A&A 463, 297-308 (2007)
Excitation of solar-like oscillations across the HR diagramR. Samadi1, 2, D. Georgobiani3, R. Trampedach4, M. J. Goupil2, R. F. Stein5, and Å. Nordlund6
1 Observatório Astronómico UC, Coimbra, Portugal
2 Observatoire de Paris, LESIA, CNRS UMR 8109, 92195 Meudon, France
3 Center for Turbulence Research, Stanford University NASA Ames Research Center, Moffett Field, USA
4 Research School of Astronomy and Astrophysics, Mt. Stromlo Observatory, Cotter Road, Weston ACT 2611, Australia
5 Department of Physics and Astronomy, Michigan State University, Lansing, USA
6 Niels Bohr Institute for Astronomy Physics and Geophysics, Copenhagen, Denmark
(Received 6 September 2006 / Accepted 14 November 2006 )
Aims.We extend semi-analytical computations of excitation rates for solar oscillation modes to those of other solar-like oscillating stars to compare them with recent observations
Methods.Numerical 3D simulations of surface convective zones of several solar-type oscillating stars are used to characterize the turbulent spectra as well as to constrain the convective velocities and turbulent entropy fluctuations in the uppermost part of the convective zone of such stars. These constraints, coupled with a theoretical model for stochastic excitation, provide the rate at which energy is injected into the p-modes by turbulent convection. These energy rates are compared with those derived directly from the 3D simulations.
Results.The excitation rates obtained from the 3D simulations are systematically lower than those computed from the semi-analytical excitation model.
Key words: convection -- turbulence -- Sun: oscillations -- Hertzsprung-Russell (HR) and C-M -- stars: variables: general -- methods: numerical
© ESO 2007