Abstract / Description of output
A new population of extended, luminous globular clusters has recently
been discovered in the outskirts of M31. These objects have luminosities
typical of classical globular clusters, but much larger half-light
radii. We report the first results from deep ACS imaging of four such
clusters, one of which is a newly discovered example lying at a
projected distance of ~60 kpc from M31. Our F606W, F814W color-magnitude
diagrams extend ~3 mag below the horizontal branch level, and clearly
demonstrate, for the first time, that all four clusters are composed of
>~10 Gyr old, metal-poor stellar populations. No evidence for
multiple populations is observed. From a comparison with Galactic
globular cluster fiducials we estimate metallicities in the range
-2.2
Original language | English |
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Journal | Astrophysical Journal |
Volume | 653 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Dec 2006 |
Keywords / Materials (for Non-textual outputs)
- Galaxies: Individual: Messier Number: M31
- Galaxies: Star Clusters
- Galaxy: Globular Clusters: General