[vsnet-grb-info 16124] GRB 150204A BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17406
SUBJECT: GRB 150204A BAT refined analysis
DATE:    15/02/04 19:53:28 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings at nasa.gov>

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

We report further analysis of GRB 150204A.  The best BAT position is the same
as reported earlier (Cummings, GCN # 17404), RA, Dec 160.241, -64.043, which is:

RA (J2000)   10h 40m 57.8s
Dec (J2000) -64d 02' 34"

with an estimated 90% uncertainty radius of 1.5 arcmin.  The source was 77% coded
at the time of the burst.

The burst was a single symmetric cusp.  T90 was 12 +- 2 seconds.

A simple powerlaw function is the best fit to the BAT spectrum.  The photon index
is 1.62 +- 0.10.  The fluence from 15 to 150 keV in 13 seconds was
(8.0 +- 0.4) x 10^-7 ergs/cm^2.  The 1-second peak flux in this energy range was
1.85 +- 0.12 photons/cm^2.  All uncertainties are 90% confidence.

A Swift TOO has been approved.