Galactic models with massive coronae. III. Giant elliptical galaxy M 87.

A model of the giant elliptical galaxy M 87 is calculated using the algorithm described in Paper I. The method is based on the assumption that 1) the galaxy is in a steady state, 2) galactic populations are physically homogeneous, and 3) equidensity surfaces of the galactic populations are similar concentric ellipsoids or can be represented as sums of such ellipsoids. All available observational data on surface photometry from the U to K bands, stellar velocity dispersions, distribution of globular clusters and their velocity dispersion, as well as the distribution of X-rays have been collected. These data were used to decompose the galaxy into a central nucleus, a metal-rich bulge, a metal-poor halo and a massive dark corona. The structural parameters, colour indices and mass-to-light ratios of these populations are derived. The gravitational potential and mass distribution functions of M 87 and subsystems are found. Problems concerning the possible presence of a massive black hole in the centre of the galaxy and the mass of the metal- poor halo are discussed. The mass-to-luminosity ratio of optically visible parts of the galaxy is M/LB = 4.9+/-2.0 M_sun_/L_sun_, the ratio of the total mass to the visible mass M_T_/M_vis_ = 130 inside the radius of 90'.