[vsnet-grb-info 15129] GRB 140619B: Fermi-LAT detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16421
SUBJECT: GRB 140619B: Fermi-LAT detection
DATE:    14/06/20 01:02:23 GMT
FROM:    Valerie Connaughton at UAH/NSSTC  <valerie.connaughton at nasa.gov>

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 11:24:41 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 (Connaughton et al. 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 ~5 degrees of the GBM location after the GBM trigger time  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 <mailto:edasonbas at yahoo.com>.

A Swift ToO has been requested and accepted 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."