Spectroscopic performance of detectors for Athena’s WFI: measurements and simulation

The Wide Field Imager of Athena is composed of two back side illuminated detector units using DEPFET sensors operated in rolling shutter readout mode. A large detector array featuring four sensors with 512 × 512 pixels each and a small detector that facilitates the high count rate capability of the WFI for the investigation of bright, point-like sources. First sensors from the flight production are now available. We present the spectral capability measured at different photon energies and asses the expected performance after years of operation in space using Monte Carlo simulations to combine all information gained by measurements.