[vsnet-grb-info 14498] GRB 140209A, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15812
SUBJECT: GRB 140209A, Swift-BAT refined analysis
DATE:    14/02/09 19:27:41 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm at nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),  W. H. Baumgartner (GSFC/UMBC),
S. B. Cenko (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC),
T. Sakamoto (AGU), 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+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 140209A (trigger #586071)
(Cenko, et al., GCN Circ. 15808).  The BAT ground-calculated position is
RA, Dec = 81.328, 32.488 deg which is
    RA(J2000)  =  05h 25m 18.7s
    Dec(J2000) = +32d 29' 17.3"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 38%.

The mask-weighted light curve shows an initial weak pulse from T+0 to T+0.5 sec, 
followed by the main pulse from T+1.5 to T+3.5 sec, with a FRED-like profile 
with some superimposed structure.  This is followed by some low-level
extended emission out to ~T+50 sec.  T90 (15-350 keV) is 21.3 +- 8.0 sec 
(estimated error including systematics).

The time-averaged spectrum from T+0.15 to T+29.22 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.44 +- 0.06.  The fluence in the 15-150 keV band is 4.1 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.69 sec in the 15-150 keV band
is 38.1 +- 1.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

It is possible that this burst falls in the category of short burst with 
extended emission.
A lag analysis is underway that will be reported in a subsequent circular.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/586071/BA/