Calibration of the first XMM flight mirror module: I. Image quality

The high throughput x-ray spectroscopy mission (XMM) is a 'Cornerstone' Project in the ESA long-term Program for Space Science. The satellite observatory uses three grazing incidence mirror modules coupled to reflection grating spectrometers and x-ray CCD cameras. Each XMM mirror module consists of 58 Wolter I mirrors which are nested in a coaxial and confocal configuration. The calibration of the mirror system includes the development of a representative numerical model and its validation against extensive calibration test performed on ground at the CSL and PANTER test facilities. The present paper describes the calibration of the x-ray image quality of the first XMM flight mirror module.