Globular Cluster Systems of Massive Compact Elliptical Galaxies in the Local Universe: Evidence for Relic Red Nuggets?

Nearby massive compact elliptical galaxies (MCEGs) are strong candidates for relic (i.e. local analogs of red nuggets at high redshifts). It is expected that the globular cluster (GC) systems dominated by (metal-rich) GCs. NGC 1277 known as a unique example such galaxy in previous study. In this study, we search GCs 12 nearby MCEGs distances $\lesssim 100$ Mpc from Hubble Space Telescope/Wide Field Camera 3 F814W($I_{814}$)/F160W($H_{160}$) archival images. We find most these host rich population with color range $0.0<(I_{814}-H_{160})_0<1.1$. The fractions their $f_{RGC} =0.2$ to 0.7 mean =0.48\pm0.14$. divide MCEG sample into two groups: one clusters and other groups/fields. GC fraction $0.60\pm0.06$, which 0.2 larger than value group/field MCEGs, $0.40\pm0.10$. $\sim$0.3 giant early-type similar stellar mass Virgo ($f_{RGC} =0.33\pm0.13$). Our results show our indeed galaxies. This further implies majority formed early universe have rarely undergone mergers after they became about 10 Gyr ago.