The ACS Survey of Galactic Globular Clusters. III. The Double Subgiant Branch of NGC 1851

Abstract

Photometry with HST's ACS reveals that the subgiant branch (SGB) of the globular cluster NGC 1851 splits into two well-defined branches. If the split is due only to an age effect, the two SGBs would imply two star formation episodes separated by $\sim$ 1 Gyr. We discuss other anomalies in NGC 1851 which could be interpreted in terms of a double stellar population. Finally, we compare the case of NGC 1851 with the other two globulars known to host multiple stellar populations, and show that all three clusters differ in several important respects.

22 pages, 7 figures, accepted for pubblication on ApJ

References in corpus (7)

• The ACS Survey of Galactic Globular Clusters: M54 and Young Populations in the Sagittarius Dwarf Spheroidal Galaxy
• NGC 6441: another indication for a very high helium content in Globular Cluster stars
• The Peculiar Horizontal Branch Morphology of the Galactic Globular Clusters NGC 6388 and NGC 6441: new insights from UV observations
• On the Origin of the High Helium Sequence in $\omega$ Centauri
• The Chemical Evolution of Helium in Globular Clusters: Implications for the Self-Pollution Scenario
• The absolute motion of the peculiar cluster NGC6791
• Newly Identified Star Clusters in M33. I. Integrated Photometry and Color-Magnitude Diagrams

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