TITLE:   GCN CIRCULAR
NUMBER:  11921
SUBJECT: GRB 110411A, Swift-BAT refined analysis
DATE:    11/04/12 00:05:34 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):

Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110411A (trigger #451165)
(Grupe, et al., GCN Circ. 11918).  The BAT ground-calculated position is
RA, Dec = 291.427, 67.706 deg which is
     RA(J2000)  =  19h 25m 42.5s
     Dec(J2000) = +67d 42' 21.0"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 71%.

The burst had multiple peaks with gradual rise and fall. The two largest peaks
were centered around T+5 sec and T+60 sec.  T90 (15-350 keV) is 80.3 +- 5.2 sec
(estimated error including systematics).

The time-averaged spectrum from T-11.9 to T+86.3 sec is best fit by a power
law with an exponential cutoff.  This fit gives a photon index 1.51 +- 0.31,
and Epeak of 41.0 +- 8.1 keV (chi squared 49.70 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 3.3 +- 0.2 x 10^-06 erg/cm2
and the 1-sec peak flux measured from T+4.73 sec in the 15-150 keV band is
1.3 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.05 +- 0.07 (chi squared 59.73 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/451165/BA/