Stellar populations of seven early-type dwarf galaxies and their nuclei

TL;DR

This study analyzes the stellar populations of seven nucleated dwarf elliptical galaxies and their nuclei using optical spectra, revealing that nuclei tend to be slightly younger but share similar metallicities with their host galaxies.

Contribution

It provides new insights into the stellar population differences between nuclei and host galaxies in nucleated dwarf ellipticals using integrated spectral analysis.

Findings

Nuclei have slightly lower luminosity-weighted ages than their host galaxies.

No significant metallicity differences between nuclei and host galaxies.

Stellar populations in dwarf ellipticals are more complex than previously thought.

Abstract

Dwarf galaxies are the numerically dominating population in the dense regions of the universe. Although they seem to be simple systems at first view, the stellar populations of dwarf elliptical galaxies (dEs) might be fairly complex. Nucleated dEs are of particular interest, since a number of objects exhibit different stellar populations in their nuclei and host galaxy. We present stellar population parameters obtained from integrated optical spectra using a Lick index analysis of seven nucleated dwarf elliptical galaxies and their nuclei. After subtracting the scaled galaxy spectra from the nucleus spectra, we compared them with one another and explore their stellar populations. As a preliminary result, we find that the luminosity weighted ages of the nuclei slightly lower than those of galaxies, however, we do not see any significant difference in metallicity of the host galaxies and their nuclei.