... The calibration file GUI task calview supports the visualization of the four basic representations of the X-ray Point Spread Function (PSF) that are encoded in the Calibration Access Layer (CAL) as part of the SAS. ... It is both energy and off-axis angle dependent, but the same for each EPIC telescope . ... EXTENDED , corresponding to a King-profile model, energy, off-axis and telescope dependent [details can be found in the EPIC Calibration Status Document . ... Pages maintained by SAS librarian ....