XMM-Newton view of the double-peaked Fe Kα complex in E1821+643

¹ Dipartimento di Fisica di l'Universita Roma Tre, via della Vasca Navale 84, 00146 Rome, Italy e-mail: ejimenez@fis.uniroma3.it
² XMM-Newton Science Operations Centre, ESAC, ESA, Apartado 50727, 28080 Madrid, Spain
³ Osservatorio Astronomico di Roma (INAF), via Frascati 33, 00040 Monteporzio Catone, Italy

Received: 8 May 2006
Accepted: 22 August 2006

Abstract

We present the results of the analysis of the hard band XMM-Newton  spectra of the luminous,  erg/s, radio-quiet quasar, E 1821+643. Two emission features were observed in the 6–7 keV 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 6.4 keV 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 E 1821+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.