Best-fit values of absorption column density (top), power-law slope (middle), and reflection strength (bottom panel). Class 1 objects are denoted by filled black circles and Class 2 objects by filled red squares. The open green diamonds indicate Class 3 sources and the open blue squares correspond to Class 4 objects. The open downward triangles in the top panel denote the 1σ upper limits of these values. The crosses in the middle panel denote the sources that were fitted with a fixed Γ value (see text for details).