2005/02/25 by L. Secco
Physics and Astronomy · #Astrophysics #Black Holes and Theoretical Physics #Classical mechanics #Cosmology and Gravitation Theories #Dark matter #Fundamental plane (elliptical galaxies) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Lenticular galaxy #Physics #Statistical physics #Theoretical physics #Virial theorem #astro-ph
paper · pdf · doi:10.1016/j.newast.2005.02.003
published as New Astron. 10 (2005) 439-461 · 42 pages, 7 figures, in press in New Astronomy 2005
openalex publication_date 2005/02/25 · arxiv created 2005/03/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The paper confirms the existence of a special configuration (among the infinite number of virial states) which a B stellar(Baryonic) component may assume inside a given D dark halo potential well.This satisfies the d'Alembert Principle of virtual works and its typical dimension works as a scale length (tidal radius)induced on the gravitational field of the bright component by the dark one.Its dynamic and thermodynamic properties are here analyzed in connection with the physical reason for the existence of the Fundamental Plane (FP) for ellipticals.The analysis is performed by using 2-component models with two power-law density profiles and two homogeneous cores and compared with some observable scaling relations for pressure supported ellipticals.The virial equilibrium stages of the 2-component system have to occur after a previous violent relaxation phase. If the stellar B component is allowed to cool slowly its virial evolution consists of a sequence of contractions with enough time to rearrange the virial equilibrium after any step. The thermodynamic process during the dynamical evolution is so divided into a sequence of transformations which are irreversible but occur between two quasi-equilibrium stages.The analysis allows the conclusion that the induced scale length is a real confinement for the stellar system. The presence of this specific border on the space of the baryonic luminous component has to be regarded as the physical reason why a stellar galaxy belongs to the FP and why astrophysical objects, with a completely different history and formation, but characterized by a tidal radius (as the globular clusters are) lie on the same FP. An other problem addressed is how this special configuration may be reached and why an elliptical is not completely relaxed in respect to its dark halo.