GCN Circular 2196
Subject
GRB 030429: redshift from VLT spectroscopy
Event
Date
2003-05-02T15:01:22Z (22 years ago)
From
Johan U. Fynbo at IFA,U of Aarhus <jfynbo@phys.au.dk>
Michael Weidinger, Johan P. U. Fynbo (U. of Aarhus), Jens Hjorth
(U. of Copenhagen), Javier Gorosabel (IAA-CSIC/STScI), Paul Vreeswijk
(ESO Chile), Sylvio Klose (TLS Tautenburg) report on behalf of the
GRACE collaboration:
"We have observed the field of GRB 030429 (=HETE trigger 2695) around
May 2.2 UT with the ESO VLT. Using FORS1 on UT1 we have obtained a
spectrum of the optical afterglow (GCN 2184) covering 3800 - 8000
Angstrom. In the spectrum we identify a strong damped Ly-alpha line
around 4442 Angstrom. This implies a lower limit of z=2.65 to the
redshift of GRB 030429. The absence of Ly-alpha forest absorption on
the red side of the line and the seemingly very large column density
of the line renders a higher redshift very unlikely and we therefore
conclude that z=2.65 is the redshift of GRB 030429.
We acknowledge excellent support from Cedric Ledoux, Rachel Johnson,
Poshak Gandhi and Elena Mason at the Paranal Observatory."