GCN Circular 5010
V. Mangano (INAF-IASFPA), G. Tagliaferri (INAF-OAB), D. N. Burrows (PSU) report on behalf of the Swift XRT Team: We have analyzed the first orbit data of GRB060417 (Mangano et al 2006, GCN 5006). The XRT data set consists of 88 s exposure in Windowed Timing (WT) mode followed by 843 s exposure in Photon Counting (PC) mode. The refined position of the source is RA (2000) = 08h 17m 04.4s Dec (2000) = +62d 40' 18.3" with an uncertainty of 3.4 arcsec (90% confinement). This position is only 1 arcsec from the onboard detected position (Mangano et al 2006, GCN 5006). The 0.2-10 keV X-ray light curve shows an initial very fast decay with slope -4.3 +/- 0.2, a break at 247 +/- 12 s from the trigger and a final decay slope of -1.7 +/- 0.13. The WT and PC spectra were fitted separately with an absorbed power law model and showed photon indices of 2.9 +/- 0.1 and 2.37 +/- 0.14, respectively (90% confidence level). The WT spectrum, covering the time interval 138-227 s, accounts for the pre-break phase of the light curve. Both spectra show evidence of an absorption column at the level of (1.7 +/- 0.2) x 10^21 cm^-2 in excess with respect to the Galactic value of 4.3 x 10^20 cm^-2. The 0.2-10 keV unabsorbed fluxes of the two spectra are 1.3 x 10^-9 and 6.6 x 10^-11 erg cm^-2 s^-1, respectively. If decaying at the present rate the source will reach the flux level of 10^-14 erg cm^-2 s^-1 (corresponding to a count rate level of 1.5 x 10^-4 counts s^-1) after one day. This Circular is an official product of the Swift XRT Team.