{
  "bibcode": "2011GCN.12431....1W",
  "body": "K. Wiersema (Univ. Leicester), H. Flores (GEPI/Obs. de Paris), V. D'Elia \n(ASI/ASDC & INAF/OAR), P. Goldoni (APC/Univ. Paris 7 & SAp/CEA), D. \nMalesani (DARK/NBI), S. D. Vergani (INAF/OABr), A. de Ugarte Postigo \n(IAA-CSIC), A. J. Levan (Univ. Warwick), B. Milvang-Jensen, J. P. U. \nFynbo (DARK/NBI), report on behalf of a larger collaboration:\n\nWe observed the optical counterpart of GRB 111008A (Saxton et al., GCN \n12423; Levan et al., GCN 12426; Xu et al., GCN 12427; Nardini et al., \nGCN 12428), using the X-shooter spectrograph mounted on the ESO-VLT. \nObservations started on 2011 October 9.247 UT (7.71 hr after the GRB), \nwith a total exposure time of 2 hr, covering the wavelength range \n3000-25000 AA.\n\nContinuum is clearly detected  redwards of ~7600 AA, with several, \nstrong superimposed absorption features, consistent with a commom \nredshift z = 4.9898. Among them, we note several Si II and Fe II \ntransitions, the CIV doublet, the Mg II doublet (in the H band), and \nseveral fine-structure lines commonly observed in GRB afterglow spectra \n(such as Si II*, S II*, O I*). We also note the presence of an \nintervening Mg II system at z = 4.61. Our results are thus consistent \nwith the redshift derived by Levan et al. (GCN 12429; see also Nardini \net al., GCN 12428).\n\nWe acknowledge excellent support from the observing staff in Paranal, in \nparticular Christophe Martayan, Claudio Melo, Leonel Rivas, and Sergio Vera.",
  "circularId": 12431,
  "createdOn": 1318158184000,
  "email": "malesani@dark-cosmology.dk",
  "subject": "GRB 111008A: VLT/X-shooter spectroscopy",
  "submitter": "Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>",
  "eventId": "GRB 111008A"
}