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arXiv · 0906.3951

Theoretical amplitudes and lifetimes of non-radial solar-like oscillations in red giants

M. -A. Dupret·K. Belkacem·R. Samadi·J. Montalban·O. Moreira·A. Miglio·M. Godart·P. Ventura·H. -G. Ludwig·A. Grigahcene·M. -J Goupil·A. Noels·E. Caffau
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Abstract

Solar-like oscillations have been observed in numerous red giants from ground and from space. An important question arises: could we expect to detect non-radial modes probing the internal structure of these stars? We investigate under what physical circumstances non-radial modes could be observable in red giants; what would be their amplitudes, lifetimes and heights in the power spectrum (PS)? Using a non-radial non-adiabatic pulsation code including a non-local time-dependent treatment of convection, we compute the theoretical lifetimes of radial and non-radial modes in several red giant models. Next, using a stochastic excitation model, we compute the amplitudes of these modes and their heights in the PS. Very distinct results are found depending on the evolutionary status of the star.

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M. -A. Dupret, K. Belkacem, R. Samadi, J. Montalban, O. Moreira, A. Miglio, M. Godart, P. Ventura, H. -G. Ludwig, A. Grigahcene, M. -J Goupil, A. Noels, E. Caffau. 2009-06-22. Theoretical amplitudes and lifetimes of non-radial solar-like oscillations in red giants. https://doi.org/10.1051/0004-6361%2F200911713

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