Deep surveys with ISOCAM Original Research Article

After the extensive IRAS observations of the local universe (z < 0.2) and the discovery of the far-infrared extragalactic background radiation with COBE, the improved sensitivity and resolution of ISOCAM, the camera on-board the Infrared Space Observatory (ISO), has allowed us to explore the infrared universe up to high redshifts (z < 1.5). In particular, the extragalactic deep ISOCAM surveys allowed us to extend the IRAS counts by 5 orders of magnitude, to evaluate the global star formation up to z = 1.5 and to resolve a large part of the cosmic infrared background. Optical follow-up observations of the ISOCAM galaxies, which are now in progress, will allow a better understanding of the nature of the infrared emission in distant galaxies.