Generation of longitudinal flux tube waves in theoretical main-sequence stars: effects of model parameters

Abstract

Aims. We compute the wave energy fluxes carried by longitudinal tube waves along vertically oriented thin magnetic fluxes tubes embedded in the atmospheres of theoretical main-sequence stars based on stellar parameters deduced by Kurucz and Gray. In addition, we present a fitting formula for the wave energy flux based on the governing stellar and magnetic parameters. Methods. A modified theory of turbulence generation based on the mixing-length concept is combined with the magnetohydrodynamic equations to numerically account for the wave energies generated at the base of magnetic flux tubes. Results. The results indicate a stiff dependence of the generated wave energy on the stellar and magnetic parameters in principal agreement with previous studies. The wave energy flux F-LTW decreases by about a factor of 1.7 between G0 V and K0 V stars, but drops by almost two orders of magnitude between K0 V and M0 V stars. In addition, the values for F-LTW are significantly higher for lower in-tube magnetic field strengths. Both results are consistent with the findings from previous studies. Conclusions. Our study complements existing descriptions of magnetic energy generation in late-type main-sequence stars. Our results will be helpful for calculating theoretical atmospheric models for stars of different levels of magnetic activity.