Black holes in AGN: recent results on IC 4329a and NGC 4945

This paper briefly reviews the observations which provide the best evidence for the presence of black holes in active galaxies: kinematic studies usin g optical emission lines as well as the distribution of megamaser spots; X- ray variability; and the profile of the Fe K alpha X-ray emission line. It summarizes the current popular models for the radiative processes operating in radio-quiet AGN. Finally, it presents two recent X-ray observations of AGN, where (1) the shape of the Fe K line indicates a diversity of location s where such lines originate (based on the ASCA & RXTE data for IC 4329a an d NGC 5548), and (2) the rapid hard X-ray variability measured with the RXT E in the heavily absorbed Seyfert 2 NGC 4945 implies that the Thomson-thick absorber surrounding the nucleus (with tau similar or equal to 2.4) is unl ikely to subtend a large solid angle to the nucleus, meaning that it is not geometrically thick, but is confined to a rather thin, disk-like structure .