http://arxiv.org/abs/1804.09819
The origin of multiple stellar populations in globular clusters remains a mystery. We investigate the possibility that nuclear star clusters of dwarf galaxies may be the progenitors of the massive globular clusters of a central galaxy by examining the galactic nuclei formed in cosmological galaxy formation simulations. We derive structural properties of these nuclear regions, including mass, size, rotation, and shape. By using theoretical supernova yields to model the supernova enrichment in the simulations, we obtain individual elemental abundances for Fe, O, Na, Mg, and Al. Our nuclei are systematically more metal-rich than their host galaxies, which lie on the expected mass-metallicity relation. Some nuclei have a spread in Fe comparable to the anomalous globular clusters of the Milky Way, such as $\omega$ Cen and M54, lending support to the hypothesis that nuclear star clusters of dwarf galaxies could be the progenitors of these objects. None of our nuclear regions contain the light element abundance spreads that characterize globular clusters, even when a large age spread is present. Our results demonstrate that extended star formation history within clusters, with metal pollution provided solely by supernova ejecta, is not able to produce the multiple populations present in globular clusters.
G. Brown, O. Gnedin and H. Li
Fri, 27 Apr 18
-28/64
Comments: 10 pages, 12 figures, submitted to ApJ
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