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Helium-Core White Dwarfs in Globular Clusters

Brad Hansen·Vassiliki Kalogera·Frederic A. Rasio
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Abstract

We examine the theoretical implications of a population of low-mass helium-core white dwarfs in globular clusters. In particular, we focus on the observed population in the core of NGC 6397, where several low-mass white dwarf canditates have been identified as ``non-flickerers'' by Cool and collaborators. Age and mass estimates from cooling models, combined with dynamical and evolutionary considerations, lead us to infer that the dark binary companions are C/O white dwarfs rather than neutron stars. Furthermore, we find that the progenitor binaries very likely underwent an exchange interaction within the last 1.e9 years. We examine the prospects for detecting a similar population in other globular clusters, with particular attention to the case of 47 Tuc.

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Brad Hansen, Vassiliki Kalogera, Frederic A. Rasio. 2002-06-03. Helium-Core White Dwarfs in Globular Clusters. https://doi.org/10.1086/367827

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