Calibration Access and Data Handbook

Generation from Ground Calibration Data

During the ground calibration campaign no absolute photometric measurements were made at CSL. Therefore the CCF component was initially filled based on simulated data by SCISIM. A detailed description can be found in XMM-PS-TN-33 and only a short summary is given here.

OM count rates of different spectral types in different passbands were simulated with OSIM. The OM count rates are converted into OM magnitudes applying an zero point correction of 18.5 mag. The expected standard magnitudes of the various spectral types are taken from Zombeck.
The pre-launch colour transformation coefficients and the associated errors are calculated using the methode described by Harris et al. (PASP 1981, 93 507). Harris' recommendation is followed and the colour transformation is defined as quadratic function of the colour terms. The equations are solved by a multilinear regression.