A Measurement of Diffusion in 47 Tucanae

Authors: Heyl, Jeremy; Richer, Harvey B.; Antolini, Elisa; Goldsbury, Ryan; Kalirai, Jason; Parada, Javiera; Tremblay, Pier-Emmanuel

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.