In-orbit performance of the XMM-Newton X-ray telescopes: images and spectra

The performance of the three X-ray telescopes on-board of XMM-Newton is evaluated addressing imaging characteristics and effective collecting area. The agreement with ground calibration data is excellent. The analysis of images and spectra of cosmic X-ray sources, emphazising supernova and supernova remnants, prooves that the telescopes are even better than originally required.