Stellar-model-independent measurements of γ Doradus and SPB internal rotation from gravity oscillation modes.

Owing to the unprecedented quality and long baseline of Kepler photometry, we are finally in a good position to apply asteroseismology to γ Doradus (γ Dor) and Slowly Pulsating B-type (SPB) stars. These intermediate-mass stars pulsate in high radial order gravity modes that probe the deep radiative layers near their convective-core. They are also moderate to fast rotators for which an appropriate treatment of the pulsation-rotation coupling is required to disentangle the oscillation spectrum. On the basis of the traditional approximation of rotation (TAR), we have developed a new stellar-model-independent method to simultaneously estimate the near-core rotation frequency ν_{rot}, the so-called buoyancy radius P_0, and identify the gravity modes. We construct its validity and evaluate its performance on a synthetic spectrum computed from a rotating CESTAM model of a representative γ Dor star. Due to the shortcomings of the asymptotic TAR, we find a slight bias on our estimates of ν_{rot} and P_0 but we achieve a reasonably good accuracy overall (≲ 6%). Finally, we measure the near-core rotation rates in 30 Kepler γ Dor stars and compare them with those obtained by another existing method.