GCN Circular 2015
Subject
GRB030329: optical spectroscopy with the TNG
Event
Date
2003-03-30T05:56:08Z (23 years ago)
From
Angelo Antonelli at Obs. Astro. di Roma <angelo@coma.mporzio.astro.it>
R. Della Ceca, T. Maccacaro (INAF-OABrera), D. Fugazza, M. Pedani,
M. Cecconi (TNG), F. Fiore, L.A. Antonelli (INAF-OAR), S. Covino
(INAF-OABrera), E. Pian (INAF-OATs), N. Masetti (IASF-CNR) report:
"Starting on March 30 2003 00:43:40 UT we have obtained low resolution
(R~1000) spectra of the optical afterglow of GRB030329 (Peterson &
Price GCN #1985, Torii, GCN #1986) using DOLORES at TNG. Observations
consisted of two exposures of 15 min each the second obtained at 2.75hh
after the first, and cover the full spectral range 3800-8000 Angstrom,
in relatively good seeing conditions (1.5"). At the time of the
observations the afterglow magnitude was R~15-16 (e.g. Martini et al.
GCN #2012).
A preliminary analysis of the spectra reveals no strong absorption
features. A more detailed analysis is needed to search for faint
absorption lines. A faint emission line at 5846 Angstrom (see Martini
et al. GCN# 2013) is present in the later spectra, when the afterglow
emission was less strong. If this is [OII] emission from the host
galaxy, then the redshift is z=0.568.
We detect a strong spectral variability between the first spectrum,
when the afterglow was extremely blue, and the second spectrum,
obtained starting from 03:25:35 UT.
We are particularly grateful to the TNG staff for their remarkable
support to these observations.
This message may be cited."