I present a general family of dynamical models with simple analytical potential-density pairs suited to modelling galactic bulges and nuclei with double power-law radial density profiles and an optional central black hole. Analytical expressions for the potential and velocity dispersion of these models are given for the spherical case. Many previously known analytical spherical models, including the recent γ/η-models by Dehnen and Tremaine et al., are special cases of this family. The family also forms a complete set for constructing general galaxy models or solving Poisson's equation in the non-spherical case. In particular, a generalized Clutton-Brock and Hernquist-Ostriker orthogonal basis set is given.

We apply standard disk formation theory with adiabatic contraction within cuspy halo models predicted by the standard LCDM cosmology. The resulting models score remarkably well when confronted with the broad range of observational data available for the Milky Way and M31 galaxies, giving a Milky Way virial mass of 1-2x10^12Msun and concentration C=12-17. We consider two types of models, in which: (A) baryons conserve angular momentum and (B) some of the angular momentum of the baryons is transferred to the dark matter. Type-A models produce good agreement with observed rotation curves and obey constraints in the solar neighborhood, but may have too much dark matter in the center to allow a fast rotating bar. The type-B models with angular momentum transport have a slightly more massive disk and less dark matter in the central part, allowing a fast rotating bar to persist. Both classes of models probably have sufficient baryonic mass in the central 3.5kpc to reproduce recent observational values of the optical depth to microlensing events towards the Galactic center. All models require that about 1/2 of all baryons expected inside the virial radius must not be in the disk or bulge. We investigate whether the range of virial masses allowed by our dynamical models is compatible with constraints from the galaxy luminosity function, and find a range of parameter space that is allowed by this constraint. We conclude that rotation curves and dynamical properties of ``normal'' high surface brightness spiral galaxies appear to be consistent with standard LCDM.Comment: 26 pages, 11 figures, submited to Ap

The past growth of the central black hole (BH) might have enhanced the density of cold dark matter halo particles at the galactic center. We compute this effect in realistic growth models of the present $\left(2\mathrm{}-3\right)\times {10}^6{M}_{\odot }$ BH from a low-mass seed BH, with special attention to dynamical modeling in a realistic galaxy environment with merger and orbital decay of a seed BH formed generally outside the exact center of the halo. An intriguing “very-dense spike” of dark matter has been claimed in models of Gondolo and Silk with a density high enough to contradict with experimental upper bounds of neutralino annihilation radiation. This “spike” disappears completely or is greatly weakened when we include important dynamical processes neglected in their idealized or restrictive picture with cold particles surrounding an at-the-center zero-seed adiabatically growing BH. For the seed BH to spiral in and settle to the center within a Hubble time by dynamical friction, the seed mass must be at least a significant fraction of the present BH. Any subsequent at-the-center growth of the BH and steepening of the central Keplerian potential well can squeeze the halo density distribution only mildly, whether the squeezing happens adiabatically or instantaneously.

The evolution of globular clusters due to two-body relaxation results in an outward flow of energy and at some stage all clusters need a central ener