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GCN Circular 10724

Swift-BAT refined analysis of trigger 421262
2010-05-06T20:59:14Z (14 years ago)
Scott Barthelmy at NASA/GSFC <>
T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+495 sec from the recent telemetry downlink,
we report further analysis of BAT trigger #421262
(Beardmore, et al., GCN Circ. 10722).  The BAT ground-calculated position is
RA, Dec = 280.341, -4.912 deg, which is 
   RA(J2000)  =  18h 41m 21.9s 
   Dec(J2000) = -04d 54' 43.7" 
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 69%.
The mask-weighted light curve shows a single spike starting at ~T-0.008 sec
and ending at ~T+0.020 sec.  T90 (15-350 keV) is 0.024 +- 0.008 sec
(estimated error including systematics).
The time-averaged spectrum from T-0.008 to T+0.020 sec is best fit by a
simple power-law model.  The power law index of the time-averaged spectrum is
1.87 +- 0.4.  The fluence in the 15-150 keV band is 1.4 +- 0.3 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.49 sec in the 15-150 keV band
is 0.21 +- 0.04 ph/cm2/sec.  All the quoted errors are at the 90% confidence
The results of the batgrbproduct analysis are available at

We reiterate our statement in the first circular that this trigger
may be an SGR event from the known AXP source.

[GCN OPS NOTE(07may10): Per author's request, the fluence value
was corrected to from 5e-7 to 1.4e-8. We apologize for the inconvenience.]
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