New method for determining the thickness of non-edge-on disk galaxies

In this paper we report a new method for determining the thickness of the non-edge-on disk galaxies. Our method is based on the observation comparing with the theoretical researches of the distribution of the vertical velocity dispersion, which is obtained from the solutions of three dimensional Poisson's equation and the galactic dynamical equation. This method also allows us to investigate the mass-to-light ratio of the disk. As examples, the thickness and mass-to-light ratio of two disk galaxies, NGC 1566 and NGC 5247, which have been extensively studied in spectroscopy, have been calculated and the results are presented.