Abstract
To investigate the nature and the evolution of optically faint, luminous infrared starburst galaxies, a deep survey of two 44'×44' fields in the Lockman Hole region was conducted using ISOPHOT camera on ISO at 95 and 175 mu m (Kawara et al. 1998). We present the preliminary results from our multi-wavelength investigations of the identified sources in the Lockman Hole ROSAT/XMM deep field (de Ruiter et al. 1997, Hasinger et al. 2001). One or more radio sources are found at the source position in more than 80% of cases, and spectroscopic redshifts of about 50% of the sources have been obtained so far.
