Evidence for Mass-dependent Evolution of Transitional Dwarf Galaxies in the Virgo Cluster

TL;DR

This study investigates how environmental factors influence the evolution of transitional dwarf galaxies in the Virgo cluster, revealing mass-dependent morphological transformations and the role of ram pressure stripping.

Contribution

It provides new insights into the mass-dependent spatial distribution and evolutionary pathways of transitional dwarf galaxies in a galaxy cluster environment.

Findings

dS0s beyond 0.7R_vir show a decreasing fraction with distance, similar to dEs

ETdG(bc)s display an opposite trend to dS0s in spatial distribution

dS0s in the virialized region are brighter and more massive than dEs

Abstract

We present a study on the evolution of transitional dwarf galaxies, specifically dwarf lenticulars (dS0s) and early-type dwarfs with blue cores (ETdG(bc)s), driven by environmental processes in the Virgo cluster utilizing the Extended Virgo Cluster Catalog. We investigated the morphological fraction and stellar mass of transitional dwarf galaxies in relation to the clustercentric distance, compared to dwarf elliptical galaxies (dEs) and dwarf irregular galaxies (dIrrs). We found that dS0s beyond 0.7R_vir exhibit a similar trend in the morphology-clustercentric distance relation to dEs, demonstrating a decreasing fraction with clustercentric distance, whereas ETdG(bc)s display an opposite trend to dS0s. The spatial distributions of transitional dwarf galaxies and dEs correlate with the mass, in which fractions of bright, massive galaxies increase towards the central region of the Virgo cluster. In the mass-clustercentric distance plane, dS0s exhibit a skewed distribution that favors more massive galaxies than dEs at a given clustercentric distance. In the projected phase-space diagram, dS0s are scarce in the stripped region, whereas ETdG(bc)s are absent in both the stripped and virialized regions. In addition, the dS0s in the virialized region are predominantly brighter and more massive than the dEs, indicating that the transformation of dS0s into dEs depends on the stellar mass. We propose that the majority of observed dS0s constitute a population that has settled into the Virgo cluster, whereas ETdG(bc)s represent a recently accreted population. We discuss the impact of ram pressure stripping effects on mass-dependent morphological evolution.