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A MEASUREMENT OF DIFFUSION IN 47 TUCANAE

2015; IOP Publishing; Volume: 804; Issue: 1 Linguagem: Inglês

10.1088/0004-637x/804/1/53

1538-4357

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

Astronomy and Astrophysical Research

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 $\kappa\approx 10-13$ arcsecond$^2$ Myr$^{-1}$ is consistent with theoretical estimates of the relaxation time in the core of 47 Tucanae of about 70 Myr.