Simultaneous XMM-Newton and BeppoSAX observation of the Seyfert I galaxy IC 4329A

We report on a simultaneous XMM-Newton and BeppoSAX observation of the Seyf ert 1 galaxy IC 4329A performed in 2001 January. Above 1 keV, EPIC spectra show a narrow Fe K emission line at 6.42(-0.03)(+0.04) keV with an equivale nt width of 43 +/- 1 eV. An absorption edge is detected at 7.1 +/- 0.4 keV in the source rest frame that has not been reported before. The energy of t hese features is consistent with reflection of the primary X-ray continuum by a optically thick material containing iron in low states of ionization. The narrow Fe K feature suggests that the reflection arises relatively far from a putative central black hole. Spectral fitting of simultaneous XMM-Ne wton and BeppoSAX data over the 0.3-130 keV energy range shows that the pri mary continuum is well described by a cut-off power law with a photon index of 1.93 +/- 0.03 and a folding energy of 260 +/- 130 keV. The high energy tail >10 keV constrains the reflection fraction close to unity. Fitting ove r the overall spectral range indicates that the Fe abundance within the coo l reflecting material is not significantly different from the cosmic value. The extrapolation of the primary power law continuum to energies <1 keV in dicates the presence of absorption edges produced by neutral and ionized ox ygen. The optical depth of the O I edge at 0.54 keV constrains the intrinsi c absorption by neutral material to an hydrogen column density of = (33 +/- 3) x 10(20) cm(-2) along the line of sight to IC 4329A nucleus. The energy of the edge at 0.854 +/- 0.009 keV is consistent with absorption by O VIII . A third edge at 0.660 +/- 0.008 keV is likely related to absorption by O VI and N VII. The simultaneous presence of O VI and O VIII edges without si gnificant O VII absorption indicates that the warm absorber originates from at least two zones.