Matteo Cantiello edited Clump.tex  about 10 years ago

Commit id: fe5883288a0f3a1ca6ab9bd772b4f4b3b7b26f2d

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In our models during the He-flash the rotational period of the core increases quite rapidly by a factor of about 10. This is because the nuclear energy released results in core expansion. In our $1.5\mso$ model the $0.46 \mso$ core expands by approximately a factor of 3 during the He-flash, with core moment of inertia increasing by a factor of 10 from $I_{\rm c}=3.13\times10^{50} \GramSc$ to $I_{\rm c}=3.06\times10^{51} \GramSc$ \citep[See also][]{Kawaler:2005}, fully accounting for the spin down observed in the models (See Fig.~\ref{period_evolution}).  Even if the timescale of the He-flash is too short for angular momentum transport outside the core, we note that the convective episodes that accompany the He flash can potentially play an important role in the redistribution of angular momentum inside the He-core.  Such rapid mixing episode can change the rotational profile of the g-mode cavity, as they lead to a fairly rigidly rotating radiative region above core He-burning. Therefore the expectation is that, regardless of previous history of angular momentum transport, clump stars that underwent ignition of He in a degenerate core should be nearly rigidly rotating.  $ 4 > <  3 $ % two effects: %Double check this.  %\begin{enumerate}  %\item The removal of the degeneracy and the release of nuclear energy result in expansion of the He core.