The SLUGGS survey: globular cluster kinematics in a ‘double sigma’ galaxy – NGC 4473

摘要: NGC 4473 is a so--called double sigma (2$\sigma$) galaxy, i.e. galaxy with rare, peaks in its 2D stellar velocity dispersion. Here, we present the globular cluster (GC) kinematics out to $\sim10\,R_e$ (effective radii) using data from combined HST/ACS and Subaru/Suprime--Cam imaging Keck/DEIMOS spectroscopy. We find that 2$\sigma$ nature of persists up 3 $R_e$, though it becomes misaligned photometric major axis. also observe significant offset between GC rotation amplitudes. This can be understood as co--addition counter--rotating stars producing little net rotation. identify sharp radial transition at $\sim4\,R_e$ suggesting well defined kinematically distinct halo. In inner region ($ 4\,R_e$), red GCs rotate an opposite direction compared GCs, along axis, while blue axis intermediate minor axes. population very elevated amplitude The multiple kinematic components highlight complex formation evolutionary history this outer components.