XMM-Newton calibration observations of the radio-loud quasar 3C273

We report preliminary results obtained from the XMM-Newton calibration observation of 3C273. During this observation, the source exhibited no significant flux or spectral variability. The source was in one of its lowest historical flux state (F2-10keV similar to 7 x 10(-11) erg cm(-2) s(-1)) and its 0.3-10 keV spectrum was complex. In particular, there is clear evidence for a break in the continuum (the spectrum being steeper below 1 keV) and, most remarkably, both the MOS and PN spectra exhibited a broad (sigma similar to 1+/-0.5 keV) FeK line, confirming recent ASCA results. These findings support therefore previous claims that a Seyfert-like nucleus is hiding in this X-ray bright radio-loud quasar. The data also highlight well the XMM-Newton capabilities, but also some outstanding calibration uncertainties, when observing very bright X-ray sources. A more detailed analysis and cross-calibration of MOS, PN and RGS are in progress to better quantify and establish the reality of these results.