[vsnet-grb-info 17603] GRB 160220A: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19038
SUBJECT: GRB 160220A: Swift-BAT refined analysis
DATE:    16/02/20 21:43:14 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm at nasa.gov>

H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160220A (trigger #674670)
(Lien, et al., GCN Circ. 19023).  The BAT ground-calculated position is
RA, Dec = 236.942, -18.539 deg which is
    RA(J2000)  =  15h 47m 46.2s
    Dec(J2000) = -18d 32' 20.6"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 26%.

The mask-weighted light curve shows a single peak of about 20 seconds total
duration starting at ~0 sec.  The spacecraft slewed away
from the burst location at ~T+220 sec due to a pre-planned maneuver.
T90 (15-350 keV) is 8.3 +- 1.2 sec (estimated error including systematics).

The time-averaged spectrum from T-0.02 to T+8.99 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.55 +- 0.24.  The fluence in the 15-150 keV band is 5.2 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.33 sec in the 15-150 keV band
is 1.0 +- 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/674670/BA/