The Vcirc-sigma0 Relation of Galaxies

TL;DR

This paper investigates the relationship between maximum circular velocity and central velocity dispersion in galaxies, highlighting its importance for galaxy structure models and their ability to reproduce key scaling relations.

Contribution

It provides an interpretation of parameters in the Vcirc-sigma0 relation to aid data-model comparisons and future galaxy modeling efforts.

Findings

The Vcirc-sigma0 relation depends on galaxy morphology and light concentration.

Models must simultaneously reproduce the Vcirc-sigma0 relation and other scaling relations.

The paper offers a framework for interpreting parameters in the Vcirc-sigma0 relation.

Abstract

Courteau et al. (2007a) reported on the dependence of the ratio of a galaxy's maximum circular velocity, Vcirc, to its central velocity dispersion, sigma0, on morphology, or equivalently total light concentration. This Vcirc-sigma0 concentration relation, which involves details about the local and global galaxy physics, poses a fundamental challenge for galaxy structure models. Furthermore, not only must these models reproduce the Vcirc-sigma0 relation and its various dependences, they must simultaneously match other fundamental scaling relations such as the velocity-size-luminosity and color-luminosity relations of galaxies. We focus here on the interpretation of parameters that enter the Vcirc-sigma0 relation to enable proper data-model comparisons and follow-up studies by galaxy modelers and observers.