Anisotropic stellar velocities: A key factor in star cluster evolution
Václav Pavlík (Astronomical Institute of the Czech Academy of Sciences)
Tuesday 30/01/2024 @ 14:00, Sala Antonio Sollima (IV piano Battiferro)
The conventional dynamical paradigm describing star clusters has been challenged. The internal kinematics of these systems was thought to be simply isotropic and non-rotating. However, recent high precision HST and Gaia observations have shown that star clusters are often characterised by internal rotation and anisotropic velocity distribution. We present the results of a suite of N-body simulations aimed at exploring the implications of an initially anisotropic velocity distribution on a number of fundamental dynamical aspects of the long-term evolution of star clusters. We focus on both the global properties (i.e., the evolution towards energy equipartition and mass segregation) and the stellar components (especially primordial and dynamically formed binary stars). In particular, we show that the rate of mass segregation, degree of energy equipartition, and the dependence of velocity dispersion on stellar mass significantly differ in isotropic and anisotropic systems.