How similar is the stellar structure of low-mass late-type galaxies to that of early-type dwarfs?

TL;DR

This study compares the structural properties of low-mass late-type galaxies with early-type dwarfs, revealing size differences influenced by environment and suggesting possible evolutionary links.

Contribution

It provides a detailed comparison of galaxy structures across types and environments, highlighting how environmental factors may drive morphological transformation.

Findings

Late-type galaxies have larger inner and outer structures than early-type dwarfs at the same stellar mass.

Environmental density affects galaxy sizes, with high-density environments producing smaller structures.

Structural similarities increase in high-density environments, implying environmental processes influence galaxy evolution.

Abstract

We analyse structural decompositions of 500 late-type galaxies (Hubble $T$-type $\ge 6$) from the Spitzer Survey of Stellar Structure in Galaxies (S$^4$G), spanning a stellar mass range of about $10^7$ to a few times $10^{10}$ M$_\odot$. Their decomposition parameters are compared with those of the early-type dwarfs in the Virgo cluster from Janz et al. They have morphological similarities, including the fact that the fraction of simple one-component galaxies in both samples increases towards lower galaxy masses. We find that in the late-type two-component galaxies both the inner and outer structures are by a factor of two larger than those in the early-type dwarfs, for the same stellar mass of the component. While dividing the late-type galaxies to low and high density environmental bins, it is noticeable that both the inner and outer components of late types in the high local galaxy density bin are smaller, and lie closer in size to those of the early-type dwarfs. This suggests that, although structural differences between the late and early-type dwarfs are observed, environmental processes can plausibly transform their sizes sufficiently, thus linking them evolutionarily.