In this section we briefly compare the properties of the PRF wings discussed in §5.2 and the off-axis PRF discussed in §6 to MARX+SAOSAC models. The modeled and measured data were analyzed in the same way and plotted in Figure , showing the 70% and 90% EER at three energies (3.5 keV, 5.2 keV, 6.4 keV) and at several off-axis angles. (At the time of these simulations, finite source size models were unavailable. However, we should be insensitive to finite source size effects at these off-axis angles.)
Several trends are seen in Figure between EER and off-axis location at all energies. First, EER(90%) increases faster with radius than the EER(70%) (slopes and errors are given in Figure ). Second, the slopes derived from the MARX+SAOSAC model agree fairly well with the XRCF data. Third, although the slopes agree, the models appear to be tighter than the XRCF data by ~10%. The slope differences between EER(70%) and EER(90%) are produced by mirror scattering. However, we do not understand the systematically smaller model spot size, although we can exclude pixelization on these scales.
All of the analysis products are available online at http://asc.harvard.edu/cal/Links/Acis/acis/Cal_prods/psf/psf.html
