1. Amplitudes of solar-like oscillations in red giants: Departures from the quasi-adiabatic approximation.
- Author
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Samadi, R., Belkacem, K., Dupret, M.-A., Goupil, M.J., Ludwig, H.-G., Barban, C., Baudin, F., and Caffau, E.
- Subjects
RED giants ,OSCILLATIONS ,PHYSICS ,VELOCITY - Abstract
CoRoT and Kepler measurements reveal us that the amplitudes of solar-like oscillations detected in red giant stars scale from stars to stars in a characteristic way. This observed scaling relation is not yet fully understood but constitutes potentially a powerful diagnostic about mode physics. Quasi-adiabatic theoretical scaling relations in terms of mode amplitudes result in systematic and large differences with the measurements performed for red giant stars. The use of a non-adiabatic intensityvelocity relation derived from a non-adiabatic pulsation code significantly reduces the discrepancy with the CoRoT measurements. The origin of the remaining difference is still unknown. Departure from adiabatic eigenfunction is a very likely explanation that is investigated in the present work using a 3D hydrodynamical model of the surface layers of a representative red giant star. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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