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Astron. Astrophys. 353, 399-408 (2000)

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Linear interaction between pulsations and convection, scattering and line profiles of solar p-modes

M. Gabriel

Institut d'Astrophysique de l'Université de Liège, 5, avenue de Cointe, 4000 Liège, Belgium (gabriel@astro.ulg.ac.br)

Received 9 September 1999 / Accepted 15 October 1999


First we show that when the linear stability analysis is done taking into account the interactions between convection and pulsation, it includes the influence of scattering. However, in practice, the solutions are obtained using a simple time independent solution for the unperturbed convection. Secondly, we investigate the consequences of taking the convection spectrum into account. We find that the terms which fix the value of the peak frequency shifts and of the line widths in the power spectrum are not influenced by mode coupling in opposition to the Goldreich & Murray (1994) prediction. Other terms produce line profiles with are not rigorously Lorentzian. All these terms are present even when the interaction between convection and pulsation is ignored but indeed their value varies with the theory being used. However, new terms appear. They do not modify the eigenvalues but influence the line asymmetry. Most of them lead to mode coupling. Though they are very difficult to compute, an order of magnitude estimate suggests that these terms are very small.

Key words: Sun: oscillations – stars: oscillations

© European Southern Observatory (ESO) 2000

Online publication: December 8, 1999