GCN Circular 9172
G. Stratta and M. Perri (ASDC) report on behalf of the Swift-XRT Team: We have analysed the first 4 orbits of Swift-XRT data obtained from GRB 090419 (trigger 349592; Stratta, et al., GCN Circ. 9161), from T+128 s to T+271 s in Windowed Timing (WT) mode and from T+303 s to T+4.9 h in Photon Counting (PC) mode. The best position of the X-ray afterglow is the UVOT enhanced XRT position given in Osborne et al. (GCN Circ. 9164). The 0.3-10 keV X-ray light curve shows an initial flaring activity superimposed to a constant continuum at a level of ~5 counts/s up to ~520 s after the trigger that is consistent with being the X-ray tail of the BAT data (GCN Circ. 9167, Krimm et al.) during the prompt emission. Starting from 520 s up to 1200 s the count rate decays as a power law with alpha1=3.5+/-0.5 and from T+1200 to T+12 ks it features a flattening with index alpha2=1.1+/-0.2. If decaying at this rate, the afterglow will reach a count-rate of 1.3(0.6)E-3 counts/s at T+24(48)h. The average WT spectrum (corresponding to the initial flat decay phase) can be fitted by an absorbed power-law model (reduced chi square 1.0 with 18 degrees of freedom), with photon index 1.3+/-0.3, and equivalent hydrogen column density NH=(1.1+/-0.6)E22 cm-2 in excess with respect to the Galactic absorption value of 1.2E21 cm-2 (Kalberla et al. 2005). The average observed(unabsorbed) flux in the 0.3-10 keV band is 4.2(5.4)E-10 ergs cm-2 s-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00349510. This circular is an official product of the Swift-XRT team.