Tran Quang Dan 1, Lutz Dieter 1, Sturm Eckhard 1, Rigopoulou Dimitra 1, Taniguchi Yoshiaki , Ward Martin , Sanders David , Moorwood Alan , Scoville Nick , Soifer Tom , Hines Dean , & Gérin Maryvonne
1 Max Planck Institut fur Extraterrestrische Physik, Giessenbachstrasse Garching Germany
We present the first results of the ISOCAM-CVF ULIRG survey (Lutz et al.). This survey covers a luminosity range from 1012.3 to 1012.8solar luminosity and extends the sample observed with PHOT-S and SWS (Genzel et al. 1997, Lutz et. al (in prep.)) to high luminosity galaxies. These former surveys showed that it is possible to connect the line to continuum ratio of the 7.7 micron band to the relative importance of the AGN part of a ULIRG to its starburst part. The ISOCAM-CVF survey then allow us to exhibit the trend of the L/C ratio with respect to the luminosity and thus to test the different evolutionnary scenarios. But, as the ISOCAM-CVF mode is more sensitive and has a better spectral coverage than PHOT-S, we can determine the strength of the 6.2 and 11.3 microns bands of the observed ULIRG. It is then possible to compare bands ratio of this ULIRG to ratio observed in template sources, and then to have a better understanding of the physicals conditions of the ISM in this sources. Furthermore, the better sensitivity around 10 microns of ISOCAM allow one to study the role of the silicate extinction in this sources.