TITLE:   GCN CIRCULAR
NUMBER:  13217
SUBJECT: GRB 120404A: Gemini-N Redshift correction
DATE:    12/04/04 18:38:17 GMT
FROM:    Antonino Cucchiara at UCSC/UCO Lick  <acucchia@ucolick.org>

A. Cucchiara (UCSC/UCO Lick), N.R. Tanvir (U. of Leicester) report
on behalf of a larger collaboration:

We re-analyzed the GMOS spectra of GRB 120404A presented 
in GCN 13213.
Based on further analysis we report a corrected redshift 
for the GRB of z=2.876. 

This new value is based on the identification of SiIV1393,1403,
CIV1550,AlIII1855,1963, CII1335, CII*1335, SiII1527, SiII*1533,
SiII1808.
We note that the CIV1448 line at this redshift is partly covered
by the GMOS chip gap.

At least four different intervening systems are identified at 
the following redshifts:

z1=2.551 (based on CIV1548,1550 doublet)
z2=1.776 (based on MgII2796,2803 doublet)
z3=1.633 (based on MgII2796,2803 doublet)
z4=1.101 (based on MgII2796,2803 doublet)

We encourage further spectroscopic observations and apologize for
any inconvenience the previous redshift determination may have caused.