Home List of Titles The age, metallicity and α-element abundance of Galactic globular clusters from single stellar population models
Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/37197
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- The age, metallicity and α-element abundance of Galactic globular clusters from single stellar population models
- Mendel, Jon T.; Proctor, Robert N.; Forbes, Duncan A.
- Establishing the reliability with which stellar population parameters can be measured is vital to extragalactic astronomy. Galactic globular clusters (GCs) provide an excellent medium in which to test the consistency of single stellar population (SSP) models as they should be our best analogue to a homogeneous (single) stellar population. Here we present age, metallicity and alpha-element abundance measurements for 48 Galactic GCs as determined from integrated spectra using Lick indices and SSP models from Thomas, Maraston & Korn, Lee & Worthey and Vazdekis et al. By comparing our new measurements to independent determinations we are able to assess the ability of these SSPs to derive consistent results - a key requirement before application to heterogeneous stellar populations like galaxies. We find that metallicity determinations are extremely robust, showing good agreement for all models examined here, including a range of enhancement methods. Ages and alpha-element abundances are accurate for a subset of our models, with the caveat that the range of these parameters in Galactic GCs is limited. We are able to show that the application of published Lick index response functions to models with fixed abundance ratios allows us to measure reasonable alpha-element abundances from a variety of models. We also examine the age-metallicity and [alpha/Fe]-metallicity relations predicted by SSP models, and characterize the possible effects of varied model horizontal branch morphology on our overall results.
- Publication type
- Journal article
- Research centre
- Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing
- Monthly Notices of the Royal Astronomical Society, Vol. 379, no. 4 (Jul 2007), p. 1618-1636
- Publication year
- Abundances; Galactice globular clusters; GCs; Globular clusters; Single stellar population models; SSP models; Stars
- Blackwell Publishing
- Publisher URL
- Copyright © 2007 Royal Astronomical Society. Author's final draft reproduced here in accordance with the copyright policy of the publisher.
- Full text
- Peer reviewed