[vsnet-grb-info 8040] GRB 090626: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9579
SUBJECT: GRB 090626: Fermi GBM detection
DATE:    09/06/26 11:26:22 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 04:32:08.88  UT on 26 June 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090626 (trigger 267683530  / 090626189).
The on-ground calculated location, using the GBM trigger data,
is RA = 169.3, DEC = -36.1 (J2000 degrees, equivalent to 11h 17m, -36d 06'),

with a statistical uncertainty of less than 1 degree 
(radius, 1-sigma containment) and an additional systematic error which 
is currently estimated to be 2 to 3 degrees. 
The angle from the Fermi LAT boresight is 15 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve consists of four main peaks with a duration (T90) 
of about 70 s (8-1000 keV). The time-averaged spectrum from 
T0-0.256 s to T0+69.377 s is best fit by a Band function with 
Epeak = 175 +/- 12 keV, alpha = -1.29 +/- 0.02, and 
beta = -1.98 +/- 0.02 (chi squared 578 for 477 d.o.f.).

The event fluence (8-1000 keV) in this time interval is 
(3.5 +/- 0.1)E-05 erg/cm^2. The 1.024-sec peak photon flux measured 
starting from T0+1.024 s in the 8-1000 keV band 
is 17.9 +/- 1.4 ph/s/cm^2.

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