Red giant depletion in globular cluster cores

Abstract

We investigate the observed depletion of red giants in the cores of post-core-collapse globular clusters. In particular, the evolutionary scenario we consider is a binary consisting of two low-mass stars which undergoes two common envelope phases. The first common envelope phase occurs when the primary is a red giant resulting in a helium white dwarf and main sequence star in a detached binary. The second common envelope phase occurs shortly after the secondary becomes a red giant. During the second common envelope phase the degenerate helium cores merge resulting in a core mass greater than the helium burning limit and the formation of a horizontal branch star. We show that this evolutionary route is enhanced in post-core-collapse clusters by stellar encounters. These encounters increase the population of binary secondaries which would have evolved onto the red giant branch in the recent past.

6 pages, 5 figures, submitted to MNRAS

References in corpus (1)

• The Origin of Subdwarf B Star (I): the Formation Channels

Cited by in corpus (5)

• Dissecting the Colour-Magnitude Diagram: A Homogeneous Catalogue of Stellar Populations in Globular Clusters
• From Canonical to Enhanced Extra Mixing in Low-Mass Red Giants: Tidally Locked Binaries
• Stellar Populations in Globular Cluster Cores: Evidence for a Peculiar Trend Among Red Giant Branch Stars
• Modeling Dense Stellar Systems
• Tidal Interactions of Red Giants with Environment Stars in Globular Clusters