S316p.18 — Dark Matter Content in Three Galactic Globular Clusters – 47 Tuc, NGC 1851, and M 15

Date & Time

Aug 10th at 6:00 PM until 7:30 PM




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Author(s): Joowon Lee2, Jihye Shin1, Sungsoo S. Kim2

Institution(s): 1. Kavli Institute for Astronomy and Astrophysics, 2. Kyung Hee University

Globular clusters (GCs) are known to have a very small amount of or no dark matter (DM). Even if GCs are formed in individual DM halos, they must have lost the majority of the DM through dynamical processes such as mass segregation and tidal shocks. NGC 2419 and NGC 6397 did not show any evidence of significant amounts of DM, however, similar studies for other galactic GCs would be needed to understand the GC formation. Using Fokker-Planck (FP) calculations, we investigate the dynamical evolution of the Galactic GCs initially residing in mini DM halos. We trace the amount of DM of 47 Tuc, NGC 1851, and M15, which are a ‘disk/bulge’ cluster, an ‘old halo’ cluster, and a ‘young halo’ cluster, respectively. We find that the three GCs must have initially had insignificant amounts of DM, less than 20 percent of the initial stellar mass of each cluster.