Formation of Galactic Disk Globular Clusters in Early Dissipative Minor Merging

The origin of metal-rich, highly flattened, and rapidly rotating diskglobular cluster system in the Galaxy is one of longstanding issues in thecontext of the Galaxy formation. Our numerical simulations suggest a new``two-fold'' scenario that the disk globular clusters are firstly formed in thehigh-pressure, dense central region of a gas-rich dwarf galaxy, as inducedduring the tidal interaction with the pre-existing, young thin disk of theGalaxy, and then dispersed into the disk region owing to the final tidaldestruction of the merging dwarf. We also demonstrate that spatialdistribution, total number, and metallicity distribution of the clusters formedin this minor merging depend on the mass ratio of the host to dwarf galaxy andthe orbital configuration of merging. Based on these results, we discusswhether a minor merging event about 10 Gyr ago can explain both the Galacticthick disk and the disk globular clusters. Several other implications for thepossible relation between the properties of disk galaxies and their diskglobular clusters are also discussed.Comment: 18 pages 5 figures, 2002, ApJ 566, 24