Jim Fuller edited WH_YIS_THIS_PARA_WIDER__.tex  almost 9 years ago

Commit id: 9025a536fb300bc1d642719cae0c760a8801c2c7

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%[WH YIS THIS PARA WIDER THAN THE REST IN THE VIEW MODE?]  In Figure 4, we show the observed \numax \numax\  and inferred mass of all the stars superimposed on a contour plot of theoretically predicted magnetic field strengths  at the hydrogen-burning shell (Fuller et al. 2015). The location of a star  with suppressed modes (filled circles) provides a lower limit to the field 

%strong the field in the core [at least] needs to be for suppression to  %be observed.  For a given \numax, \numax\,  stars more massive than 1.4\msol require increasingly strong magnetic fields to suppress their dipole modes. From Figure 4, there is no clear upper limit to the field strengths attainable in red giant cores, as suppressed stars are common even when field strengths $B> $ B>  1 \, {\rm MG}$ are required for suppression. However, the hint of a fractional decline of suppressed stars beyond 2\msol seen in Fig. 3 suggests there may be an upper limit to the stellar mass beyond which typical dynamo-generated magnetic fields can no longer cause oscillation mode suppression in intermediate-mass stars. Such an upper mass limit may be caused by the differing core structure of stars more massive than 2\msol, which evolve through the red giant phase much faster than stars of lower mass. Our results show that core-dynamo-generated fields remain stable through the red giant phase more than $10^8 \, {\rm yr}$ after the dynamo shuts off at the end of hydrogen-core burning. The occurrence rate of these long-lived core fields is much larger than the occurrence rate of strong fields observed at the surfaces of magnetic Ap stars, which may have been generated by a pre-hydrogen-core burning dynamo during star formation (***REF***). We conclude that fields generated during hydrogen-core burning are able to settle into stable equilibrium configurations much more commonly (greater than $60\%$ of the time) than fields generated during star formation (less than $10\%$ of the time).