D. Xu (DARK/NBI), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), D. Malesani (DARK/NBI), P. Vreeswijk (Weizmann), V. D'Elia (INAF-OAR, ASI-ASDC), J. P. U. Fynbo (DARK/NBI), B. Milvang-Jensen (DARK/NBI), H. Flores (GEPI/Obs. de Paris), O. Hartoog (Amsterdam), P. Goldoni (APC, CEA/Irfu), L. Kaper (Amsterdam), S. D. Vergani (CNRS/GEPI)
We observed the afterglow of GRB 130701A (Kuin et al. GCN 14953, Leloudas et al. GCN 14954) with VLT/X-shooter, beginning at 2013-07-01 09:45 UT, about 5.5 hours after the burst. We obtained 2 spectra of 600s each, covering the wavelength range 3000-21000A.
From the acquisition image (Jul 1.404 UT, 5.40 hr after the GRB) we obtain a magnitude of R = 19.9 using the same calibration as in Leloudas et al. (GCN 14954).
Preliminary analysis of the spectrum reveals absorption lines of FeII
2344, 2374, 2382, MgII 2796, 2803, MgI 2852, CaII 3934, 3969 at a common redshift of z=1.155. We propose this to be the redshift of the GRB.
We thank the staff at Paranal, particularly Jonathan Smoker and Nestor Jimenez, for obtaining these observations.
[GCN OPS NOTE(01jul13) Per A.Breeveld's observation, the GRB name in the Subject-line was corrected.]