GCN Circular 9381
Subject
GRB 090516: VLT redshift
Date
2009-05-17T02:47:56Z (16 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (ESO), J. Gorosabel (IAA/CSIC), D. Malesani,
J.P.U. Fynbo (DARK/NBI), A. J. Levan (Univ. Warwick), report on
behalf of a larger collaboration:
We observed the optical afterglow of GRB 090516 (Rowlinson et al.,
GCN 9374; Guidorzi et al., GCN 9375) with the ESO VLT equipped
with FORS2. Observations started on 2009 May 16.989 UT (15.1 hr
after the GRB). In the acquisition image, the afterglow is well detected
with R ~ 21.2, consistent with the NOT measurement (Gorosabel et al.,
GCN 9379).
Two spectra lasting 30 min each were acquired with the grism 300V,
covering the wavelength range 3500-9200 AA. In a preliminary analysis
we detect the Lyman limit, a strong Ly-alpha absorption as well as
a number of strong absorption lines (SII, OI, CII, SiIV, CIV, AlII etc.)
at a redshift of z=3.9.
We acknowledge excellent support from the observing staff in Paranal,
in particular Alain Smette, Leo Rivas and Gianni Marconi.