[vsnet-grb-info 15343] GRB 140729A: Fermi-LAT detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16633
SUBJECT: GRB 140729A: Fermi-LAT detection
DATE:    14/07/29 09:10:16 GMT
FROM:    Makoto Arimoto at Tokyo Inst of Tech  <arimoto at hp.phys.titech.ac.jp>

M. Arimoto (Tokyo Tech) and E. Bissaldi (University & INFN Trieste)
report on behalf of the Fermi-LAT team:


At UT 00:36:59 on July 29th, 2014, Fermi-LAT detected
high-energy emission from GRB 140729A, which was also
detected by Fermi-GBM (trigger 140729026 / 428287016).

The best LAT on-ground location is found to be

(RA, Dec) = 193.95, +15.35 (deg, J2000)

with an approximate error radius of 0.34 deg (90% containment,
statistical error only).
This was 26.2 deg from the LAT boresight at the time of the trigger.


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 100 photons above 100 MeV and 13 photons
above 1 GeV are observed within 550 s, before the
spacecraft entered the SAA.
The GRB does not come back into the Fermi-LAT FoV for more than 6000s.
The highest-energy photon is a 1.3  GeV event
which is observed 44 s after the GBM trigger.


A Swift ToO has been requested for this burst.


The Fermi-LAT point of contact for this burst is
Makoto Arimoto (arimoto at hp.phys.titech.ac.jp).

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.