[vsnet-grb-info 18431] GRB 160829A: Fermi-LAT detection of a short GRB

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19879
SUBJECT: GRB 160829A: Fermi-LAT detection of a short GRB
DATE:    16/08/29 17:28:47 GMT
FROM:    Judith Racusin at GSFC  <judith.racusin at nasa.gov>

J. L. Racusin (NASA/GSFC), G. Vianello (Stanford), D. Kocevski (NASA/GSFC), 
E. Bissaldi (Politecnico & INFN Bari), and R. Desiante (INFN Torino) 
report on behalf of the Fermi-LAT team:
At 08:01:37 on August 29, 2016 Fermi-LAT detected high-energy emission from 
GRB 160829A, which was also detected by Fermi-GBM (trigger 494150501/160829334). 
The best LAT on-ground location is found to be
RA, Dec = 201.7, -56.77 (degrees, J2000)
with an error radius of 0.12 deg (90% containment, statistical error only). 
This was 11 deg from the LAT boresight at the time of the trigger.
The data from the Fermi-LAT show an increase in the event rate within 10 deg of the 
GBM location after the GBM trigger that is spatially and temporally correlated with 
the GBM emission. 
The highest-energy photon is a 9.5 GeV event which is observed ~2 seconds after the 
GBM trigger, and the GRB is otherwise relatively faint, with only 3 photons (>100 MeV)
with a >90% probability of being associated with the burst. 
A Swift ToO has been requested for this burst.
The Fermi-LAT point of contact for this burst is Judith Racusin (judith.racusin at nasa.gov).
The Fermi-LAT is a pair conversion telescope designed to cover the energy band 
from 20 MeV to greater than 300 GeV.  It is the product of an international 
collaboration between NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.