CN Anomalies in the Halo System and the Origin of Globular Clusters in the Milky Way

TL;DR

This study investigates the origins of CN-strong halo stars in the Milky Way, suggesting they likely originate from disrupted globular clusters and are associated with the inner-halo population based on their kinematic properties.

Contribution

It provides evidence linking CN-strong halo stars to globular clusters and the inner-halo population through orbital analysis, highlighting the role of cluster disruption in halo formation.

Findings

CN-strong stars share kinematics with inner-halo stars

Globular clusters and CN-strong stars have similar orbital properties

Stripped globular clusters significantly contribute to the inner halo

Abstract

We explore the kinematics and orbital properties of a sample of red giants in the halo system of the Milky Way that are thought to have formed in globular clusters, based on their anomalously strong UV/blue CN bands. The orbital parameters of the CN-strong halo stars are compared to those of the inner- and outer-halo populations as described by Carollo et al., and to the orbital parameters of globular clusters with well-studied Galactic orbits. The CN-strong field stars and the globular clusters both exhibit kinematics and orbital properties similar to the inner-halo population, indicating that stripped or destroyed globular clusters could be a significant source of inner-halo field stars, and suggesting that both the CN-strong stars and the majority of globular clusters are primarily associated with this population.