How Many Active Galaxies and QSOs Will Future Space Missions Detect?

Averaged spectral energy distributions (SEDs) of active and starburstgalaxies from the 12 micron sample in the Local Universe and Quasars, from anoptically selected sample at a mean redshift =0.7, are built fromoptical/near-IR/far-IR (IRAS & ISO) photometric observations. These SEDs arethen used to predict at various redshifts the number of Seyfert type 1 and type2, starburst, normal galaxies, and quasars, that will be detected by futureSpace Missions dedicated to far-infrared and submillimeter astronomy, likeSIRTF and Herschel. These predictions are then compared with the expectedcapabilities and detection limits of future deep far-IR surveys. Possible waysto identify AGN candidates on far-IR colour-colour plots for follow-upobservations are then explored.Comment: accepted in Ap