On the Generation of Flux‐Tube Waves in Stellar Convection Zones. IV. Longitudinal Wave Energy Spectra and Fluxes for Stars with Nonsolar Metallicities

In the previous papers of this series, we developed an analytical method describing the generation of longitudinal tube waves in stellar convection zones and used it to compute the wave energy spectra and fluxes for late-type stars with the solar metal abundance (Population I). We now extend these calculations to Population II stars with effective temperatures ranging from Teff = 2500 to 10,000 K, gravities log g = 3-5, and with three different metal abundances: 1/10, 1/100, and 1/1000 of solar metallicity. The obtained results are valid for a single magnetic flux, and they show that the effects of metallicity are important only for cool stars with Teff < 6000 K and that the amount of the generated wave energy decreases roughly by an order of magnitude for every decrease of the metallicity by an order of magnitude. The maximum wave energy flux generated in Population II stars is 7 × 108 ergs cm-2 s-1, and it is practically the same for stars of different gravities and metallicities. The computed spectra and fluxes can be used to construct theoretical models of magnetic regions in chromospheres of Population II stars.