SCYON Abstract

Received on September 4 2006

Star clusters in the solar neighbourhood: how are they destroyed?

Authors H.J.G.L.M. Lamers and M. Gieles
Utrecht University
Accepted byAstronomy & Astrophysics


We predict the survival time of initially bound star clusters in the solar neighbourhood taking into account: (1) stellar evolution, (2) tidal stripping, (3) shocking by spiral arms and (4) encounters with giant molecular clouds. We find that the predicted dissolution time is tdis = 1.7 (Mi/104 Msun)0.67 Gyr for clusters in the mass range of 102 < Mi < 105 Msun, where Mi is the initial mass of the cluster. The resulting predicted shape of the logarithmic age distribution agrees very well with the empirical one, derived from a complete sample of clusters in the solar neighbourhood within 600 pc. The required scaling factor implies a star formation rate of 400 Msun/Myr within 600 pc from the Sun or a surface formation rate of 3.5x10-10 Msun/(yr pc2) for stars in bound clusters with an initial mass in the range of 102 to 3x104 Msun.