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

GCN Circular 13961

GRB 121108A, Swift-BAT refined analysis
2012-11-09T14:24:40Z (12 years ago)
Tilan Ukwatta at MSU <>
W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), G. Sato (ISAS), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent
telemetry downlink, we report further analysis of BAT
GRB 121108A (trigger #537921) (Ukwatta, et al., GCN Circ. 13952).
The BAT ground-calculated position is RA, Dec = 83.216, 54.520 deg
which is
   RA(J2000)  =  05h 32m 51.9s
   Dec(J2000) = +54d 31' 11.2"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 90%.

BAT light curve shows two multi-peak episodes. First one starts
at the trigger time and lasts for about 50 seconds and the
second weak episode starts around T+130 seconds and lasts for about
40 seconds. T90 (15-350 keV) is 89 +- 48 sec (estimated error
including systematics).

The time-averaged spectrum from T-0.15 to T+137.98 sec is best fit
by a simple power-law model.  The power law index of the time-averaged
spectrum is 2.28 +- 0.20.  The fluence in the 15-150 keV band is
9.6 +- 1.2 x 10^-07 erg/cm2. The 1-sec peak photon flux measured
from T+43.18 sec in the 15-150 keV band is 1.6 +- 0.2 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
Looking for U.S. government information and services? Visit