Program: GS-2009A-Q-11

Title:Environment and the Formation of Dwarf Elliptical Galaxies: A Unified Study of Field Stars, Stellar Nuclei and Globular Clusters
PI:Eric Peng
Co-I(s): Thomas Puzia, Andres Jordan, Patrick Cote, Laura Ferrarese

Abstract

Dwarf elliptical galaxies (dEs) are the present-day representatives of a fundamental component of galaxy assembly, and studying their stellar populations is one of the only ways to understand the early formation of stars in low mass halos. Early-type dwarfs are locally most numerous in the nearby Virgo Cluster, and high resolution imaging from the ACS Virgo Cluster Survey has produced two surprising results: 1) The masses of stellar nuclei fall on the same scaling relation as that defined by supermassive black holes, and 2) The specific frequency of globular clusters (GCs) in dEs is higher toward the center of the galaxy cluster, suggesting that central dwarfs had rapid and intense early star formation. The formation of nuclear star clusters and GCs is intimately linked to the formation of the dwarfs themselves, and yet there has been no study that tie high-quality data on all three components into a unified picture of cluster dE formation. We propose to use the GMOS-S/IFU to obtain deep integrated spectra of 10 Virgo dEs, a continuation of our 2008A program, requesting a total of 20.97 hrs. We will measure abundance ratios ([alpha/Fe]) and mean ages for both the nuclear and low surface brightness non-nuclear light. These observations will test how the cluster environment affects the duration and timing of star formation in dEs and their nuclei, and how that connects with the formation of their globular cluster systems.

Publications using this program's data