Heating of galactic discs with realistic vertical potentials

The heating of galactic discs through scattering by molecular clouds and spiral waves is investigated by solving the orbit-averaged Fokker-Planck equation by Monte Carlo simulation. The vertical potential in the disc is handled in two ways: (i) by using a fixed and realistic anharmonic potential, or (ii) by generating the potential self-consistently, assuming that the disc can be approximated as a one-dimensional self-gravitating layer. The shape of the velocity ellipsoid is found to be little changed from earlier work in which a fixed harmonic potential was used. Self-consistent simulations have been run of coeval and star-forming discs with and without accretion