ISO continuum observations of quasars at

Abstract

Eight luminous quasars with $-30 < M_{B} < -27$ at $z = 1.4{-}3.7$ have been observed in the mid- and far-infrared using ISO. All the quasars have been detected in the mid-infrared bands of ISOCAM, while no far-infrared detections have been made with ISOPHOT. SEDs (Spectral Energy Distributions) from the UV to far-infrared have been obtained while supplementing ISO observations with photometry in the optical and near-infrared made from the ground within 17 months. The SEDs are compared with the MED (Mean spectral Energy Distributions) of low-redshift quasars with $-27 < M_{B} < -22$. It is shown that our far-infrared observations were limited by confusion noise due to crowded sources