Detection of iron features in the X-ray spectrum of the Seyfert I galaxy MCG-6-30-15

The spectral analysis of an extended (∼ 2 d) EXOSAT observation of the Seyfert I galaxy MCG-6-30-15 has revealed significant differences from the previous simple power-law description. In particular, evidence is found for both emission and absorption features from cold iron, indicating a large column density of material possibly located close to the central energy source. The underlying continuum spectrum is best described either by a two-power-law model or by a single power-law covered by a complex absorber. The relevance of these results to accretion in active galactic nuclei, in particular to disc and 'cold cloud' models, is briefly dicussed. (author)