The Gaia DR3 view of dynamical substructure in the stellar halo near the Sun

Understand

The debris from past merger events is expected and, to some extent, known to populate the stellar halo near the Sun.

• We aim to identify and characterise such merger debris using Gaia DR3 data supplemented by metallicity and chemical abundance information from LAMOST LRS and APOGEE for halo stars within 2.5 kpc from the Sun.
• We utilise a single linkage-based clustering algorithm to identify over-densities in Integrals of Motion space that could be due to merger debris.
• Combined with metallicity information and chemical abundances, we characterise these statistically significant over-densities.