Calculations of the outflow velocity of envelopes of cool giants.

摘要: We study the transfer of momentum from photons to dust grains (molecular) gas in outflow around cool giants (carbon-stars, Mira variables and OH/IR stars) beyond radius where condense. The problem is circular: radiation pressure determines velocity thus also density; on other hand density determines, via radiative effects, spectrum effective pressure. This circular solved by a rapidly converging iterative procedure. compare our predictions with observed properties large sample stars Miras find good qualitative quantitative agreement. confirm conclusion Wood et al. (1993) that very luminous Large Magellanic Cloud (LMC) owe their low dust-to-gas ratio, consequence metallicity LMC. Similarly we consider about 100 within 200 pc galactic center has an average asymptotic giant branch (AGB) luminosity uncommonly high value v(sub out); conclude these are probably metal rich, perhaps even more than Baade window studied Rich (1990).