Abstract

SIMONNEAU, E.  and  PRADA, F.. Structural properties of spherical galaxies: a semi-analytical approach. Rev. mex. astron. astrofis [online]. 2004, vol.40, n.1, pp.69-79. ISSN 0185-1101.

Since the distribution of light measured along any galactocentric radius of an elliptical galaxy has the same functional form exp [-R^1/n](Sérsic profile) for almost all galaxies, and since this profile is the Abel integral of the luminous density, it looks worth-while to seek the way to derive the latter from the former. We propose in this paper a "discrete ordinate" method, which yields, for any value of n>1, an explicit expression for the luminous density, ρ_L(r), that can be evaluated numerically to any required degree of precision. Once we have obtained such an expresion for the spatial density, ρ_L(r), we can compute straightforwardly the mass distribution, M(r), the potential, Φ(r), and the velocity dispersions, σ²_s(r), in space and on the observational plane, σ²_ρ(R).

Keywords : Galaxies [Elliptical]; Galaxies [Kinematics and dynamics]; Galaxies [Structure].

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