[vsnet-grb-info 15128] GRB 140619B: Fermi-LAT Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16420
SUBJECT: GRB 140619B: Fermi-LAT Detection
DATE:    14/06/20 01:02:03 GMT
FROM:    Daniel Kocevski at SLAC  <dankocevski at gmail.com>

GRB 140619B: Fermi-LAT detection

D. Kocevski (NASA/GSFC), F. Longo (University and INFN Trieste), G. Vianello (Stanford University), V. Connaughton (University of Alabama, Huntsville), J. McEnery (NASA/GSFC) and E.Sonbas (Adiyaman Univ.) report on behalf of the Fermi-LAT team:

At UT 11:24:47 on June 19, 2014, Fermi-LAT detected high-energy emission from GRB 140619B, which was also detected by Fermi-GBM (trigger 424869883 / 140619475).  A preliminary analysis of GBM data characterizes this event as a short hard burst, with a T90 duration of ~0.5s (GCN 16419).

The best LAT on-ground location is found to be:

(RA, Dec) = 132.68, -9.66 (deg, J2000)

with an approximate error radius of 0.06 deg (90% containment, statistical error only).

This was 32 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 within ~3 degree of the GBM location after the GBM trigger that is spatially and temporally correlated with the GBM emission with high significance. More than 19 photons above 100 MeV and more than 5 photons above 1 GeV are observed within 5 seconds. The highest-energy photon is a 24 GeV event which is observed 0.61 seconds after the GBM trigger.  

The Fermi-LAT point of contact for this burst is Eda Sonbas edasonbas at yahoo.com.

A Swift ToO has been requested for this burst.

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.