GCN Circular 4032
Subject
GRB050922C: TNG spectroscopic observations
Date
2005-09-23T17:37:41Z (19 years ago)
From
Silvia Piranomonte at OAR <piranomonte@mporzio.astro.it>
S. Piranomonte (INAF/OAR), A. Magazzu (TNG), G. Mainella (TNG),
F. Fiore (INAF/OAR), S. Covino (INAF/OABr), D. Fugazza (INAF/OABr),
A. Antonelli (INAF/OAR), G. Israel (INAF/OAR), G. Chincarini (Univ. Milano-Bicocca),
D. Malesani (SISSA), , F. Mannucci (INAF/Arcetri), G. Tagliaferri (INAF/OABr),
and L. Stella (INAF/OAR) on behalf of the CIBO collaboration, report:
Starting on September 22 21:17:35 UT (about 82 min after the GRB
trigger) we have obtained low resolution spectra
of the optical afterglow of GRB050922C (Rykoff et al.
GCN#4012). The observations consisted of 5 exposures for 300 sec each with
DOLORES@TNG, using grism LR-B, with a 1" slit. This set-up provides
a resolution of about 5 angstrom.
At the time of the observations the afterglow magnitude varied between
R~16.7 and R=17.7.
A preliminary analysis of the data confirms a very rich spectrum
(see Jakobsson et al. GCN#4017, GCN#4029).
We detect strong Lyalpha, SiII1304, CII1334, SiIV1393, SiII1526,
CIV1548,1550, AlII1670, SiII1808 absorption lines at z=2.198+/-0.001,
We also confirm the strong Lyalpha absorption at z=2.07.
A full analysis is underway.
We thank the TNG staff for the excellent support in performing these
observations.
This message can be quoted.