GCN Circular 8495
Subject
GRB 081105B: Fermi GBM detection
Date
2008-11-07T17:01:51Z (16 years ago)
From
Andreas von Kienlin at MPE <azk@mpe.mpg.de>
Elisabetta Bissaldi (MPE) and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team:
"At 14:43:51.29 UT on 05 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081105B (trigger 247589032 / 081105614).
The on-ground calculated location, using the GBM trigger
data, is RA = 215.7 deg, Dec = 42.8 (J2000 degrees,
equivalent to 14h 23m, 42d 48'), with an uncertainty
of 12 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 87 degrees.
This short GRB consists of a single peak with an estimated
T90 (8-1000 keV) of 180 ms and T50 (8-1000 keV) of 64 ms.
The spectral fit to this weak event is poorly constrained.
A fit of the time-averaged spectrum from T0-0.067 s to T0-0.019 s
by a simple power law function yields an index of -1.17 +/- 0.05
(chi squared 311 for 421 d.o.f.).
The event fluence (8-1000 keV) in this time interval is
(2.28 +/- 0.11)E-07 erg/cm^2. The photon flux on the
16 ms timescale measured starting from T0-0.067 s
in the 8-1000 keV band is 20 +/- 3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."