The soft and hard X-ray emission of 3C 273 from 1996 to 2004 with BeppoSAX and XMM-Newton Original Research Article

We present the results of a long monitoring of the quasar 3C 273 with BeppoSAX (1996–2001) and XMM-Newton (2000–2004). Our dataset is composed of nine BeppoSAX and 15 XMM observations for a total exposure time of 855 ks (∼492 ks for BeppoSAX and ∼363 ks for XMM). In the soft X-ray domain, we investigate the 2–10 keV continuum with MECS and PN and the presence of an Fe line with MECS. The hard X-ray emission of 3C 273 is analyzed using PDS (15–220 keV) on board BeppoSAX. Two particular flux states are observed in our dataset with a flare of non-thermal emission from the jet in January 1997, whereas the X-ray flux reaches its lowest value in June 2000 and in particular in June 2004. We confirm the detection of an Fe line in one observation performed with BeppoSAX in July 1996. In addition, we report two new detection with MECS of a relatively broad Fe line in June 1998 (also detected by ASCA) and in June 2001. Presence or lack of correlation between different spectral parameters allow us to distinguish the influence of the two emission processes (non-thermal + thermal) on the observed X-ray emission of 3C 273.