1 Introduction

This article is meant as technical reference for questions related to the point spread functions of the instruments of the ROSAT satellite. The latter are fully and in a unified form presented. So, the point spread function densities, the cumulative distributions in both ROSAT observation modes are given. Spread measures derived from the point spread functions such as FWHM and medians are introduced. The underlying assumptions for the point spread function models are laid open. Model limitations are mentioned.

Section 2 introduces the instruments of the ROSAT satellite. Section 3 explains general features of the point spread functions. In three subsections the point spread functions of the two different X-ray detectors and the extreme UV detector are presented. In a fourth subsection, the ROSAT survey point spread function is considered. At the expense of a slight redundance, the exposition is complete at the detector level. All material belonging to a detector is presented in the respective subsection. The effect of the physical attitude jitter or imprecise attitude data on the point spread function is treated in Sect. 4. The conclusions are collected in the final Sect. 5. An Appendix, Sect. 6, contains point spread function related aids provided by the data analysis system EXSAS.