GCN Circular 5147
Subject
GRB 060210: Jet Break in the XRT light curve
Date
2006-05-18T00:59:16Z (18 years ago)
From
Xinyu Dai at Ohio State U <xinyu@astronomy.ohio-state.edu>
X. Dai and K. Z. Stanek (Ohio State Univ.)
We analyzed the Swift-XRT light curve of GRB 060210 (Beardmore et al. 2006
GCN 4724). We added new data points to the X-ray light curve presented in
Stanek et al. 2006 (astro-ph/0602495 v1) up to 1.e6 sec after
the BAT trigger. We detected a smooth jet break (t_j = 7.9^{+2.2}_{-1.6}
hr, observed) with the extended XRT light curve.
We fitted both a single power-law and a broken power-law model to the XRT
light curve from 3.e3 sec to 1.e6 sec after the BAT trigger. For the
single power-law model we found alpha=1.09 and chi^2(dof) = 292.3(69).
For the broken power-law model we found alpha1 = 0.7, alpha2 = 1.4, t_j =
7.9 hr, and chi^2(dof) = 64.8(67). We note that the power-law decay index
for the X-ray light curve before the jet break (alpha1 ~ 0.7) is not
consistent with the optical index (alpha_o ~ 1.3, Stanek et al. 2006
astro-ph/0602495). The XRT light curve for GRB 060210 is at
http://www.astronomy.ohio-state.edu/~xinyu/grb/060210.jpg
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