Building Up the Globular Cluster System of the Milky Way: The Contribution of the Sagittarius Galaxy

We demonstrate that there is a clear statistical correlation between the(X,Y,Z,V_r) phase-space distribution of the outer halo Galactic globularclusters (having 10 kpc <= R_GC <= 40 kpc) and the orbital path of theSagittarius dwarf spheroidal galaxy (Sgr dSph), as derived by Ibata & Lewis. Atleast 4 of the sample of 35 globular clusters in this distance range wereformerly members of the Sgr galaxy (at the 95 % confidence level), and are nowdistributed along the Sgr Stream, a giant tidal structure that surrounds theMilky Way. This is the first instance that a statistically significantstructure associated with the Sgr dSph has been detected in the globularcluster population of the Galactic halo. Together with the four well-knownglobular clusters that are located near the center of this tidally-disruptingdwarf galaxy, these clusters constitute ~ 20 % of the population of outer halo(R_GC >= 10 kpc) clusters. The Sgr dSph was therefore not only an importantcontributor to the halo field star population, but it also had a significantrole in the building-up of the globular cluster system of the Milky Way.Comment: 13 pages, 5 .ps figures. AAS Latex. emulateapj5.sty macro included. Accepted by The Astronomical Journa