[vsnet-grb-info 7970] GRB 090616: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9511
SUBJECT: GRB 090616: Fermi GBM detection
DATE:    09/06/17 08:59:09 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs at mpe.mpg.de>

Elisabetta Bissaldi (MPE) reports on behalf of the Fermi GBM Team:


"At 03:45:42.53 UT on 16 June 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090616 (trigger 266816744 / 090616157).
The on-ground calculated location, using the GBM trigger
data, is RA =  103.1, DEC = -3.7 (J2000 degrees,
equivalent to 06h 52m, -03d 42'), with an uncertainty
of 10.4 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 68 degrees.

The GBM light curve shows a single pulse
with a duration (T90) of about 2.7 s (8-1000 keV).
The time-averaged spectrum from T0-0.128 s to T0+0.512 s
is adequately fit by a simple power law function with
index -1.27 +/- 0.07 (chi squared 290 for 360 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(2.23 +/- 0.09)E-07 erg/cm^2. The 256-msec peak photon flux measured
starting from T0-0.128 s in the 8-1000 keV band
is 2.08 +/- 0.11 ph/s/cm^2.


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