Structure of the Spiral Galaxy NGC 300

In 1963, Toomre built up classes of mass models for the highly flattened galaxies which have free parameters n, an and Cn. In order to keep the universal dimension, we adopt parameters bn(Cn2 = an2n+2*bn2/(n-1)!) instead of Cn. Series of the normalized Toomre's mass models (G = Vmax = Rmax = 1, n =1 to 7) are derived and the normalized parameters an and bn to an(=an*rmax) and bn(=bn*Vmax/rmax), we can get the generalization of Toomre's mass model.