Last modified: 24 October 2023

URL: https://cxc.cfa.harvard.edu/ciao/why/resperr.html

Systematic Errors on ACIS Responses

About Response Uncertainties

Instrument response uncertainties are generally ignored in astrophysical X-ray analysis, even though modern day X-ray telescopes will obtain data where the photon counting statistics is no the dominant source of errors. The tool mkacisrmf separates the RMF calculation process into two components: an "ideal" component which describes the CCD spectral response prior to the effects of CTI, and a spatially varying component which incorporates the changes in the response produced by CTI. The tool creates an RMF for an ACIS imaging observation (or zeroth-order grating) with the newest calibration available. Instructions on how to run this tool are given in the mkacisrmf help file.