[vsnet-grb-info 15306] GRB 140716A BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16598
SUBJECT: GRB 140716A BAT refined analysis
DATE:    14/07/16 22:05:17 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings at nasa.gov>

J. R. Cummings, S. D. Barthelmy (GSFC), W. H. Baumgartner (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), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU/NASA/GSFC), J. Tueller (GSFC), T. N. Ukwatta (GWU)
on behalf of the Swift-BAT team:

We report further analysis of the ground-detected GRB 140716A (Cummings,
GCN # 16596) using 20 seconds of photon-event data that cover the first and third
peaks, and BAT survey data covering the entire burst.

The best BAT position remains RA, Dec 108.133 -60.150, which is

RA (J2000)    07h 12m 31.9s
Dec (J2000)  -60d 08' 59"

with an estimated 90% confidence radius of 1.5 arcmin.  The source was 3% coded
in BAT.

The burst had three peaks with similar maximum flux, the first 2 seconds long, the
second 4 seconds long at T+90, and the third about 8 seconds long at T+100.  The
emission was undetectable between the first and second peaks, while there was a
slight overlap between peaks 2 and 3.  The total T90 was about 104 +- 2 seconds.
At T+112 seconds, Swift executed a preplanned slew, putting the source completely
out of the BAT coded field of view, but we can say that there was no bright
emission above about 50 keV after this time.

The average spectrum from 15 to 150 keV is best fit by a simple power law function
with a photon index of 1.61 +- 0.33.  The total fluence was
(5.9 +- 1.2) x 10^-6 ergs/cm^2.  The peak 1-second flux was
5.2 +- 1.5 photons/sec/cm^2 from T+0.2 to T+1.2 seconds.  All the quoted errors are
at the 90% confidence level.

A Swift TOO request has been approved and is being executed with the target number
20390.