Calibration Access and Data Handbook

Procedure

The described procedure returns the one-dimensional response distribution in PI channels, based on an input energy.

CanonicalRedist retrieves a set of parameters from the EPIC-pn redistribution CCF and passes these to the CALPNALGO_resp routine. This routine then calculates the response, in each PI channel bin, for an input photon energy, an event pattern selection and a RAW-Y (row) position on the CCD.

The redistribution parameters have been calibrated as a function of:

Observing mode

- The shape of the response has a significant dependence on the observational mode.

Event grade

- The instrumental resolution is most sharp when the electrons generated by an incoming photon are collected in a single pixel. It degrades progressively as events are spread over multiple pixels. A separate calibration is available for single-pixel events (pattern=0) and double-pixel events (patterns 1-4).

chipY

- The act of transferring charge across the pixels to the readout introduces an extra spread in the detector response. This works such that pixels close to the camera centre have poorer resolution than those towards the edge of the field-of-view. The calibration is based on the chip-Y coordinate.