3-Gyr-old Globular Clusters in the Merger Remnant NGC 1316: Implications for the Fate of Globular Clusters Formed During Gas-rich Galaxy Mergers

The giant early-type merger remnant galaxy NGC 1316 is an ideal probe for studying the long-term effects of a major merger on its globular cluster (GC) system, given its spectroscopically derived merger age of 3 Gyr which we reported in a recent paper. Here we report several pieces of photometric evidence showing that the second-generation GCs in NGC 1316 are at an evolutionary phase in between that of luminous GCs found in younger merger remnants such as (e.g.) NGC 7252 and that of red' GCs found in normal, old’ ellipticals. The observation that massive, second-generation GCs formed during major mergers can survive for at least 3 Gyr provides strong evidence that these clusters can have normal' mass functions including low-mass stars, and hence that they can survive to reach old age’ similar to those of `normal’ ellipticals.