GCN Circular 1058
Subject
GRB010427, Gamma Ray Observations
Date
2001-05-04T08:07:06Z (24 years ago)
From
Srikanta Sinha at ISRO/ISAC <sinha@isac.ernet.in>
S.Sinha,P.Sreekumar,K.Kasturirangan, on behalf of SROSS C-2 (INDIAN GRB
EXPERIMENT) team report:
SROSS C-2 observed this burst at 67456.453 secs U.T (this time is
not corrected for some systematic errors). As observed by SROSS C-2, it
had a duration (T90) of 1.20 +- 0.05 secs. Its fluence in the 20-100 keV
band is equal to 1.41.10-7 +- 2.0.10-8 ergs cm-2 and in the 100-1024 keV
band is equal to 5.59.10-5 +- 2.35. 10-6 ergs cm-2 respectively. These
fluences are not corrected for the cos(theta) factor since the direction
to this burst is not known to us yet. The peak flux (256 ms) in the
20-100 keV band is 4.73 photons cm-2 sec-1 and the peak flux (256 ms) in
the 100-1024 keV band is 6.29 photons cm-2 sec-1. The hardness ratio for
this burst (when the signal peaks in the 100-1024 keV channel) is equal
to 0.56 +- 0.15. Our hardness ratio is defined as [counts(100-1024
keV)/counts (20-100 keV)]. For 21 SROSS C-2 GRBs that have common BATSE
triggers, we find the mean hardness ratio is 0.97 +- 0.08 and the std.
deviation of the hardness distribution is equal to 0.37.
This message is citable.
-Srikanta Sinha, on behalf of the SROSS C-2 (INDIAN GRB EXPT. TEAM) at
the Technical Physics Division, ISRO Satellite Center, Bangalore-560 017,
INDIA.
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