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Session 20 - QSOs.
Oral session, Monday, January 13
Over the past 10 years studies of the spectral energy distributions of quasars have become possible and our understanding of the energy generation mechanisms at work has greatly increased. However a key area in which little advance has been made is the far-infrared (IR) where data exists only for the lowest redshift and reddest quasars and over a limited range in wavelength.
With ISO we are able, for the first time, to study the far-IR emission of a representative sample of quasars and over a wider energy range. Our program is obtaining photometry with ISOPHOT in eight broad bands between 5 and 200 m \mu for \sim95 quasars and active galaxies having a wide variety of properties. Our sample includes subsets which are X-ray, optically and IR selected, high and low redshift. Our initial aim is to delineate the far-IR continuum in order to determine the peak wavelength and long wavelength turnover, measure the luminosity and to address the fundamental question of the relative importance of thermal and non-thermal emission in the different types of quasars. We will present preliminary results including our first detection of a high redshift (z>4) quasar.
Program listing for Monday