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تسجيل مستخدم جديد${S}^5$: The destruction of a bright dwarf galaxy as revealed by the chemistry of the Indus stellar stream
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The recently discovered Indus stellar stream exhibits a diverse chemical signature compared to what is found for most other streams due to the abundances of two outlier stars, Indus$_$0 and Indus$_$13. Indus$_$13, exhibits an extreme enhancement in rapid neutron-capture ($r$-)process elements with $mathrm{[Eu/Fe]} = +1.81$. It thus provides direct evidence of the accreted nature of $r$-process enhanced stars. In this paper we present a detailed chemical analysis of the neutron-capture elements in Indus$_$13, revealing the star to be slightly actinide poor. The other outlier, Indus$_0$, displays a globular cluster-like signature with high N, Na, and Al abundances, while the rest of the Indus stars show abundances compatible with a dwarf galaxy origin. Hence, Indus$_0$ provides the first chemical evidence of a fully disrupted dwarf containing a globular cluster. We use the chemical signature of the Indus stars to discuss the nature of the stream progenitor which was likely a chemically evolved system, with a mass somewhere in the range from Ursa Minor to Fornax.
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