A Shared Tully-Fisher Relation for Spiral and S0 Galaxies

TL;DR

This study compares the Tully-Fisher relations of spiral and S0 galaxies using two velocity measures, finding no significant differences, which challenges existing theories of S0 galaxy formation.

Contribution

It provides the first direct comparison of Tully-Fisher relations for S0 and spiral galaxies using detailed kinematic models and multiple velocity measures.

Findings

No significant difference in Tully-Fisher relations between S0 and spiral galaxies.

Both galaxy types follow similar relations when plotted against brightness and stellar mass.

Results challenge naive expectations of S0 formation theories.

Abstract

We measure the Tully-Fisher relations of 14 lenticular galaxies (S0s) and 14 spirals. We use two measures of rotational velocity. One is derived directly from observed spatially-resolved stellar kinematics and the other from the circular velocities of mass models that include a dark halo and whose parameters are constrained by detailed kinematic modelling. Contrary to the naive expectations of theories of S0 formation, we find no significant difference between the Tully-Fisher relations of the two samples when plotted as functions of both brightness and stellar mass.