literature
Literature
Authors
Jobs
Seminars
Conferences
DataBETA

Star Clusters in M31: II. Old Cluster Metallicities and Ages from Hectospec Data

Jan, 2011
25 pages
Published in:
  • Astron.J. 141 (2011) 61
e-Print:
DOI:
View in:
pdf
reference search37 citations

Citations per year

2011201420172020202302468101214
Abstract: (arXiv)
We present new high signal-to-noise spectroscopic data on the M31 globular cluster system, obtained with the Hectospec multifiber spectrograph on the 6.5m MMT. More than 300 clusters have been observed at a resolution of 5A. The primary focus of this paper is the determination of mean cluster metallicities, ages and reddenings. Metallicities were estimated using a calibration of Lick indices with [Fe/H] provided by Galactic GCs. The metallicity distribution is not generally bimodal, in strong distinction with the bimodal Galactic globular distribution. Rather, the M31 distribution shows a broad peak, centered at [Fe/H]=-1, suggesting that the cluster systems of M31 and the Milky Way had different formation histories. Ages for clusters with [Fe/H] > -1 were determined using the automatic stellar population analysis program EZ_Ages. We find no evidence for massive clusters in M31 with intermediate ages. Moreover, we find that the mean ages of the old GCs are remarkably constant over about a decade in metallicity (-0.95 < [Fe/H] < 0.0). (abridged)
Note:
  • 25 pages, 24 figures, 3 tables
Loading ...