TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5622 SUBJECT: GRB 060926: Swift XRT refined analysis DATE: 06/09/27 00:24:50 GMT FROM: Matteo Perri at ISAC/ASDC M. Perri, M. Capalbi, M.L. Conciatore (ASDC), D.N. Burrows (PSU) and S.T. Holland (GSFC/USRA) report on behalf of the Swift XRT team: We have analysed the first three orbits of Swift XRT data on the BAT GRB 060926 (Holland, et al., GCN Circ. 5612). A 4.7 ks Photon Counting mode image provides a refined XRT position: RA(J2000) = 17h 35m 43.93s Dec(J2000) = +13d 02' 18.4" with an uncertainty of 5.9" (90% containment). This is 29.8" away from the center of the BAT refined position (Cummings et al., GCN Circ. 5621). This localization lies 11.3" from the XRT position and 4.0" from the UVOT position quoted in GCN Circ. 5612 (Holland, et al.). The 0.3-10 keV X-ray light curve during the first orbit shows a flare at T+430s. Between second and third orbit a power-law decline with a temporal index of -1.6+/-0.4 is observed. The X-ray spectrum covering the time period from T+67s to T+878s is well fit by an absorbed power-law with a photon index of 2.1(+/-0.3) and column density of (2.2+/-0.9)e21 cm**-2. We note the Galactic column density in the direction of the source is 7.3e20 cm**-2. Assuming the X-ray emission continues to decline at the same rate, we predict a 0.3-10 keV XRT count rate of ~1e-3 count/s at T+24hr, which corresponds to an observed 0.3-10 keV flux of ~4e-14 erg/cm**2/s. This circular is an official product of the Swift XRT Team.