Jeans modeling of axisymmetric galaxies with multiple stellar populations

We present the theoretical framework and the numerical setting of JASMINE2, a code designed to efficiently solve the Jeans equations for multi-component axisymmetric stellar systems. The models may include an arbitrary number of stellar distributions, a dark matter halo, and a central supermassive black hole; each stellar distribution is implicitly described by a two-integral distribution function, and the stellar components can have different structural (density profile, flattening, mass,scale-length), dynamical (rotation, velocity dispersion anisotropy), and population (age, metallicity, initial mass function, mass-to-light ratio) properties. In order to determine the ordered rotational velocity and the azimuthal velocity dispersion fields of each component, we introduce a decomposition that can be used when the commonly adopted Satoh decomposition cannot be applied. The numerical implementation of JASMINE2, and of the post-processing procedures (including projection), are optimised to fully exploit the scalings allowed by the Poisson and the Jeans equations. For illustrative purposes, we present three multi-component galaxy models with a central black hole and a dark matter halo; one of the models is also used to test JASMINE2 against available analytical solutions.