TITLE:   GCN CIRCULAR
NUMBER:  16505
SUBJECT: GRB140703A: 10.4m GTC redshift
DATE:    14/07/03 07:04:51 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

A. J. Castro-Tirado (IAA-CSIC), R. Cunniffe (IAA-CSIC), R. Sanchez-Ramirez (IAA-CSIC), J. Gorosabel (IAA-CSIC/UPV-EHU), M. Jelinek (IAA-CSIC), S.R. Oates (IAA-CSIC), S. Jeong (IAA-CSIC), J. R. Tello (IAA-CSIC), S. Pandey (ARIES), G. Gomez-Velarde (GTC, IAC), A. Perez (GTC), report on behalf of a larget collaboration:

"We obtained 2x450s optical spectra  of GRB 140703A (Kocevski et al. GCN16503) optical afterglow (Cunniffe et al. GCN16504) with the 10.4m GTC(+OSIRIS) with a wavelength coverage of 4000--9500 AA based on R1000R and R1000B grisms. The combined spectrum shows a deep Lyman-alpha absorption and many metallic absorption lines (AlI, CII, CIV,AlIII..). Using archival calibration lamps  we infer a common redshift of z=3.14."

[GCN OPS NOTE(03jul14):  Per author's request, G.G-V & A.P. were added to the author list.]