TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5602 SUBJECT: GRB 060923B: Swift XRT Refined Analysis DATE: 06/09/24 00:24:19 GMT FROM: Milvia Capalbi at ISAC/ASDC M. Capalbi, M. Perri , M.L. Conciatore (ASDC), D.N. Burrows (PSU) and M. Stamatikos (NASA/ORAU) report on behalf of the Swift XRT team: We have analysed the first 2 orbits of XRT data from GRB 060923B (Stamatikos et al., GCN Circ. 5590) with a total exposure of 2.1ks in photon counting mode. The refined position is: RA(J2000) = 15h 52m 46.83s, Dec(J2000) = -30d 54m 11.9s with an uncertainty of 6 arcsec (90% containment). This position is 0.7 arcsec from the one calculated from early downlinked data (Stamatikos et al., GCN Circ. 5590). The 0.3-10.0 keV X-ray light curve can be fit with a single power-law with a slope of -0.7+/-0.1. A power-law fit to the X-ray spectrum from T + 125s to T + 365s gives a photon index of 1.7+/-0.5, fixing the hydrogen column density to the galactic value in the direction of the burst (8.8e20cm**-2). The 0.3-10.0 keV observed flux is 8.5e-12 ergs cm**-2 s**-1, which corresponds to an unabsorbed flux of 8.9e-12 ergs cm**-2 s**-1. If the burst continues decaying at the current rate we estimate an XRT count rate of 0.014 counts/s at T + 24hr, which corresponds to an observed 0.3-10.keV flux of 5.6e-13 ergs cm**-2 s**-1. This circular is an official product of the Swift XRT Team.