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GCN Circular 10350

GRB091109A: VLT/FORS2 spectroscopic redshift
2010-01-19T22:11:33Z (14 years ago)
Arne Rau at MPE <>
Arne  Rau (MPE  Garching), Johan Fynbo (DARK), and Jochen Greiner (MPE 

"We report on additional analysis of our VLT/FORS2 spectrum of the 
optical afterglow of GRB 091109A (Oates et al., GCN #10138, Guidorzi et 
al. GCN#10142, Oates GCN#10143, Afonso et al., GCN #10158 ).

A careful search revealed  absorption lines at 6227, 6308, and 6321 
Angstroem  which we identify with  SiII  and the CIV doublet a common 
redshift of  z=3.076 +/- 0.002.  Lyman-alpha absorption at this redshift 
is located shortwards of the blue wavelength cut-off and the earlier 
reported tentative detection at 5700A (Afonso et al., GCN #10158) is not 
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