MIDINFRARED SPECTROSCOPY OF THE HYPERLUMINOUS INFRARED GALAXY IRAS P09104+4109

We present mid-infrared spectroscopy of the hyperluminous infrared gal axy IRAS 09104+4109 based on observations with ISOCAM CVF. We have det ected the emission peak around 8 mu m as well as the absorption featur e around 10 mu m possibly due to silicate, providing evidence for a du sty torus around the central engine. Comparing the observational resul ts with the dusty torus model studied by Pier & Krolik (1992), we show that the most mid infrared emission comes from a compact (a few pc in radius) dusty torus although the excess far infrared emission suggest s the presence of an extended dusty torus with radius of similar to 10 0 pc.