@article{BersierFruchterStrolgeretal.2006,
  author    = {Bersier, David and Fruchter, Andrew S. and Strolger, Louis-Gregory and Gorosabel, Javier and Levan, Andrew and Burud, Ingunn and Rhoads, James E. and Becker, Andrew C. and Cassan, Andrew C. and Chornock, Ryan and Covino, Stefano and De Jong, Roelof S. and Dominis, Dijana and Filippenko, Alexei V. and Hjorth, Jens and Holmberg, Johan and Malesani, Daniele and Mobasher, Bahram and Olsen, Kurt A. G. and Stefanon, Mauro and Castro Cer{\´o}n, Jos{\´e} Mar{\´i}a C. and Fynbo, Johan P. U. and Holland, Stephen T. and Kouveliotou, Chryssa and Pedersen, Hans-Georg and Tanvir, Nieal R. and Woosley, S. E.},
  title     = {Evidence for a supernova associated with the X-ray flash 020903},
  issn      = {0004-637X},
  doi       = {10.1086/502640},
  year      = {2006},
  abstract  = {We present ground-based and Hubble Space Telescope optical observations of the X-ray flash ( XRF) 020903, covering 300 days. The afterglow showed a very rapid rise in the first day, followed by a relatively slow decay in the next few days. There was a clear bump in the light curve after similar to 25 days, accompanied by a drastic change in the spectral energy distribution. The light curve and the spectral energy distribution are naturally interpreted as describing the emergence and subsequent decay of a supernova ( SN), similar to SN 1998bw. At peak luminosity, the SN is estimated to be 0.8 +/- 0.1 mag fainter than SN 1998bw. This argues in favor of the existence of a SN associated with this XRF. A spectrum obtained 35 days after the burst shows emission lines from the host galaxy. We use this spectrum to put an upper limit on the oxygen abundance of the host at [O/H] <= 0.6 dex. We also discuss a possible trend between the softness of several bursts and the early behavior of the optical afterglow, in the sense that XRFs and X-ray-rich gamma- ray bursts ( GRBs) seem to have a plateau phase or even a rising light curve. This can be naturally explained in models in which XRFs are similar to GRBs but are seen off the jet axis.},
  language  = {en}
}
@article{SelsingMalesaniGoldonietal.2019,
  author    = {Selsing, Jonatan and Malesani, D. and Goldoni, P. and Fynbo, Johan and Kr{\"u}hler, T. and Antonelli, L. A. and Arabsalmani, M. and Bolmer, J. and Cano, Z. and Christensen, L. and Covino, S. and De Cia, A. and de Ugarte Postigo, A. and Flores, H. and Fliis, M. and Gomboc, A. and Greiner, J. and Groot, P. and Hammer, F. and Hartoog, O. E. and Heintz, K. E. and Hjorth, J. and Jakobsson, P. and Japelj, J. and Kann, D. A. and Kaper, L. and Ledoux, C. and Leloudas, G. and Levan, A. J. and Maiorano, E. and Melandri, A. and Milvang-Jensen, B. and Palazzi, E. and Palmerio, J. T. and Perley, D. A. and Pian, E. and Piranomonte, S. and Pugliese, G. and Sanchez-Ramirez, R. and Savaglio, S. and Schady, P. and Schulze, S. and Sollerman, J. and Sparre, Martin and Tagliaferri, G. and Tanvir, N. R. and Thone, C. C. and Vergani, S. D. and Vreeswijk, P. and Watson, D. and Wiersema, K. and Wijers, R. and Xu, D. and Zafar, T.},
  title     = {The X-shooter GRB afterglow legacy sample (XS-GRB)},
  series = {Astronomy and astrophysics : an international weekly journal},
  volume    = {623},
  journal   = {Astronomy and astrophysics : an international weekly journal},
  publisher = {EDP Sciences},
  address   = {Les Ulis},
  issn      = {1432-0746},
  doi       = {10.1051/0004-6361/201832835},
  pages     = {42},
  year      = {2019},
  abstract  = {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.},
  language  = {en}
}