GCN Circular 7677
Subject
GRB 080503, Swift-BAT lag and time-resolved spectral analysis
Date
2008-05-04T18:39:40Z (16 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
T. Ukwatta (GWU), M. Stamatikos (GSFC/ORAU), T. Sakamoto (GSFC/UMBC),
J. Norris (U. of Denver), S. D. Barthelmy (GSFC)
(for the Swift-BAT team):
For GRB 080503 (Trigger 310785, GCNs 7665 & 7673),
the spectral lag analysis of the data from T-1 sec to T+1 sec
(the initial spike), yields a lag of -13 +/- 9 msec for the
15-25 to 50-100 keV bands using lightcurve binnings of 4, 8 and 16 msec.
For the on-going emission (T+10 to T+220 sec), the signal is too weak
and lacking sufficient structure to yield a significant lag measurement.
Expanding on the total-burst spectral analysis in GCN 7673,
we have divided the burst into an initial phase (T+0.0 to T+0.7 sec)
and the extended phase (T+10 to T+170 sec). The simple power law fits are:
Phase PLI Norm(@50keV) Chi2/DoF
Initial 1.59 +/-0.28 (8.15 +- 1.5)E-3 69/59
Extended 1.91 +/-0.12 (1.19 +- 0.08)E-3 52/59
The units of Normalization are ph/cm2/s/keV.
This lag value plus the spectral results puts this burst
in the short hard burst category.