[vsnet-grb-info 14620] GRB 140305A, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15934
SUBJECT: GRB 140305A, Swift-BAT refined analysis
DATE:    14/03/05 23:43:35 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC),
C. B. Markwardt (GSFC), A. Maselli (INAF-IASFPA), D. M. Palmer (LANL),
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-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 140305A (trigger #590446)
(Maselli, et al., GCN Circ. 15929).  The BAT ground-calculated position is
RA, Dec = 344.497, 15.448 deg which is 
  RA(J2000)  =  22h 57m 59.4s 
  Dec(J2000) = +15d 26' 53.3" 
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 48%.

The mask-weighted light curve shows a FRED-like peak starting at T-1 sec, 
peaking at T sec, and ending at T+20 sec.  
T90 (15-350 keV) is 13.7 +- 1.8 sec (estimated error including systematics).

The time-averaged spectrum from T-1.1 to T+16.3 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.32 +- 0.92, 
and Epeak of 70 +- 32 keV (chi squared 45.13 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 4.7 +- 0.7 x 10^-7 erg/cm2
and the 1-sec peak flux measured from T+0.18 sec in the 15-150 keV band is
1.0 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.49 +- 0.17 (chi squared 51.59 for 57 d.o.f.).  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/590446/BA/