Notes. We group all observations by time into six epochs and fit the data in each epoch simultaneously. Swift observations within the same epoch are combined and treated as a single observation. We also give the radius of the circular region that we use for the source+background spectral extraction in each observation (R_circ). We followed Evans et al. (2009) in determining the radius of this source+background region to extract for Swift observations. In our spectral analysis, the energy band we use is given in the last column.