[vsnet-grb-info 7283] GRB 090126B: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8853
SUBJECT: GRB 090126B: Fermi GBM detection
DATE:    09/01/26 16:31:43 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 05:26:22.23 UT on 26 January 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090126B (trigger 254640384  / 090126227 ).

The on-ground calculated location, using the GBM trigger 
data, is RA = 190.5, DEC = 33.2  (J2000 degrees, 
equivalent to 19h 42m, 33d 12'), with an uncertainty 
of 4.4 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 18 degrees.

The GBM light curve consists of a single peak
with a duration (T90) of about 10.8 s (8-1000 keV). 
The time-averaged spectrum from T0-4.608 s to T0+5.632 s is 
best fit by a power law function with an exponential
high energy cutoff.  The power law index is -0.99 +/- 0.18 and
the cutoff energy, parameterized as Epeak, is 47.5 +/- 3.4 keV
(chi squared 404.17 for 360 d.o.f.).

The event fluence (8-1000 keV) in this time interval is 
(1.25 +/- 0.24)E-06 erg/cm^2. The 1-sec peak photon flux measured 
starting from T0-0.512 s in the 8-1000 keV band 
is 4.9 +/- 1.3 ph/s/cm^2.

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