Excitation of stellar p-modes by turbulent convection I. Theoretical formulation

Citation
R. Samadi et Mj. Goupil, Excitation of stellar p-modes by turbulent convection I. Theoretical formulation, ASTRON ASTR, 370(1), 2001, pp. 136-146
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY AND ASTROPHYSICS
ISSN journal
0004-6361 → ACNP
Volume
370
Issue
1
Year of publication
2001
Pages
136 - 146
Database
ISI
SICI code
0004-6361(200104)370:1<136:EOSPBT>2.0.ZU;2-X
Abstract
Stochatic excitation of stellar oscillations by turbulent convection is inv estigated and an expression for the power injected into the oscillations by the turbulent convection of the outer layers is derived which takes into a ccount excitation through turbulent Reynolds stresses and turbulent entropy fluctuations. This formulation generalizes results from previous works and is built so as to enable investigations of various possible spatial and te mporal spectra of stellar turbulent convection. For the Reynolds stress con tribution and assuming tile Kolmogorov spectrum we obtain a similar formula tion to those derived by previous authors. The entropy contribution to exci tation is found to originate from the advection of the Eulerian entropy flu ctuations by the turbulent velocity field. Numerical computations in the so lar case in a companion paper indicate that the entropy source term is domi nant over the Reynold stress contribution to mode excitation, except at hig h frequencies.