Talk abstract details

Solar gravity modes are mainly trapped inside the radiative region and are then able to provide information on the properties of the central part of the Sun. However, because of their evanescent nature in the outer convective region, their photospheric amplitude (where seismic measurements are made) are expected to be very low. Their detection is thus quite challenging and has been attempted for more than 30 years. Since the mode surface velocity results from a balance between the efficiency of the excitation and the damping rates, we investigate the stochastic excitation of gravity modes by turbulent convection as well as their damping rates. We explore the low frequency domain ($\nu \in [20; 120] \mu$Hz) which, as we will explain, is more favorable to a reliable theoretical estimation of the gravity-mode amplitudes. We find that the maximum velocity is obtained for the $\ell=1$ mode with a value of few millimeters, that is order of magnitudes higher than previous works. From those results, the delectability threshold of those modes will be discussed.