Understanding the Fundamental Plane and the Tully Fisher Relation

TL;DR

This paper explores the origins and variations of the fundamental plane and Tully-Fisher relation in galaxies, linking galaxy properties to their formation history, structure, and dark matter content.

Contribution

It provides new insights into how galaxy formation processes influence the tilt and scatter of these fundamental scaling relations.

Findings

Correlation between surface brightness and galaxy youth.

Tilt of the fundamental plane linked to stellar mass, age, and metallicity.

Complexity of the Tully-Fisher relation due to bulge and disk components.

Abstract

The relation between early type galaxy size, surface brightness and velocity dispersion, "the fundamental plane", has long been understood as resulting from equilibrium in their largely pressure supported stellar dynamics. The dissipation and feedback involved in reaching such an equilibrium through merger formation of these galaxies over cosmic time can be responsible for the orientation of the plane. We see a correlation between surface brightness enhancement and youth in the 6dF Galaxy Survey. Correlations of this `tilt' with stellar mass, age, concentration, shape and metallicity now point the direction for further work on the resolved kinematics and structure of these nearby galaxies and on their initial mass function and dark matter component. On the face of it, the Tully Fisher relation is a simpler one dimensional scaling relation. However, as late type galaxies have bulges as well as disks, and, as the surface density of disks is only standard for the more massive galaxies, additional parameters are involved.