Globular Cluster and Galaxy Formation: M31, the Milky Way, and Implications for Globular Cluster Systems of Spiral Galaxies

  title={Globular Cluster and Galaxy Formation: M31, the Milky Way, and Implications for Globular Cluster Systems of Spiral Galaxies},
  author={David Burstein and Yong Li and Kenneth C. Freeman and John E. Norris and Michael S. Bessell and Joss Bland-Hawthorn and Brad K. Gibson and Michael A. Beasley and Hyun-chul Lee and Beatriz Barbuy and John Peter Huchra and Jean P. Brodie and Duncan A. Forbes},
  journal={The Astrophysical Journal},
  pages={158 - 166}
We find that the globular cluster (GC) systems of the Milky Way and of our neighboring spiral galaxy, M31, comprise two distinct entities, differing in three respects. First, M31 has a set of young GCs, ranging in age from a few times 102 Myr to 5 Gyr old, as well as old GCs. No such very young GCs are known in the Milky Way. Second, we confirm that the oldest M31 GCs have much higher nitrogen abundances than do Galactic GCs at equivalent metallicities, while carbon abundances appear normal for… 

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