Reference : The underlying physical meaning of the νmax - νc relation
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/107454
The underlying physical meaning of the νmax - νc relation
English
Belkacem, K. [Institut d'Astrophysique Spatiale, CNRS, Université Paris XI, 91405, Orsay Cedex, France ; Institut d'Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 17, 4000, Liège, Belgium]
Goupil, M. J. [LESIA, UMR8109, Université Pierre et Marie Curie, Université Denis Diderot, Obs. de Paris, 92195, Meudon Cedex, France]
Dupret, Marc-Antoine mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie]
Samadi, R. [LESIA, UMR8109, Université Pierre et Marie Curie, Université Denis Diderot, Obs. de Paris, 92195, Meudon Cedex, France]
Baudin, F. [Institut d'Astrophysique Spatiale, CNRS, Université Paris XI, 91405, Orsay Cedex, France]
Noels-Grötsch, Arlette [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Département d'astrophys., géophysique et océanographie (AGO) >]
Mosser, B. [LESIA, UMR8109, Université Pierre et Marie Curie, Université Denis Diderot, Obs. de Paris, 92195, Meudon Cedex, France]
1-Jun-2011
Astronomy and Astrophysics
EDP Sciences
530
142
Yes (verified by ORBi)
International
0004-6361
1432-0746
Les Ulis
France
[en] convection ; turbulence ; stars: oscillations ; stars: interiors
[en] Asteroseismology of stars that exhibit solar-like oscillations are enjoying a growing interest with the wealth of observational results obtained with the CoRoT and Kepler missions. In this framework, scaling laws between asteroseismic quantities and stellar parameters are becoming essential tools to study a rich variety of stars. However, the physical underlying mechanisms of those scaling laws are still poorly known. Our objective is to provide a theoretical basis for the scaling between the frequency of the maximum in the power spectrum (ν[SUB]max[/SUB]) of solar-like oscillations and the cut-off frequency (ν[SUB]c[/SUB]). Using the SoHO GOLF observations together with theoretical considerations, we first confirm that the maximum of the height in oscillation power spectrum is determined by the so-called plateau of the damping rates. The physical origin of the plateau can be traced to the destabilizing effect of the Lagrangian perturbation of entropy in the upper-most layers, which becomes important when the modal period and the local thermal relaxation time-scale are comparable. Based on this analysis, we then find a linear relation between ν[SUB]max[/SUB] and ν[SUB]c[/SUB], with a coefficient that depends on the ratio of the Mach number of the exciting turbulence to the third power to the mixing-length parameter.
http://hdl.handle.net/2268/107454
10.1051/0004-6361/201116490
http://adsabs.harvard.edu/abs/2011A%26A...530A.142B
http://de.arxiv.org/abs/1104.0630

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