GCN Circular 8586
Subject
GRB 081129: Fermi GBM detection
Date
2008-12-01T11:08:37Z (16 years ago)
From
Andreas von Kienlin at MPE <azk@mpe.mpg.de>
A. von Kienlin (MPE)
reports on behalf of the Fermi GBM Team:
"At 03:52:04.26 UT on 29 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081129 (trigger 249623525 / 081129161).
The on-ground calculated location, using the GBM trigger
data, is RA = 55.0, DEC = -63.0 (J2000 degrees,
equivalent to 03h 40m, -63d 00'), with an uncertainty
of 1.9 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 118 degrees.
This burst was also independently detected by INTEGRAL SPI-ACS.
The GBM light curve contains 2 peaks and has a duration (T90)
of about 59 s (8-1000 keV) and (T50) of about 17 s (8-1000 keV).
The time-averaged spectrum from T0+0.003 s to T0+59.521 s is
best fit by a Band function with Epeak = 150 +/- 30 keV,
alpha = -0.5 +/- 0.2, and beta = -1.84 +/- 0.08
(chi squared 253 for 233 d.o.f.).
The event fluence (8-1000 keV) in this time interval is
(2.0 +/- 0.3)E-05 erg/cm^2. The 1-sec photon flux measured
starting from T0 s in the 8-1000 keV band
is 14 +/- 3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."