GCN Circular 1104
Subject
GRB010923 as seen by BeppoSAX GRBM
Date
2001-10-01T19:01:06Z (23 years ago)
From
Cristiano Guidorzi at Phys.Dept, U.of Ferrara(Italy) <guidorzi@fe.infn.it>
E. Montanari, C. Guidorzi and F. Frontera, Physics Dept, University of
Ferrara; L. Amati, ITESRE, CNR, Bologna, on behalf of the GRBM BeppoSAX
team, report:
The gamma-ray burst GRB010223 reported by the HETE team (GCN/HETE_POSITION
H1764, GCN 1102) was also detected by the BeppoSAX GRBM (units 1 and 4)
with onset at 09:24:29 UT of September 23, 2001. The event was classified
(GCN 1102) as short (<1 s) GRB. However, on the basis of the GRBM data, in
addition to the double peak structure reported by HETE, the 40-700 keV
time profile shows another peak starting 2 s after the burst onset, and
lasting ~2 s. The time duration in terms of T90 is thus found to be ~4 s.
The FWHM of the first two peaks also detected by HETE are estimated about
200 ms and 350 ms, respectively. The total counts collected during the
event are 2680, with 540 cts in the first peak, 1600 cts in the second one
and 540 cts in the last peak.
A preliminary spectral analysis shows that the total fluence in the 80-600
keV range is about 2.5 x 10-6 ergs cm-2. The spectral hardness, as
estimated from the ratio between the 100-700 keV counts and those in the
40-100 keV band, looks softer than typical short bursts.
From GRBM data we derived the following rough position: R.A. = 312 deg,
Decl.= +17 deg, with an error radius of 25 deg (inclusive of 10 deg
systematics).
In summary, GRBM data suggest that GRB010923 is more likely to
be an "intermediate" burst, both for its time duration and its spectral
hardness.
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