Calibration Access and Data Handbook

Purpose

Supply empirical corrections to the physical model of the RGS instrument reponse for two separate purposes:

• ensure independent agreement with of RGS models with known cosmic spectra
• improve consistency of simultaneous models of RGS and EPIC-pn spectra

The first of these is a purely RGS mechanism that forms part of the independent calibration of the effective area of the spectrometers and thus forms part of the effective area model delivered to observers by the SAS in RGS response matrices. The second mechanism, known as RGS-pn rectification, combines possible contributions of different origin including any deficiencies in the calibration of either instrument, data analysis procedures or spectral models and thus is not a part of the RGS calibration model. Rather, it provides a convenient mechanism for spectral analysis via RGS matrices modified for this particular purpose.