Globular Clusters in Early-Type Galaxies with GMOS
Abstract
We present recent results from our long-term Gemini/GMOS study of globular clusters in early-type galaxies. To date, we have obtained photometry and spectroscopy for clusters in NGCs 3379, 4649, 524, 7332, and IC 1459. We find a clear bimodality in the NGC 4649 cluster colour distribution, with the fraction of blue/red clusters increasing with galactocentric radius. We derive ages and metallicities for 22 clusters in NGC 3379, finding that most of the clusters appear old (10-15 Gyr); however, there is a group of 4 metal-rich, younger clusters with ages of 2-6 Gyr. The NGC 3379 cluster velocity dispersion decreases with radius, as does the inferred (local) mass-to-light ratio: there is no evidence for a dark matter halo in NGC 3379 based on our globular cluster data.
Cite
@article{arxiv.astro-ph/0310324,
title = {Globular Clusters in Early-Type Galaxies with GMOS},
author = {Terry Bridges and Mike Beasley and Favio Faifer and Duncan Forbes and Juan Forte and Karl Gebhardt and Dave Hanes and Ray Sharples and Steve Zepf},
journal= {arXiv preprint arXiv:astro-ph/0310324},
year = {2007}
}
Comments
3 pages, 2 figures, uses newpasp.sty (included). 'In press' for "Joint Discussion #6: Extragalactic Globular Clusters and their Host Galaxies", IAU General Assembly, July 2003. Editors: T. Bridges and D. Forbes