[vsnet-grb-info 24293] Possible HAWC-detected GRB 191210A: Fermi-LAT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26392
SUBJECT: Possible HAWC-detected GRB 191210A: Fermi-LAT Upper Limits
DATE:    19/12/11 21:41:53 GMT
FROM:    Nicola Omodei at Stanford U.  <nicola.omodei at slac.stanford.edu>

N. Omodei (Stanford U.), S. Cutini (INFN Perugia), and F.Longo (University and INFN, Trieste) 

report on behalf of the Fermi-LAT Collaboration:

Fermi-LAT has performed follow-up observations of the possible HAWC-detected burst GRB 191210A: https://gcn.gsfc.nasa.gov/notices_amon_hawc/9066_1171.amon

At the time of the HAWC trigger (T0), the location of the candidate transient was outside the LAT field of view, at an inclination angle of 145 degrees.

The region of Interest entered in LAT field of view at about T0+2.5 ks and exited again at 4.5 ks.

During this time window we performed a search for a transient counterpart, and no significant new sources are found. 

The flux upper bounds in the 100 MeV - 10 GeV (90% CL), assuming a E^-2 power law spectrum, are:

Energy flux < 8.76e-10 [erg/cm2/s]
Photon flux < 1.18e-06 [ph./cm2/s]

We also searched for late time emission (until T0+100 ks seconds) and no significant excess is found. 

The Fermi-LAT point of contact for this event is:
Nicola Omodei (nicola.omodei at 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.