Open AccessVirial equilibrium states of spheroidal stellar systems
Author(s) -
Fu Y. N.,
Sun Y. S.
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02290.x
Subject(s) - physics , virial theorem , tensor (intrinsic definition) , classical mechanics , diagonal , virial coefficient , homogeneous , mathematical physics , statistical physics , astrophysics , thermodynamics , galaxy , geometry , mathematics
In this paper, we present virial equilibrium states of spheroidal stellar systems and study their linear stability. We consider the cases of both homogeneous and a particular class of heterogeneous spheroids. It is assumed that K 11 =K 22 =α K 33 , where K ii is the i th diagonal element of the kinetic‐energy tensor and α a positive constant. The semi‐axes of the considered spheroidal stellar systems satisfy a set of reversible ordinary differential equations derived from the non‐stationary tensor virial theorem. For each α, there exists a unique equilibrium state that is linearly stable under our assumptions. The equilibrium configuration is prolate, spherical and oblate if α <1, α =1 and α >1, respectively.