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GCN Circular 12873

Subject

GRB 120118B, Swift-BAT refined analysis

Date

2012-01-19T14:48:38Z (12 years ago)

From

Hans Krimm at NASA-GSFC <hans.krimm@nasa.gov>

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), O. M. Littlejohns (U Leicester),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):

Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 120118B (trigger #512003)
(Littlejohns, et al., GCN Circ. 12852Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 124.862, -7.178 deg which is
     RA(J2000)  =  08h 19m 26.9s
     Dec(J2000) = -07d 10' 39.5"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 40%.

The mask-weighted light curve shows a single smooth FRED peak lasting from T-5
sec to T+25 sec.  T90 (15-350 keV) is 23.26 +- 4.02 sec (estimated error
including systematics).

The time-averaged spectrum from T-1.92 to T+30.51 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.08 +- 0.11.  The fluence in the 15-150 keV band is 1.8 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+6.69 sec in the 15-150 keV band
is 2.2 +- 0.3 ph/cm2/sec.  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/512003/BA/