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GCN Circular 13217

GRB 120404A: Gemini-N Redshift correction
2012-04-04T18:38:17Z (12 years ago)
Antonino Cucchiara at UCSC/UCO Lick <>
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,
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.
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