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 using a sample of young white dwarfs 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 arcsecond2 Myr−1 is consistent with theoretical estimates of the relaxation time in the core of 47 Tucanae of about 70 Myr.
@article{arxiv.1502.01890,
title = {A Measurement of Diffusion in 47 Tucanae},
author = {Jeremy Heyl and Harvey B. Richer and Elisa Antolini and Ryan Goldsbury and Jason Kalirai and Javiera Parada and Pier-Emmanuel Tremblay},
journal= {arXiv preprint arXiv:1502.01890},
year = {2015}
}
Comments
12 pages, 10 figures, accept for publication in the Astrophysical Journal (added a short passage on blue stragglers descendants and corrected a minor typographical error in Eq. 15)