A continuum of structure and stellar content from Virgo cluster early-type dwarfs to giants?

TL;DR

This study examines whether early-type dwarf and giant galaxies in the Virgo cluster form a continuous sequence in their structural and stellar properties, revealing deviations and discussing formation mechanisms.

Contribution

It provides an analysis of the relation between size, brightness, and color in Virgo early-type galaxies, highlighting deviations and potential unified formation processes.

Findings

Deviations from a simple continuum in size-brightness and color-magnitude relations.

Possible unified formation mechanisms for dwarfs and giants.

Comparison with models suggests similar processes could produce observed relations.

Abstract

Based on the wealth of multiwavelength imaging data from the SDSS, we investigate whether dwarf and giant early-type galaxies in the Virgo cluster follow a continuum in their structural parameters and their stellar population characteristics. More specifically we study the relation between size and brightness for the galaxies and their color magnitude relation. In both cases, we find noticeable deviations from a simple joint behavior of dwarfs and giants. We discuss these findings in the light of the different formation mechanisms commonly assumed for dwarf and giant early types, thereby taking into account the existence of several distinct early-type dwarf subclasses. By comparing our results to a semianalytic model of galaxy formation, we argue that the analyzed relations might be reproduced by processes that form dwarfs and giants altogether. The work presented here is based on Janz & Lisker 2008, 2009.