GCN Circular 19158

G.Vianello (Stanford), M. Yassine (CNRS/IN2P3), E.Moretti (MPP Munich)

report on behalf of the Fermi-LAT team:

At 00:22:58.47 on March, 10, 2016 (T0) Fermi-LAT detected high-energy
emission from GRB 160310A, which was also detected by Fermi-GBM
(trigger 479262181 / 160310016).

The best LAT on-ground location is found to be

RA, Dec = 98.78, -7.11 (J2000)

with an error radius of 0.1 deg (90 % containment, statistical error only).

This was 62 deg from the LAT boresight at the time of the trigger, on
the edge of the field of view.

The data from the Fermi-LAT show a significant increase in the event
rate that is spatially and temporally correlated with the trigger with
high significance.

At the time of the trigger Fermi was in normal survey mode. The GRB
was observable by Fermi from T0 to ~T0 + 500 s, and then again from
~T0 + 5200 s and T0 + 7000 s. The highest-energy photon is a 30 GeV
event which is observed 5800 seconds after the GBM trigger.

A Swift ToO has been requested for this burst.

The Fermi-LAT point of contact for this burst is Giacomo Vianello
(giacomov@stanford.edu).

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.