[vsnet-grb-info 6885] Fermi Detection of GRB 081102

GCN Circulars gcncirc at capella.gsfc.nasa.gov
Wed Nov 5 01:32:35 JST 2008


TITLE:   GCN CIRCULAR
NUMBER:  8476
SUBJECT: Fermi Detection of GRB 081102
DATE:    08/11/04 16:32:24 GMT
FROM:    Chryssa Kouveliotou at MSFC  <chryssa.kouveliotou at nasa.gov>

C. Kouveliotou (NASA/MSFC) and M.S. Briggs (UAHuntsville) report on
behalf of the Fermi GBM Team:

At 17:44:21.6 UT on 02 November 2008, the Fermi GBM triggered and
located an event (trigger 247340662 / 081102739) which was also seen by
SWIFT (Ukwata et al. 2008, GCN 8462). The GBM on-ground location is
consistent with the Swift position; the GBM trigger time is 17.4 s
earlier than the Swift trigger. 

The GBM light curve shows a multiple peak event (three and possibly four
peaks) with T90= 88 s (50-300 keV). The time-averaged spectrum from
T0-2.048 s to T0+46.01 s is best fit by a exponentially cutoff power law
model with Epeak = 88.7 +/- 8.3 keV, and index 0.0 +/- 0.3 (chi squared
278 for 238 d.o.f.). The event fluence (50-300 keV) in this time
interval is (2.1 +/- 0.05)E-06 erg/cm^2. A Band function fit the
spectrum equally well (chi squared 276 for 237 d.o.f.) with Epeak=72 +/-
13, alpha = 0.44 +/- 0.58 and beta = -2.36 +/- 0.32. 

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


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