[vsnet-grb-info 7954] GRB 090606: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9497
SUBJECT: GRB 090606: Fermi GBM detection
DATE:    09/06/08 15:17:29 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs at mpe.mpg.de>

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


"At 11:18:08.00 UT on 06 June 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090606 (trigger 265979890 / 090606471).
The on-ground calculated location, using the GBM trigger
data, is RA =  146.9, DEC = -70.5  (J2000 degrees,
equivalent to 09h 48m, -70d 30'), with an uncertainty
of 5.6 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 128 degrees.

The GBM light curve shows a long, weak pulse
with a duration (T90) of about 60 s (8-1000 keV).
The time-averaged spectrum from T0-5.1 s to T0+12.3 s
is adequately fit by a simple power law function with
index -1.63 +/- 0.09 (chi squared 243 for 237 d.o.f.).
The event fluence (8-1000 keV) in this time interval is
(3.19 +/- 0.16)E-06 erg/cm^2. The 1-sec peak photon flux
measured starting from T0+8 s in the 8-1000 keV band
is 2.41 +/- 0.17 ph/s/cm^2.


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