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GCN Circular 13384

Subject
GRB 120624B, Swift-BAT refined analysis
Date
2012-06-25T20:53:53Z (12 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.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), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
A. M. Parsons (GSFC), G. Sato (ISAS), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-60 to T+243 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 120624B (trigger #525068)
(Vianello, et al., GCN Circ. 13379; Barthelmy, et al., GCN Circ. 13381).  
The BAT ground-calculated position is RA, Dec = 170.886, 8.933 deg which is 

   RA(J2000)  =  11h 23m 32.6s 
   Dec(J2000) = +08d 56' 00.4" 

with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 86%.
 
The mask-weighted light curve shows multiple overlapping episodes starting 
from T-25 sec.  There are two main episodes going from T-10 to T+70 sec with a
peak around T+35 sec, and the second episode starts T+120 sec and appears to 
end around T+200 sec, with peaks at T+140 sec and T+170 sec.  But the data ends 
due to observing constraint and slewing to a pre-planned target.  T90 (15-350 keV) 
is greater than 192 sec due to the end of the mask-weighted light curve when 
the source location left the field of view.  

The time-averaged spectrum from T-15.1 to T+192.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.17 +- 0.03.  The fluence in the 15-150 keV band is 2.83 +- 0.04 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+138.06 sec in the 15-150 keV band
is 5.5 +- 0.2 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/525068/BA/
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