"The evolution of GMCs and stellar clusters in spiral galaxies"
Abstract: I will present results from numerical simulations investigating the evolution of GMCs and stellar clusters. We find that GMCs have lifetimes ranging from ~5 to 30 Myr, according to a definition whereby at least half the mass of the chosen cloud must be present. However the formation and disruption of the GMCs takes place over 10’s Myr timescales. The precursors to spiral arm GMCs appear to be giant filaments which traverse the inter-arm regions, of which only the peaks may be detected with CO. These filaments enter the spiral arms and combine with more diffuse gas to form GMCs. The evolution of stellar clusters mimics that of their natal GMCs, so shorter lived clusters occur in short-lived GMCs and vice versa. We compare age distributions of the simulated and observed clusters, and find that the simulated clusters disperse slightly faster than real clusters.