Mergers and globular-cluster formation in early-type galaxies

Major mergers of gas-rich spiral galaxies trigger some of the strongest starbursts known and lead to the formation of thousands of new star clusters. Whereas in ongoing mergers it is unknown at present what fraction of these clusters will remain gravitationally bound, the situation is clearer in recent, 0.5-2 Gyr old merger remnants that resemble protoellipticals. There, star clusters numbering in the few hundreds are found to have luminosities (M-V = -8 to -16), median colors (V-I = 0.5-0.7), and median half-light radii (less than or similar to 5 pc) consistent with their being young globular clusters. Evidence concerning these clusters' nature, numbers, relation to globular clusters in ellipticals, and progenitors is reviewed.