Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 12097

Subject
GRB 110625A: Fermi LAT detection
Date
2011-06-26T19:52:11Z (13 years ago)
From
Thomas P.H. Tam at Nat.Tsing Hua U. <grbtom@gmail.com>
P.H.T. Tam and A.K.H. Kong (NTHU) report:

We report on the detection of >100 MeV gamma-ray emission from the direction
of GRB 110625A (Swift trigger
456073; Page et al., GCN #12088) using the Fermi Large Area Telescope
(LAT).

The GRB position was outside the LAT field of view (i.e., >75 deg with
respect to the LAT boresight) at the burst
onset (T0; 2011-06-25 UT 21:08:28; GCN #12088). However, prominent emission
up to several GeV was detected
from the GRB direction around T0+200s to T0+500s, during which the light
curve seems to resemble a double-peak
structure. Using the data obtained from the above period, we localized the
LAT emission at RA, DEC (J2000 deg) =
286.6, 6.9, with a statistical error of ~0.3 deg (68% CL), which is
compatible with the refined Swift/XRT position (Page
et al., GCN #12092). A preliminary spectral fit gives a photon spectral
index of around -3 at energies above 100
MeV.
Looking for U.S. government information and services? Visit USA.gov