A Measurement of Diffusion in 47 Tucanae
Richer, Harvey B.; Heyl, Jeremy; Kalirai, Jason; Tremblay, Pier-Emmanuel; Goldsbury, Ryan; Parada, Javiera; Antolini, Elisa
Canada, Italy, United States
Abstract
Using images from the Hubble Space Telescope Wide-Field Camera 3, we measure the rate of diffusion of stars through the core of the globular cluster 47 Tucanae (47 Tuc) using a sample of young white dwarfs that were identified in these observations. This is the first direct measurement of diffusion due to gravitational relaxation. We find that the diffusion rate κ ≈ 10-13 arcsec2 Myr-1 is consistent with theoretical estimates of the relaxation time in the core of 47 Tuc of about 70 Myr.