Effects of localized horizontal flow patterns on eigenfrequencies of stellar global modes

Serbian Astronomical Journal

Čadež V.M.¹  Vanlommel P.² 

[1] Astronomical Observatory, Belgrade;Royal Observatory of Belgium, Brussels, Belgium;

关键词: Sun: helioseismology;    stars: oscillations;   

DOI  :  10.2298/SAJ0571019C

来源: DOAJ

【 摘 要 】

The main goal of this paper is to estimate the significance of effects the flow profile U0(z) induces on computed global oscillation spectra. We solve numerically the eigenvalue problem for the described basic state configuration with reference to solar conditions as an example of a typical star. Obtained results show that the considered shear flows do not only affect the eigenfrequencies ω but they also have an impact on spatial profiles of eigensolutions of linearized physical quantities. Such flows may even allow for local amplification of perturbation amplitudes at positions where the resonant Doppler condition ω = kU0(z) is satisfied. For typical subsonic flow speeds this Doppler resonant wave amplification can be effective only in the case of the non acoustic gravity modes with sufficiently large horizontal wave numbers k.

【 授权许可】

Unknown