[vsnet-grb-info 7330] GRB 090129: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8897
SUBJECT: GRB 090129: Fermi GBM detection
DATE:    09/02/09 17:17:37 GMT
FROM:    Sylvain Guiriec at UAH  <sylvain.guiriec at lpta.in2p3.fr>

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

"At 21:07:15.42 UT on 29 January 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090129 (trigger 254956037 / 090129880) which was
also detected by the SWIFT-BAT.
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight is 22 degrees.

The GBM light curve consists of a single peak with a FRED shape starting at
~T0-0.3s with a duration (T90) of about 17.2s (8-1000 keV).
The time-averaged spectrum from T0-0.3s to T0+15.1s is well fitted by a
Band function with Epeak = 123.2 +/- 44.8 keV, alpha = -1.39 +/- 0.13,
and beta = -1.98 +/- 0.14 (chi squared 373 for 374 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(5.6 +/- 0.7)E-06 erg/cm^2.
The 1-sec peak photon flux measured starting from T0+0.8 s in the
8-1000 keV band is 8.0 +/- 0.1 ph/s/cm^2.

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