Impact of metallicity on the evolution of young star clusters
ABSTRACT We discuss the results of N−body simulations ofintermediate-massyoung star clusters(SCs) with three diﬀerent metallicities (Z= 0.01, 0.1 and 1 Z ⊙ ), including metallicity-dependent stellar evolution recipes and metallicity-dependent prescriptions for stellarwinds and remnant formation. The initial half-mass relaxation time of the simulatedyoung SCs (∼10 Myr) is comparable to the lifetime of massive stars. We show thatmass-loss by stellar winds inﬂuences the reversal of core collapse and the expansion ofthe half-mass radius. In particular, the post-collapse re-expansion of the core is weakerfor metal-poor SCs than for metal-rich SCs, because the former lose less mass (throughstellar winds) than the latter. As a consequence, the half-mass radius expands fasterin metal-poor SCs. The diﬀerence in the half-light radius between metal-poor SCs andmetal-rich SCs is (up to a factor of two) larger than the diﬀerence in the half-massradius.Key words: stars: binaries: general – stars: evolution – stars: mass-loss – galaxies:star clusters: general – methods: numerical – stars: kinematics and dynamics.