We have compared the 2001 XMM-Newton spectra of the stellar mass black hole binary XTE J1650-500 and the active galaxy MCG–6-30-15 , focusing on the broad , excess emission features at \sim 4–7 keV displayed by both sources .
Such features are frequently observed in both low mass X-ray binaries and active galactic nuclei .
For the former case it is generally accepted that the excess arises due to iron emission , but there is some controversy over whether their width is partially enhanced by instrumental processes , and hence also over the intrinsic broadening mechanism .
Meanwhile , in the latter case , the origin of this feature is still subject to debate ; physically motivated reflection and absorption interpretations are both able to reproduce the observed spectra .
In this work we make use of the contemporaneous BeppoSAX data to demonstrate that the breadth of the excess observed in XTE J1650-500 is astrophysical rather than instrumental , and proceed to highlight the similarity of the excesses present in this source and MCG–6-30-15 .
Both optically thick accretion discs and optically thin coronae , which in combination naturally give rise to relativistically-broadened iron lines when the disc extends close to the black hole , are commonly observed in both class of object .
The simplest solution is that the broad emission features present arise from a common process , which we argue must be reflection from the inner regions of an accretion disc around a rapidly rotating black hole ; for XTE J1650-500 we find spin constraints of 0.84 \leq a ^ { * } \leq 0.98 at the 90 per cent confidence level .
Other interpretations proposed for AGN add potentially unnecessary complexities to the theoretical framework of accretion in strong gravity .