D. Xu (DARK/NBI), D. Malesani (DARK/NBI), S. Schulze (PUC and MCSS),
J. P. U. Fynbo (DARK/NBI), Valerio D'Elia (ASI-SDC, INAF OAR), P.
Goldoni (APC/Univ. Paris 7 and SAp/CEA), O. Hartoog (Amsterdam), J.
Hjorth (DARK/NBI), L. Kaper (Amsterdam), T. Kruehler (DARK/NBI), A. J.
Levan (U. Warwick), B. Milvang-Jensen (DARK/NBI), N. R. Tanvir (U.
Leicester), K. Wiersema (U. Leicester) report on behalf of the
X-shooter GRB GTO collaboration:
We observed the optical afterglow of GRB 130606A (Ukwatta et al., GCN
14781; Jelinek et al., GCN 14782; Xu et al., GCN 14783) using the ESO
VLT equipped with the X-shooter spectrograph. The observations started
on 2013-06-07 at 04:09 UT (i.e., 7.08 hr after the burst). A total
exposure of 6x600 s was obtained, covering the spectral range from
~3000 to ~21000 A.
A continuum is detected redward of ~8410 A in the VIS/NIR arms of the
spectra, consistent with a Lyman alpha dropout at z~5.9, while
discrete transmission is present blueward down to ~6505 A. In the
spectra prominent absorption lines are detected, such as NV, C II, O
I, Si IV, C IV, and Si II, all at a common redshift of z=5.913, fully
consistent with the measurements in Castro-Tirado et al. (GCN 14796)
and Lunnan et al. (GCN 14798). We also identified at least two
intervening absorbers at z=3.451 and at z=2.310 through Mg II and Fe
We thank the Paranal staff for enthusiastic support, in particular
Cedric Ledoux and Felipe Gaete.