the underlying host galaxies. We provide an assessment of the degree of completeness with respect to the parent GRB population, in terms of the X-ray properties of the bursts in the sample and find that the sample presented here is representative of the full Swift sample. We have constrained the fraction of dark bursts to be <28 per cent and confirm previous results that higher optical darkness is correlated with increased X-ray absorption. For the 42 bursts for which it is possible, we have provided a measurement of the neutral hydrogen column density, increasing the total number of published HI column density measurements by similar to 33 per cent. This dataset provides a unique resource to study the ISM across cosmic time, from the local progenitor surroundings to the intervening Universe.
KW  - gamma-ray burst: general
KW  - galaxies: high-redshift
KW  - ISM: general
KW  - techniques: spectroscopic
KW  - catalogs
KW  - galaxies: star formation
Y1  - 2019
U6  - https://doi.org/10.1051/0004-6361/201832835
SN  - 1432-0746
SN  - 0004-6361
VL  - 623
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Heintz, Kasper Elm
A1  - Watson, D.
A1  - Jakobsson, P.
A1  - Fynbo, J. P. U.
A1  - Bolmer, J.
A1  - Arabsalmani, M.
A1  - Cano, Zach
A1  - Covino, S.
A1  - Gomboc, A.
A1  - Japelj, J.
A1  - Kaper, L.
A1  - Krogager, J. -K.
A1  - Pugliese, G.
A1  - Sanchez-Ramirez, R.
A1  - Selsing, J.
A1  - Sparre, Martin
A1  - Tanvir, N. R.
A1  - Thone, C. C.
A1  - de Ugarte Postigo, A.
A1  - Vergani, S. D.
T1  - Highly ionized metals as probes of the circumburst gas in the natal regions of gamma-ray bursts
JF  - Monthly notices of the Royal Astronomical Society
N2  - We present here a survey of high-ionization absorption lines in the afterglow spectra of long-duration gamma-ray bursts (GRBs) obtained with the VLT/X-shooter spectrograph. Our main goal is to investigate the circumburst medium in the natal regions of GRBs. Our primary focus is on the N vλλ 1238, 1242 line transitions, but we also discuss other high-ionization lines such as O vi, C iv, and Si iv. We find no correlation between the column density of N v and the neutral gas properties such as metallicity, H i column density, and dust depletion; however, the relative velocity of N v, typically a blueshift with respect to the neutral gas, is found to be correlated with the column density of H i. This may be explained if the N v gas is part of an H ii region hosting the GRB, where the region’s expansion is confined by dense, neutral gas in the GRB’s host galaxy. We find tentative evidence (at 2σ significance) that the X-ray derived column density, NH, X, may be correlated with the column density of N v, which would indicate that both measurements are sensitive to the column density of the gas located in the vicinity of the GRB. We investigate the scenario where N v (and also O vi) is produced by recombination after the corresponding atoms have been stripped entirely of their electrons by the initial prompt emission, in contrast to previous models where highly ionized gas is produced by photoionization from the GRB afterglow.
KW  - gamma-ray bursts: general
KW  - ISM: abundances
Y1  - 2018
U6  - https://doi.org/10.1093/mnras/sty1447
SN  - 0035-8711
SN  - 1365-2966
VL  - 479
IS  - 3
SP  - 3456
EP  - 3476
PB  - Oxford Univ. Press
CY  - Oxford
ER  -