Hot Stars in Old Stellar Populations: A Continuing Need for Intermediate Ages
Abstract
We investigate the effect of a small contamination of hot, old, metal-poor starlight on the inferred stellar populations of early-type galaxies in the core of the Coma Cluster. We find that the required correction to the Balmer and metal absorption-line strengths for old, metal-poor stars does not significantly affect the inferred age of the stellar population when the Hbeta strength is large. Intermediate-aged populations are therefore still needed to explain enhanced Balmer-line strengths in early-type galaxies. This gives us increased confidence in our age estimates for these objects. For galaxies with weak Balmer-line strengths corresponding to very old populations (t>10 Gyr), however, a correction for hot stars may indeed alter the inferred age, as previously suggested. Finally, the inferred metallicity [Z/H] will always be higher after any correction for old, metal-poor starlight than without, but the enhancement ratios [E/Fe] will strengthen only slightly.
Cite
@article{arxiv.astro-ph/0506336,
title = {Hot Stars in Old Stellar Populations: A Continuing Need for Intermediate Ages},
author = {S. C. Trager and Guy Worthey and S. M. Faber and Alan Dressler},
journal= {arXiv preprint arXiv:astro-ph/0506336},
year = {2009}
}
Comments
8 pages, 3 figures (2 in color); accepted for publication in MNRAS