[vsnet-grb-info 7500] GRB 090326: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9059
SUBJECT: GRB 090326: Fermi GBM detection
DATE:    09/03/31 04:24:09 GMT
FROM:    Michael S. Briggs at UAH and MSFC  <michael.briggs at nasa.gov>

Michael S. Briggs (UAH)
reports on behalf of the Fermi GBM Team:

"At 15:10:49.48 UT on 26 March 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090326 (trigger 259773051 / 090326633).

The on-ground calculated location, using the GBM trigger
data, is RA = 259.6, DEC = -11.6 (J2000 degrees,
equivalent to 17 h 18 m, -11 d 36'), with an uncertainty
of 1.8 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 103 degrees.

The GBM light curve shows two peaks
with a duration (T90) of about 11.2 s (8-1000 keV).
The time-averaged spectrum from T0-3.072 s to T0+10.240 s is
well fit by a power law function with an exponential
high energy cutoff.  The power law index is -0.86 +/- 0.22 and
the cutoff energy, parameterized as Epeak, is 75. +/- 8. keV.
The fluence in this time interval is (8.6 +/- 1.8)E-07 erg/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."