Normalization (top) and absorption column density (n_H; bottom; y axis is log scale) parameters from our spectral fitting of the XMM-Newton observations as functions of phase. Circles (0.6 keV component) and filled squares (2.0 keV component) represent the two different model components. In the case of observation 2272, we split the observation at phase 0.624 as well as fitting the whole observation (Sect. 3.1). Diamonds (open = 0.6 keV, closed = 2.0 keV) represent the two data sets derived from this split. Points are plotted in phase at the midpoint of each observation. Dotted vertical lines represent phases 0.0, 0.5, and 1.0. All data have been wrapped in phase so that more than one complete cycle is shown.