Galaxy Dynamics
On the Galaxy Fundamental Plane of Early–Type Galaxies. A New Interpretation of the Enigma Volume 2

Area 02 – Scienze fisiche

The aim is to widely discuss the Fundamental Plane (FP) of galaxies. The theoretical interpretation is still an open problem even if the relevance has always been great since its discovery in 1987. A review of some interpretative analyzes of the main enigmatic features are firstly considered, without an exhaustive explanation. A new strategy is then exposed starting from the ongoing question about the galaxy end–state after violent relaxation. The approach is based on the addition of a dark matter halo (D) to the stellar (B) component. The key to solve the issue about the term to be added at virial equilibrium together with the self bright potential energy, lies into the Clausius’ virial energy (CV). Its most important property is to be a non–monotonic function of the B dimension within that fixed of D, but to reach a maximum corresponding to a minimum of macroscopic pressure substaining B and maximizing its entropy. The theory of CV maximum is then performed with linear and non–linear models reproducing the main features of FP together with ZOE equation, mass–size, Faber–Jackson and Kormendy relationships. The extension to all virialized two–component structures from globular clusters to galaxy clusters has to be expected. The cosmic environments without DM and including Cold, Hot, Warm DM are finally reviewed. This last seems the most suitable for the new theory.

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