On the tilt of Fundamental Plane by Clausius' virial maximum theory

TL;DR

This paper refines the Clausius' virial maximum theory for explaining the Fundamental Plane of early type galaxies by incorporating more realistic stellar models, providing deeper insight into the FP tilt and its cosmological implications.

Contribution

It advances the CV theory by modeling the stellar component with a King profile, enhancing understanding of the FP tilt and its degeneracy within a CDM cosmology.

Findings

The refined model explains the FP tilt more accurately.

The theory accounts for the FP degeneracy in a CDM universe.

Comparison methods for observed and predicted FPs are proposed.

Abstract

The theory of the Clausius' virial maximum to explain the Fundamental Plane (FP) proposed by Secco (2000, 2001,2005) is based on the existence of a maximum in the Clausius' Virial (CV) potential energy of a early type galaxy (ETG) stellar component when it is completely embedded inside a dark matter (DM) halo. At the first order approximation the theory was developed by modeling the two-components with two cored power-law density profiles. An higher level of approximation is now taken into account by developing the same theory when the stellar component is modeled by a King-model with a cut-off. Even if the DM halo density remains a cored power law the inner component is now more realistic for the ETGs. The new formulation allows us to understand more deeply what is the dynamical reason of the FP tilt and in general how the CV theory may really be the engine to produce the FP main features. The degeneracy of FP in respect to the initial density perturbation spectrum may be now full understood in a CDM cosmological scenario. A possible way to compare the FPs predicted by the theory with those obtained by observations is also exemplified.