Title : The Next Generation of Numerical Modeling in Mergers - Constraining the Star Formation

Spectacular images of colliding galaxies like the "Antennae", taken with the Hubble Space Telescope, have revealed that a burst of star/cluster formation occurs whenever gas-rich galaxies interact. The ages and locations of these clusters reveal the interaction history and provide crucial clues to the process of star formation in galaxies. We propose to carry out state-of-theart numerical simulations to model six nearby galaxy mergers (Arp 256, NGC 7469, NGC 4038/39, NGC 520, NGC 2623, NGC 3256), hence increasing the number with this level of sophistication by a factor of 3. These simulations provide specific predictions for the age and spatial distributions of young star clusters. The comparison between these simulation results and the observations will allow us to answer a number of fundamental questions including: 1) is shock-induced or density-dependent star formation the dominant mechanism; 2) are the demographics (i.e. mass and age distributions) of the clusters in different mergers similar, i.e. "universal", or very different; and 3) will it be necessary to include other mechanisms, e.g., locally triggered star formation, in the models to better match the observations? ======================================================================