Abstract
Astrophysical systems will never be in a real thermodynamic equilibrium: they undergo an evaporation process due to the fact that the gravity is not able to confine the particles. Ordinarily, this difficulty is overcome by enclosing the system in a rigid container which avoids the evaporation. We propose an energetic prescription which is able to confine the particles, leading in this way to an alternative version of the Antonov isothermal model which unifies the well-known isothermal and polytropic profiles. Besides the main features of the isothermal sphere model (the existence of the gravitational collapse and the energetic region with a negative specific heat), this alternative model has the advantage that the system size naturally appears as a consequence of the particles’ evaporation.
- Received 2 May 2003
DOI:https://doi.org/10.1103/PhysRevE.68.066116
©2003 American Physical Society