Rediscovering the origins of the stellar halo with chemical tagging

TL;DR

This paper explores the complex origins of the Galactic stellar halo by using chemical tagging to identify stars originating from globular clusters, shedding light on the halo's assembly history.

Contribution

It introduces a method to recognize halo stars from globular clusters via their unique chemical signatures, aiding understanding of the halo's formation.

Findings

Globular cluster stars can be identified in the halo by their light element abundance anticorrelations.

Chemical tagging can estimate the contribution of globular clusters to the halo.

The approach constrains globular cluster formation pathways.

Abstract

The Galactic halo has a complex assembly history, which can be seen in its wealth of kinematic and chemical substructure. Globular clusters lose stars through tidal interactions with the Galaxy and cluster evaporation processes, meaning that they are inevitably a source of halo stars. These "migrants" from globular clusters can be recognized in the halo field by the characteristic light element abundance anticorrelations that are commonly observed only in globular cluster stars, and the number of halo stars that can be chemically tagged to globular clusters can be used to place limits on the formation pathways of those clusters.