XMM-Newton Science Analysis System


rmfgen (rmfgen-2.8.7) [xmmsas_20230412_1735-21.0.0]

Spectrum-response channel range matching

Fitting packages such as XSPEC do not allow the channel range of the spectrum and that defined in the RMF to differ. XSPEC assumes the spectral range to correspond to the legal range of the CHANNEL column, ie the attributes TLMIN1 and TLMAX1.

If the channel range of the spectrum and that of the reponse data obtained from the CAL are found to differ, rmfgen raises a warning and performs one of the following corrective actions:

• If the spectrum contains channels that are outside the response range, rmfgen will pad out the response (prior to the grouping described above) to fit the spectral range.

• If the channel range of the spectrum is a subset of the response range, rmfgen will truncate the response data to match the channel range.

Note that the only accepted value for TLMIN is zero (which is the same as the lower bound for the CAL data, ensuring that the spectral channel range can only be a subset or superset of the response channel range, and not overlapping).