Program: GN-2012B-Q-77

Globular clusters (GCs) are fossil relics from which we can obtain critical insights into the merger and accretion events that underlie hierarchical galaxy assembly. As part of the ongoing Pan-Andromeda Archaeological Survey (PAndAS) we have discovered several groups of GCs that closely trace narrow stellar debris streams in the outer halo of M31. These clearly represent distinct accreted families of GCs - the only known examples apart from the few Milky Way objects arriving via the Sagittarius dwarf. We are undertaking a detailed program of study of these families, including investigation of their dynamics via radial velocity measurements. Here we target faint members of the most prominent GC overdensity in the M31 halo, an association which also includes the famous cluster G1 - long suspected to be the stripped nucleus of a former dwarf galaxy. Our kinematic measurements will determine unambiguously whether the GCs in this overdensity are related to each other, and hence whether they point to the final remains of one of the elusive progenitors of the M31 halo streams. With appropriate modelling our full sample of GC velocities, of which the present targets form a part, will also allow us to derive a new dynamical mass for M31.