No CrossRef data available.
Published online by Cambridge University Press: 14 August 2015
The dynamical evolution of the solar neighbourhood is described by an accretion model in which the gas accretion rate decays exponentially with time. Stars form at a rate proportional to the local gas volume density and their velocity dispersion is increased after birth by star-cloud collisions. The present mass density distribution of stars and of gas perpendicular to the galactic plane (Oort 1965) and the observed increase of stellar velocity dispersion with age (Mayor 1974; Mayor and Martinet 1977) are reproduced for an e-folding time of 3 × 109 y of the gas accretion rate and a characteristic star formation time scale of 2.8 × 109 y.