Skip to main content
New! October 18 GCN Classic Outage and Schema v4.2.0. See news and announcements

GCN Circular 7306

Subject
GRB 080212, Swift-BAT refined analysis
Date
2008-02-13T13:41:24Z (17 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
K. McLean (GSFC/UMD), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. Ukwatta (GWU), H. Ziaeepour (UCL-MSSL)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080212 (trigger #303105)
(Ziaeepour, et al., GCN Circ. 7296).  The BAT ground-calculated position is
RA, Dec = 231.145, -22.739 deg, which is 
   RA(J2000)  =  15h 24m 34.8s 
   Dec(J2000) = -22d 44' 19" 
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 35%.
 
The mask-weighted light curve shows the main burst acivity starting
at about T-60 sec, the main peak at ~T+5 sec, and ending at about T+110 sec.
There is a weak peak at T+250 to T+350 sec, which matches a flare
in in the XRT lighcurve peaking at about T+250 sec.
T90 (15-350 keV) is 123 +- 13 sec (estimated error including systematics).
 
The time-averaged spectrum from T-60.5 to T+75.7 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.31 +- 0.64, 
and Epeak of 67.6 +- 13.1 keV (chi squared 52.75 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 2.9 +- 0.3 x 10^-06 erg/cm2
and the 1-sec peak flux measured from T+3.75 sec in the 15-150 keV band is
1.2 +- 0.3 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.59 +- 0.12 (chi squared 68.06 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/303105/BA/
Looking for U.S. government information and services? Visit USA.gov