GCN Circular 6040
Subject
GRB 070126, Swift-BAT refined analysis of a very faint burst
Date
2007-01-26T20:25:16Z (18 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
E. Fenimore (LANL), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMBC), 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), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), L. Vetere (PSU)
on behalf of the Swift-BAT team:
Using the data set from T-240 to T+500 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 070126 (trigger #257741)
(Veter, et al., GCN Circ. 6027). The BAT ground-calculated position
is RA, Dec = 33.579, -73.532 deg which is
RA(J2000) = 2h 14m 18.9s
Dec(J2000) = -73d 31' 54"
with an uncertainty of 2.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 99%.
The mask-weighted lightcurve shows a broad, weak, and soft bump from
T_zero to ~T+60 sec. T90 (15-350 keV) is 51 +- 5 sec (estimated error
including systematics).
The time-averaged spectrum from T+1.0 to T+56.0 is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.9 +- 0.5. The fluence in the 15-150 keV band is 1.6 +- 0.6 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+10.00 sec in the 15-150 keV
band is 0.2 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90%
confidence level. The flux of this burst is at the lower limit of the
BAT sensitivity.