Colloquium – Deimer Alvarez – Omega Centauri: a chemical perspective to understand its history

Nowadays we know that Globular Clusters (GCs) are formed by multiple populations (MPs) with different light element abundances (C, N, O, Na, Mg, Al, Si, K) within the cluster stars, that are structured in well-defined patterns, such as the Na-O and Mg-Al anticorrelations. The evidence is interpreted as the signature of a self-enrichment process within the cluster, where a second population of stars was formed from material processed in the first population (or polluter) stars through the hot CNO cycle and its secondary NeNa and MgAl chains. A detailed study of these chemical anomalies is one of the paths to disentangle among the polluters proposed in the literature. In this sense, ω Centauri represents an ideal laboratory since this GC-like system exhibits magnified all the chemical anomalies usually observed in normal GCs. However, this system has a more complex history than a typical GC since it is probably the nuclear star cluster of a disrupted dwarf galaxy.
In this talk, through a chemical perspective I will show 1) how the outcomes of the MgAl chain can help to put more constraints on the nature of polluters responsible for the formation of MPs, and 2) what can we learn about the history of ω Centauri thanks to its metallicity distribution.