GRB 140305A

A. Maselli (INAF-IASFPA), S. D. Barthelmy (GSFC),
P. A. Evans (U Leicester), S. T. Holland (STScI), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), K. L. Page (U Leicester),
P. Romano (INAF-IASFPA) and M. H. Siegel (PSU) report on behalf of the
Swift Team:

At 15:00:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140305A (trigger=590446).  Swift did not slew to this burst
because of the Sun constraint. 
The BAT on-board calculated location is 
RA, Dec 344.533, +15.441, which is 
   RA(J2000)  =  22h 58m 08s
   Dec(J2000) = +15d 26' 29"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a cluster of peaks
with a total duration of about 25 sec.  The peak count rate
was ~1700 counts/sec (15-350 keV), at ~1 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 16:35 UT on 2014 April 25. There will thus be no XRT or
UVOT data for this trigger before this time. 

Burst Advocate for this burst is A. Maselli (maselli AT ifc.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

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
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 ).  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+0 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/

[GCN OPS NOTE(05mar14):  Per author's request, the peak time was changed
from "T" to "T+0".]