[vsnet-grb-info 15331] GRB 140723A: Fermi-LAT detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16623
SUBJECT: GRB 140723A: Fermi-LAT detection
DATE:    14/07/23 14:19:02 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi at uibk.ac.at>

E. Bissaldi (University & INFN Trieste), R. Desiante (Udine
University & INFN Trieste), M. Axelsson (Stockholm University),
D. Kocevski (NASA/GSFC) and F. Piron (LUPM)
report on behalf of the Fermi-LAT team:



At UT 01:36:30.73 on July 23rd, 2014, Fermi-LAT detected
high-energy emission from GRB 140723A, which was also
detected by Fermi-GBM (trigger427772193 / 140723067).

The best LAT on-ground location is found to be

(RA, Dec) = 210.63, -3.73 (deg, J2000)

with an approximate error radius of 0.35 deg (90% containment,
statistical error only). This was 55 deg from the LAT
boresight at the time of the trigger.

An image with the 68% and 90% containment regions
have been posted at:

http://slac.stanford.edu/~bissaldi/GRB140723A_LAT_tsmap.png

The data from the Fermi-LAT show a significant increase
in the event rate that is spatially and temporally
correlated with the GBM emission with high significance.
More than 170 photons above 100 MeV and 3 photons
above 1 GeV are observed within 1200 s, before the spacecraft
entered the SAA. The source entered the FoV again around 5800 s
after the trigger. The highest-energy photon is a
1.8 GeV event, which is observed 163 s after the GBM trigger.

A Swift ToO has been requested for this burst.

The Fermi-LAT point of contact for this burst
is Elisabetta Bissaldi (Elisabetta.Bissaldi at ts.infn.it).



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.