Wednesday, July 28, 2010

A note on the pileup model

It is easy to misinterpret the "PSF fraction" parameter in the pileup model. A natural reading is to suppose that this means the fraction of the PSF which is included in the source extraction region. This is not correct. For the pileup model to work well the extraction region should be large enough to include essentially all the PSF. The "PSF fraction" parameter is actually the fraction of counts detected which should not be included in the pileup calculation. The manual will be modified to make this clearer. My thanks to Pat Broos for pointing out this potential confusion.

Tuesday, July 27, 2010

cplinear model

I have added Pat Broos' cplinear model to the additional models page. This is a non-physical model developed within the AE package to handle background in the low count case.

Monday, July 12, 2010

Yaqoob & Murphy toroidal reprocessor model

I've added a link to the additional models page for the Yaqoob & Murphy model for X-ray obscuration and reflection by a toroidal reprocessor, valid in the Compton-thick regime.

Thursday, July 08, 2010