[vsnet-grb-info 8287] GRB 090815: Fermi GBM detection
GCN Circulars
gcncirc at capella.gsfc.nasa.gov
Sat Aug 15 22:11:34 JST 2009
TITLE: GCN CIRCULAR
NUMBER: 9812
SUBJECT: GRB 090815: Fermi GBM detection
DATE: 09/08/15 13:11:29 GMT
FROM: Andreas von Kienlin at MPE <azk at mpe.mpg.de>
A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team:
"At 07:12:12.45 UT on 15 August 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090815 (trigger 272013134 / 090815300).
The on-ground calculated location, using the GBM trigger
data, is RA = 41.7, DEC = -2.0 (J2000 degrees, equivalent
to 02h 47m, -02d 00'), with an uncertainty of 7.6 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.
The GBM light curve shows two broad pulses with a duration
(T90) of about 200 s (8-1000 keV). The time-averaged spectrum
from T0-5.120 s to T0+24.576 s is well fit by a simple power
law function with index -1.5 +/- 0.1 (chi squared 261 for 241 d.o.f.).
The event fluence (8-1000 keV) in this time interval is
(3.4 +/- 0.3)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+ 3.072 s in the 8-1000 keV band
is 1.9 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
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