2007A&A...461..917J

We present the results of the analysis of the hard band XMM-Newton spectra of the luminous, L_2–10keV∼3.4x10⁴⁵erg/s, radio-quiet quasar, E1821+643. Two emission features were observed in the 6-7keV rest frame band, confirming previous Chandra detection of these structures. We interpret these features as two single emission lines, one consistent with the neutral Fe Kα line at 6.4keV and the other most likely due to FeXXVI. If related to the quasar, the high-energy emission line should originate in highly ionised matter, i.e. the accretion disc or the clouds of the emission line regions. Alternatively, it may be related to the intergalactic medium of the rich galaxy cluster in which E1821+643 is embedded. A composite broad emission line in combination with an absorption line model, however, also fits the data well. We discuss the possible physical interpretations of the origin of these features.