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arXiv · 0909.4677

Complexity in small-scale dwarf spheroidal galaxies

Andreas Koch·Daniel Adén·Eva K. Grebel·Sofia Feltzing
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Abstract

Our knowledge about the chemical evolution of the more luminous dwarf spheroidal (dSph) galaxies is constantly growing. However, little is known about the enrichment of the ultrafaint systems recently discovered in large numbers in large Sky Surveys. Low-resolution spectroscopy and photometric data indicate that these galaxies are predominantly metal-poor. On the other hand, the most recent high-resolution abundance analyses indicate that some of these galaxies experienced highly inhomogenous chemical enrichment, where star formation proceeds locally on the smallest scales. Furthermore, these galaxy-contenders appear to contain very metal-poor stars with [Fe/H]<-3 dex and could be the sites of the first stars. Here, we consider the presently available chemical abundance information of the (ultra-) faint Milky Way satellite dSphs. In this context, some of the most peculiar element and inhomogeneous enrichment patterns will be discussed and related to the question of to what extent the faintest dSph candidates and outer halo globular clusters could have contributed to the metal-poor Galactic halo.

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Andreas Koch, Daniel Adén, Eva K. Grebel, Sofia Feltzing. 2009-09-25. Complexity in small-scale dwarf spheroidal galaxies. https://doi.org/10.1017/s174392131000061x

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