Clumping in hot-star winds as function of metallicity: first theoretical predictions and implications for mass-loss diagnostics


We explore the impact of metal content on clumping in the winds of massive stars. Using numerical hydrodynamics with radiative cooling, limb darkening, and base perturbations, we simulate a wind with a fixed stellar mass and luminosity and vary the wind strength \(\bar{Q}\), which varies directly with metal content. Analysis of the radial distribution of clumping in these simulations shows that the clumping factor varies with metallicity as \(f_{cl} \simeq Z^{0.3}\), implying that observationally determined H alpha mass loss diagnostics that assume metallicity-independent clumping have overestimated by 20-30% the exponent of the mass loss rate to metallicity power law relationship.