posted on 2019-06-26, 11:34authored byJ Selsing, D Malesani, P Goldoni, JPU Fynbo, T Kruehler, LA Antonelli, M Arabsalmani, J Bolmer, Z Cano, L Christensen, S Covino, P D'Avanzo, V D'Elia, A De Cia, A de Ugarte Postigo, H Flores, M Fliis, A Gomboc, J Greiner, P Groot, F Hammer, OE Hartoog, KE Heintz, J Hjorth, P Jakobsson, J Japelj, DA Kann, L Kaper, C Ledoux, G Leloudas, AJ Levan, E Maiorano, A Melandri, B Milvang-Jensen, E Palazzi, JT Palmerio, DA Perley, E Pian, S Piranomonte, G Pugliese, R Sanchez-Ramirez, S Savaglio, P Schady, S Schulze, J Sollerman, M Sparre, G Tagliaferri, NR Tanvir, CC Thone, SD Vergani, P Vreeswijk, D Watson, K Wiersema, R Wijers, D Xu, T Zafar
In this work we present spectra of all γ-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 ∼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.
Funding
Much of the work done here would not have been done
without Neil Gehrels, who has now passed away. We owe him a large debt
for his invaluable work with the Swift satellite. We also want to remember
Javier Gorosabel, who was taken from us too early. We thank Andrea Rossi
(INAF/OAS) for the help with providing a photometric constraint on the redshift of GRB 161007A. JPUF, BMJ and DX acknowledge support from the
ERC-StG grant EGGS-278202. The Dark Cosmology Centre was funded by the
Danish National Research Foundation. This work was supported by a VILLUM
FONDEN Investigator grant to JH (project number 16599). TK acknowledges
support by the European Commission under the Marie Curie Intra-European
Fellowship Programme in FP7. LK and JJ acknowledges support from NOVA
and NWO-FAPESP grant for advanced instrumentation in astronomy. KEH
and PJ acknowledge support by a Project Grant (162948–051) from The Icelandic Research Fund. AG acknowledges the financial support from the Slovenian Research Agency (research core funding No. P1-0031 and project grant
No. J1-8136). CT acknowledges support from a Spanish National Research
Grant of Excellence under project AYA 2014-58381-P and funding associated
to a Ramón y Cajál fellowship under grant number RyC-2012-09984. AdUP
acknowledges support from a Ramón y Cajal fellowship, a BBVA Foundation Grant for Researchers and Cultural Creators, and the Spanish Ministry of
Economy and Competitiveness through project AYA2014-58381-P. ZC acknowledges support from the Spanish research project AYA 2014-58381-P and support from Juan de la Cierva Incorporación fellowships IJCI-2014-21669.
DAK acknowledges support from the Spanish research project AYA 2014-
58381-P and support from Juan de la Cierva Incorporación fellowships
IJCI-2015- 26153. RSR acknowledges AdUP’s BBVA Foundation Grant for
Researchers and Cultural Creators and support from ASI (Italian Space Agency)
through the Contract n. 2015-046-R.0 and from European Union Ho
History
Citation
Astronomy and Astrophysics, 2019, 623, A92
Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy
Version
VoR (Version of Record)
Published in
Astronomy and Astrophysics
Publisher
EDP Sciences for European Southern Observatory (ESO)