A new method to determine the thickness of non-edge-on disk galaxies
Department of Astronomy, Nanjing University, Nanjing 210093, PR China e-mail: [yhzhao;qhpeng;taohu]@nju.edu.cn
Accepted: 15 December 2005
Aims.We present a new method to determine the thickness of non-edge-on disk galaxies. This method allows us to investigate the mass-to-light ratio of the disk.
Methods.Our method is based on the comparison of observations and theory of the distribution of the vertical velocity dispersion, which is obtained from the solution of three dimensional Poisson equations and the galactic dynamical equation.
Results.As examples, the thickness and mass-to-light ratio of two disk galaxies, NGC 1566 and NGC 5247, which have been extensively studied by spectroscopy, have been calculated. The calculated results are consistent with observations and support the use of this method. However, due to the small sample size available, the results should be confirmed on other samples of galaxies.
Key words: Galaxy: disk / Galaxy: kinematics and dynamics / Galaxy: structure / galaxies: individual: NGC 1566 / galaxies: individual: NGC 5247
© ESO, 2006