[vsnet-grb-info 22662] GRB 190606A: Fermi-LAT detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24761
SUBJECT: GRB 190606A: Fermi-LAT detection
DATE:    19/06/06 15:06:23 GMT
FROM:    Elisabetta Bissaldi at INFN,Bari  <elisabetta.bissaldi at ba.infn.it>

E. Bissaldi (Politecnico & INFN Bari), M. Axelsson (KTH & Stockholm Univ.),
M. Arimoto (Kanazawa Univ.) and F. Longo (Univ & INFN Trieste)
report on behalf of the Fermi-LAT team:


"On June 6, 2019, Fermi-LAT detected high-energy emission
from GRB 190606A, which was also detected by Fermi-GBM
(trigger 581478912 / 190606080) and AGILE-MCAL
(Ursi et al., GCN #24759).

Due to the large angle with respect to the LAT boresight,
the positional error for this GRB is uncertain.
The best LAT on-ground location is found to be:

RA, Dec 76.54, -0.68 (degrees, J2000)

with an error radius of 3.0 deg (90% containment,
statistical error only).
This was 72 deg from the LAT boresight
at the time of the GBM trigger:
T0 = 01:55:07.78 UT.
  
The data from the Fermi-LAT show a significant increase
in the event rate after the GBM trigger that is spatially
correlated with the GBM emission with high significance.

The photon flux above 100 MeV in the time interval
T0 - T0+250 s after the GBM trigger is (4.3 +/- 1.9)E-05 ph/cm2/s.
The highest-energy photon in this interval is a 1.6 GeV event
observed at T0+154 s.
The estimated photon index above 100 MeV is 2.5 +/- 0.5.

The Fermi-LAT point of contact for this burst is
Elisabetta Bissaldi (elisabetta.bissaldi at ba.infn.it).


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."