Evolution of multicomponent stellar systems

Conditions of consistency for multicomponent stellar systems

Under a common potential, a finite mixture of ellipsoidal velocity distributions satisfying the Boltzmann collisionless equation provides a set of integrability conditions that may constrain the population kinematics. They are referred to as conditions of consistency and were discussed in a previous paper on mixtures of axisymmetric populations. As a corollary, these conditions are now extended...

Conditions of consistency for multicomponent axisymmetric stellar systems ⋆

Solving the Boltzmann collisionless equation under the axisymmetric hypothesis introduces serious limitations on describing the kinematics of a single stellar system according to the local Galactic observables. Instead of relaxing the hypothesis of axisymmetry, one alternative is to assume a mixture model. For a finite mixture of ellipsoidal velocity distributions, the coexistence of several st...

Spectrophotometric Evolution of Old Stellar Systems

Noise-driven evolution in stellar systems: Theory

We present a theory for describing the evolution of a galaxy caused by stochastic events such as weak mergers, transient spiral structure, orbiting blobs, etc. This noise excites large-scale patterns that drives the evolution of the galactic density profile. In dark-matter haloes, the repeated stochastic perturbations preferentially ring the lowest-order modes of the halo with only a very weak ...

Evolution of the Binary Fraction in Dense Stellar Systems

Using our recently improved Monte Carlo evolution code, we study the evolution of the binary fraction in globular clusters. In agreement with previous N -body simulations, we find generally that the hard binary fraction in the core tends to increase with time over a range of initial cluster central densities for initial binary fractions . 90%. The dominant processes driving the evolution of the...