Keck Spectroscopy of Red Giant Stars in the Vicinity of M31'sMassive Globular Cluster G1

We present results from a Keck spectroscopic survey of red giants in a fieldnear M31's major axis, ~34kpc in projection from the nucleus, near the globularcluster G1. We use multislit LRIS spectroscopy to measure the CaII triplet in41 stars with apparent mags 20=-0.8 for thesepotential M31 outer disk stars. Six of the 23 M31 members v and [Fe/H] valuesconsistent with those of G1 (after accounting forits intrinsic spread in both):one of these stars lies within G1's projected tidal radius and is a likelymember; the remaining 5 stars are not physically close to G1 but may representits tidal debris. More data are needed to confirm the nature of these 5 starsas it is likely that they represent M31's smooth halo population. We might haveexpected to detect tidal debris if G1 were the remnant core of a dwarf galaxybeing accreted by M31; instead, the majority of M31 giants in this field aremetal-rich and belong to what is evidently the outer disk of M31, and only asmall fraction (<~20%) could possibly have originated in G1.Comment: 11 pages, 2 figures, accepted for publication in the A