GCN Circular 2215

Michael Weidinger, Johan P. U. Fynbo (U. of Aarhus), Jens Hjorth 
(U. of Copenhagen), Javier Gorosabel (IAA-CSIC/STScI), Sylvio Klose 
(TLS Tautenburg), Nial Tanvir (U. of Hertfordshire) report on behalf of the 
GRACE collaboration:

"Further analysis of the VLT spectra of the afterglow of GRB 030429 
(GCN 2184
Not found
 
 
) and the neighbor galaxy at a separation of 1.2 arcsec from the 
afterglow (GCN 2185
Not found
 
 
, 2196
Not found
 
 
) has led to the following conclusions. Based on 
absorption lines due to HI, OI, SiII, and CII we infer a redshift of 
z=2.6564+/-0.0008 for GRB 030429. Based on a single, weak emission line in 
the spectrum of the neighbor galaxy, which we interpret as [OII], and weak 
Calcium H and K absorption we infer a redshift of z=0.841+/-0.001 for the 
galaxy. This is consistent with the redshift of an absorption line in the 
spectrum of the afterglow if interpreted as MgII. This galaxy is therefore 
not the host galaxy of the GRB. In deep images obtained with the VLT/FORS2 
on May 5 the afterglow is only barely detected. We do not find any evidence 
for a host galaxy at the position of the afterglow to R>25. The separation 
between the position of the afterglow and the z=0.841 neighbor galaxy of 1.2 
arcsec is comparable to the Einstein radius for a massive galaxy at that 
redshift. Gravitational lensing could therefore affect the appearance of 
GRB 030429.

We acknowledge excellent support from the Paranal Observatory staff."