filter intensity

After you have made a light curve, you can enter intensity selections, given as a range of acceptable values. The scale for intensity is read from the plot given in PLOT CURVE. The task converts this intensity selection to a set of GTI's, which are passed to the next EXTRACT run.

So

xsel > filter intensity .1-1.5

will PASS only those bins with an intensity between .1 and 1.5.