Acoustic wave energy fluxes for late-type stars - II. Nonsolar metallicities

Using the Lighthill-Stein theory with modifications described by Musielak e t al. (1994), the acoustic wave energy fluxes were computed for late-type s tars with the solar metal abundance (population I stars) by Ulmschneider et al. (1996). We now extend these computations to stars with considerably lo wer metal content (population II stars with 1/10 to 1/1000 of solar metalli city) and find that the acoustic fluxes calculated for stars of different s pectral types and different luminosities are affected differently by the me tallicity. It is found that the Hertzsprung-Russel diagram can be subdivide d into three domains (labeled I, II and III) representing a different depen dence of the generated acoustic fluxes on the stellar metal abundance. For the high T-eff stars of domain I there is no dependence of the generated ac oustic fluxes on metallicity. In domain III are stars with low T-eff. Here the generated acoustic fluxes are lowered roughly by an order of magnitude for every decrease of the metal content by an order of magnitude. Finally, domain II represents the transition between the other two domains and the g enerated acoustic fluxes strongly depend on T-eff. The boundaries between t he domains I and II, and II and III can be defined by simple relationships between stellar effective temperatures and gravities.