GCN Circular 6326

M. Stamatikos (GSFC/ORAU), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J.
Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm
(GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), J. Tueller (GSFC) on behalf of
the Swift-BAT team:

Using the data set from T-239 to T+963 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 070419A
(trigger #276205)  (Stamatikos, et al., GCN Circ. 6302
Not found
 
 
).  The BAT
ground-calculated position
is RA, Dec = 182.755, 39.903 deg which is 
   RA(J2000) = 12h 11m 1.1s 
   Dec(J2000) = 39d 54' 11.0" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The
coding fraction was 1.

This position is ~1.5 arcmin from the position of the optical afterglow
candidate reported by Chornock et al. (GCN Circ 6304), which was further
confirmed by Cenko et al. (GCN Circ 6306). 
 
The mask-weighted light curve has a nearly symmetric, smooth profile,
although a tail of emission extends to about T+160 sec. The T90 (15-350 keV)
is ~116 +- 6 sec (estimated error including systematics).
 
The time-averaged spectrum, from T-35 to T+93, is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is 2.35
+- 0.25. The fluence in the 15-150 keV band is 5.6 +- 0.8 x 10^-7 erg/cm^2.
The 1-sec peak photon flux measured from T-1.12 sec in the 15-150 keV band
is 2.8 x 10^-2 ph/cm^2/sec.  All the quoted errors are at the 90% confidence
level.

Under a Lambda Cold Dark Matter cosmological model, with Ho ~ 65 km/Mpc/s,
Omega_M ~ 0.30, and Omega_Lambda ~ 0.70, the preliminary Keck absorption
redshift of 0.97, reported by Cenko et al. (GCN Circ 6322), when coupled to
the BAT fluence reported above, results in a preliminary isotropic energy
emission estimate of ~ 1.60 x 10^+51 ergs in the 15-150 keV observed (30-296
keV GRB rest frame) band pass.