A closure model with plumes II. Application to the stochastic excitation of stellar p modes

Amplitudes of stellar p modes result from a balance between excitation and damping processes taking place in the upper-most part of convective zones in solar-type stars and can therefore be used as a seismic diagnostic for the physical properties of these external layers. Our goal is to improve the theoretical modelling of stochastic excitation of p modes by turbulent convection. With the help of the Closure Model with Plume (CMP) developed in a companion paper, we refine the theoretical description of the excitation by the turbulent Reynolds stress term. The CMP is generalized for two-point correlation products so as to apply it to the formalism developed by Samadi & Goupil (2001). The present model gives rise to a frequency dependence of the power supplied into solar p modes which is in agreement with GOLF observations for intermediate and high frequencies. Despite an increase of the Reynolds stress term contribution due to our improved description, an additional source of excitation, identified as the entropy source term, is still necessary to reproduce the observational data. Our modelling including the entropy contribution now slightly overestimates the power and calls for further theoretical improvements. Observational data from GOLF instrument in the frequency range $\nu \in$ [2 mHz, 4.5 mHz] exhibit discrepancies at the maximum level of 25%. The main improvement is likely to come from a better physical description of the excitation by entropy fluctuations in the super-adiabatic zone.