1999/11/09 by P. Barmby, J. P. Huchra, J. P. Brodie +7 · 7 citations
Physics and Astronomy · #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/301213
published as Astron.J. 119 (2000) 727 · Accepted to AJ; 58 pages, including 10 tables and 22 figures. Tables 1, 2, 4 and 5 have been truncated to save trees; tex for the full tables included in the source, contact the first Author to acquire the data contained within
arxiv created 1999/11/09 · openalex publication_date 2000/02/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
We present a new catalog of photometric and spectroscopic data on M31 globular clusters (GCs). The catalog includes new optical and near-infrared photometry for a substantial fraction of the 435 clusters and cluster candidates. We use these data to determine the reddening and intrinsic colors of individual clusters, and we find that the extinction laws in the Galaxy and M31 are not significantly different. There are significant (up to 0.2 mag in V - K ) offsets between the clusters' intrinsic colors and simple stellar population colors predicted by population synthesis models; we suggest that these are due to systematic errors in the models. The distributions of M31 clusters' metallicities and metallicity-sensitive colors are bimodal, with peaks at [Fe/H] ≈ -1.4 and -0.6. The distribution of V - I is often bimodal in elliptical galaxies' globular cluster systems, but it is not sensitive enough to metallicity to show bimodality in M31 and Galactic cluster systems. The radial distribution and kinematics of the two M31 metallicity groups imply that they are analogs of the Galactic "halo" and "disk/bulge" cluster systems. The globular clusters in M31 have a small radial metallicity gradient, suggesting that some dissipation occurred during the formation of the globular cluster system. The lack of correlation between cluster luminosity and metallicity in M31 GCs shows that self-enrichment is not important in GC formation.