GCN Circular 1889
Subject
GRB030226: ESI spectroscopy
Event
Date
2003-02-26T21:53:17Z (23 years ago)
From
Derek Fox at CIT <derekfox@astro.caltech.edu>
P.A. Price (RSAA,ANU), D.W. Fox and S.G. Djorgovski (Caltech), M. West
(UH Hilo), and P. Cote and A. Jordan (Rutgers) report on behalf of the
Caltech-NRAO-CARA GRB collaboration:
"We have observed the afterglow of GRB 030226 (Suzuki et al. GCN 1888;
see also GCNs 1879,1880) with the Echellette Spectrograph and Imager
on the Keck II 10-m telescope, in a single 2700-s integration
beginning at 08:00 UT on Feb 26, which provides a high-resolution
(R~5,000) spectrum with high S/N. In a preliminary analysis of the
data, we identify three absorption systems at z=1.984, z=1.961, and
z=1.043. The two higher-redshift systems have been reported
independently by Greiner et al. (GCN 1886), expanding on the initial
reports of Ando et al. (GCN 1884).
For the higher-redshift systems we detect Mg II 2795,2803; Al II 1671;
Al III 1863; Si II 1527; Si IV 1394 and 1403; C IV 1548,1551; and
various Mn II and Fe II lines. For the z=1.043 system, we detect Mg
II 2795,2803, and possibly some Fe II lines.
The two higher-redshift systems exhibit very strong equivalent widths,
whereas the equivalent widths for the z=1.043 system are much weaker,
consistent with the population of field galaxy QSO absorbers.
Moreover, each of the higher-redshift systems, separated by 2300 km/s
in the rest frame, consists of multiple components with further
velocity substructure at the <100 km/s level.
Our results are reminiscent of the findings of several groups with
respect to GRB021004 (Castander et al. GCN 1599, Salamanca et al. GCN
1611, Mirabal et al. GCN 1618, Savaglio et al. GCN 1633, Castro-Tirado
et al. GCN 1635, Moeller et al. astro-ph/0210654, Schaefer et
al. astro-ph/0211189, Wang et al. astro-ph/0301266).
Further analysis of these data and follow-up observations are
ongoing."
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