Effect of suprathermal particles on gravothermal oscillation

Evolution of a gravitational 1000-body system is calculated to analyze gravothermal oscillation in discrete particle systems. It is found that suprathermal particles are produced as a result of binary hardenings which transfer their energy to the mean field particles very slowly. Therefore, three modes share the total energy. They are: (1) energy of the mean field which controls global configuration of the system; (2) energy of correlations whose development releases binding energies of binaries and triggers explansion; and (3) energy of suprathermal particles which plays a role of an additional energy reservoir acting as a buffer to avoid a sudden and great amount of energy input from the developing correlations to the mean field. Because of the moderately large number of particles the energy transport between the core and the halo is better analyzed than in our previous work on a 100-body system. It is concluded that the distribution of inwardly decreasing temperature and the associated heat flow towards the central core drive the gravothermal expansion quite similarly as in the gravothermal oscillation of gaseous models. (author)