Unveiling the dominant gas heating mechanism in local LIRGs and ULIRGs

Joint Institute for VLBI in Europe (JIVE), 7990 AA Dwingeloo, The NetherlandsE-mail:polatidis@jive.nlWe show preliminary results from a sample of Luminous and Ultra-Luminous Infrared Galaxies(LIRGs and ULIRGs, respectively) in the local universe, obtained from observations using theVery Large Array (VLA), the Multi-Element Radio Link Interferometer Network (MERLIN),and the European VLBI Network (EVN). The main goal of our high-resolution, high-sensitivityradio observations is to unveil the dominant gas heating mechanism in the central regions oflocal (U)LIRGs. The main tracer of recent star-formation in (U)LIRGs is the explosion of core-collapse supernovae (CCSNe), which are the endproducts of the explosion of massive stars andyieldbrightradioevents. Therefore,ourobservationswill notonlyallowus to answer thequestionof the dominant heating mechanism in (U)LIRGs, but will yield also the CCSN rate and the star-formation rate (SFR) for the galaxies of the sample.The 9th European VLBI Network Symposium on The role of VLBI in the Golden Age for Radio Astronomyand EVN Users MeetingSeptember 23-26, 2008Bologna, Italy