In the present paper we develop an algorithm allowing to calculate line-of-sight velocity dispersions in an axisymmetric galaxy outside of the galactic plane .
When constructing a self-consistent model , we take into account the galactic surface brightness distribution , stellar rotation curve and velocity dispersions .
We assume that the velocity dispersion ellipsoid is triaxial and lies under a certain angle with respect to the galactic plane .
This algorithm is applied to a Sa galaxy NGC 4594 = M 104 , for which there exist velocity dispersion measurements outside of the galactic major axis .
The mass distribution model is constructed in two stages .
In the first stage we construct a luminosity distribution model , where only galactic surface brightness distribution is taken into account .
Here we assume the galaxy to consist of the nucleus , the bulge , the disc and the stellar metal-poor halo and determine structure parameters of these components .
Thereafter , in the second stage we develop on the basis of the Jeans equations a detailed mass distribution model and calculate line-of-sight velocity dispersions and the stellar rotation curve .
Here a dark matter halo is added to visible components .
Calculated dispersions are compared with observations along different slit positions perpendicular and parallel to the galactic major axis .
In the best-fitting model velocity dispersion ellipsoids are radially elongated with \sigma _ { \theta } / \sigma _ { R } \simeq 0.9 - 0.4 , \sigma _ { z } / \sigma _ { R } \simeq 0.7 - 0.4 , and lie under the angles \leq 30 \degr with respect to the galactic equatorial plane .
Outside the galactic plane velocity dispersion behaviour is more sensitive to the dark matter density distribution and allows to estimate dark halo parameters .
For visible matter the total M / L _ { B } = 4.5 \pm 1.2 , M / L _ { R } = 3.1 \pm 0.7 .
The central density of the dark matter halo is \rho _ { DM } ( 0 ) = 0.033 ~ { } \mathrm { M _ { \sun } pc ^ { -3 } } .