[vsnet-grb-info 13457] GRB 130606A: 10.4m GTC spectroscopy indicates z = 6.1

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14790
SUBJECT: GRB 130606A: 10.4m GTC spectroscopy indicates z = 6.1
DATE:    13/06/07 00:06:12 GMT
FROM:    Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct at iaa.es>

A. J. Castro-Tirado, R. Sánchez-Ramírez, M. Jelinek (IAA-CSIC), J.
Gorosabel (EHU-UPV), J. C. Tello, P. Ferrero, O. Lara-Gil, R. Cunniffe
(IAA-CSIC), D. Pérez-Ramírez (U. Jaén), P. Kubanek (FZU), J. M. Castro
Cerón (ESAC), A. Fernández-Soto (UV), S. Mottola (DLR), S. Hellmich (DLR),
R. Fernández-Muñoz (EELM-CSIC), V. F. Muñoz-Martínez (UMA), J. Cepa (IAC)
and C. Álvarez-Iglesias (GTC), on behalf of a larger collaboration,
report:

“Following the detection of the optical afterglow (Jelinek et al. GCNC
14782, Xu et al. GCNC 14783) to GRB 130606A ((Ukwatta et al. GCNC
14781), we have obtained an optical spectrum with the 10.4 m GTC (+OSIRIS)
starting aprox. 1.5 hr postburst, covering the 4000-10000 wavelength
range. The continuum is detected only redwards of aprox. 6500 A, with
multiple absorption lines which are indicative of the Lyman forest.
Therefore we infer a (preliminary) redshift of z = 6.1 (to be refined).
This is consistent with the dropout in the optical band (Virgili et al.
GCNC 14785) and the bright nIR afterglow (Nagayama et al. GCNC 14784).
Observations at all wavelengths are encouraged.”