Merging, resulting from galaxy interaction and collision, is one essential scenario to interpret the distinct evolutionary stages of galaxy formation. However AGNs are believed to play an essential role towards the final stages of this scenario, in particular to clear the galaxy from a large excess of dust. Selecting galaxies with both 70μm and X-ray detection will help to understand the relation between star formation and AGN. We are taking advantage of the extensive multi-wavelength coverage of the Cosmic Evolution Survey (COSMOS) field to dissect the AGN influence on infrared luminous objects. We demonstrate that enhanced star formation is more probably responsible for additional obscuration of the central AGN than the dust torus, in agreement with current galaxy formation theory. Furthermore, we demonstrate that the presence of an AGN does not increase the galaxy dust temperature significantly.