`\delta \mu mixing' on the Red Giant Branch
George C. Angelou, John C. Lattanzio, Ross P. Church, Richard J. Stancliffe, David S. P. Dearborn, Graeme H. Smith, Christopher A. Tout, Verne V. Smith · Proceedings of 11th Symposium on Nuclei in the Cosmos — PoS(NIC XI) · 2011
We use observations of M3 to constrain thermohaline mixing.This is done by matching [C/Fe] and [N/Fe] along the RGB of M3.We find our models can explain observations if it is assumed there is a spread of ∼ 0.3 -0.4 dex in [C/Fe] in the stars in M3 from their birth.We reproduce the full spread in [C/Fe] at the tip of the RGB.Thermohaline mixing can produce a significant change in [N/Fe] as a function of absolute magnitude on the RGB for initially CN-weak stars, but not for initially CN-strong stars, which have so much nitrogen to begin with that any deep mixing does not significantly affect the surface nitrogen composition.