GCN Circular 4433
O. Godet, K. Page, A. Bearmore, J. Osborne (U. Leicester), D. N. Burrows (PSU), D. Grupe (PSU), H. Ziaeepour (UCL-MSSL), P. Boyd (GSFC-UMBC), L. Angelini (GSFC-JHU) report on behalf of the Swift XRT team: We analyzed the first 5 orbits of XRT data from GRB 060105. A 10.2ks photon counting (PC) mode image provides a refined XRT position: RA(J2000) = 19h 50m 00.6s Dec(J2000) = +46d 20' 58.3'' with an uncertainty of 3.2 arcsecs (90% containment). This position is 4.5 arcsecs away from the on-board XRT position quoted in Ziaeepour et al. (GCN 4429) and includes the latest XRT boresight correction. This position is 83 arcseconds from the BAT position (Ziaeepour et al., GCN 4429). The X-ray light curve can be fit with a double broken power-law with an initial decay slope of alpha1 = -1.16+/-0.14, a break at t1-T = 196 + 23/-29s, and a shallower post-break slope of alpha2 = -0.80+/-0.02, followed by another break at t2-T = 3306+/-200s and a steeper decay slope of alpha3 = -2.30+/-0.08. An absorbed power-law fit of the WT data (first orbit) from T+187s to T+1287s gave a photon index of 2.06+/-0.03 and an excess absorption value of (2.4+/-0.2)e21 cm**-2. The error bars are given at a 90% confidence level. The Galactic hydrogen column density in the direction of the burst is 1.8e21 cm**-2. The spectrum of the PC data (4 orbits) can be fit by an absorbed power-law with Gamma=2.17+/-0.16 and excess absorption of (2.8+/-0.8)e21 cm**-2. If the burst continues decaying at the current rate (alpha3) we estimate an XRT count rate of 0.0029 counts/s at T + 24hr, which corresponds to an observed 0.5-10.keV flux of 6.26e-13 ergs cm**-2 s**-1 and an unabsorbed flux of 9.82e-13 ergs cm**-2 s**-1.