[vsnet-grb-info 3314] GRB 060512: reanalysis of optical spectra

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5149
SUBJECT: GRB 060512: reanalysis of optical spectra
DATE:    06/05/19 13:08:08 GMT
FROM:    Rhaana Starling at GRACE/U of Amsterdam  <starling at science.uva.nl>

R. Starling (Amsterdam), V. D'Elia (INAF/OARm), S. Piranomonte
(INAF/OARm), J.P.U. Fynbo (DARK), D. Malesani (SISSA/ISAS),
C.C. Thoene (DARK), J. Hjorth (DARK), P. Vreeswijk (ESO), F. Fiore
(INAF/OARm), E. Maiorano (INAF/IASF Bo), N. Masetti (INAF/IASF Bo),
report:

Following further analysis of the optical spectra of GRB 060512
(Cummings et al., GCN 5117) taken with TNG+DOLoRes (Piranomonte et al.,
GCN 5145) and VLT+FORS1 (Starling et al., GCN 5131), we issue a
retraction of the redshift range estimated in GCN 5131, which arose
from an error in the preliminary flux calibration.

In both the TNG and the VLT spectra we see no break in the continuum
emission and no obvious features in either absorption or emission.

A possible solution might be z~2.1, based only, however, on a low
significance, broad feature in absorption seen at the bluemost limit
of the TNG spectrum which, if identified as Lyman-alpha 1215A, implies
this redshift. A plot of the TNG spectrum can be found here:
http://www.sissa.it/~malesani/GRB/060512/spec_TNG.gif