GCN Circular 4764
Subject
GRB060206: Swift XRT observations of an unbroken powerlaw decay
Date
2006-02-15T23:34:08Z (19 years ago)
From
David Morris at PSU/Swift-XRT <morris@astro.psu.edu>
D. C. Morris (PSU), C. Pagani (PSU), D. N. Burrows (PSU), J. A. Kennea
(PSU) and K.Page (U. Leicester) report on behalf of the Swift XRT team:
The Swift XRT has continued to monitor the light curve of GRB060206 with
data taken as late as T+8 days. Our complete X-ray dataset from T+5ks to
T+700ks remains consistent with a single unbroken powerlaw decay with
alpha=1.35+/-0.15. We note that there is apparent variability, both
positive and negative, on the timescale of days in the X-ray lightcurve
somewhat larger than is implied by simple counting statistics. Our data
are not consistent, however, with a break to a slope of -2.2 at T+27
hours and thus we cannot confirm the presence of the jet break reported
in I-band observations by LaCluyze et al. (GCN 4750).
The XRT data remain consistent with the prediction by Palmer et al (GCN
4597) of a jet break at 8.6 or 10.4 days (743ks or 899ks). The XRT
countrate during the last observation, on February 14th, was 2e-3 cts/s,
equivalent to a flux of approximately 1.5e-13 ergs/cm2/s. Observations
are ongoing.
The XRT lightcurve can be viewed at
http://www.swift.psu.edu/images/GRB060206.jpg
This circular is an official product of the Swift XRT Team.