Abstract.We have calculated a grid of massive star wind models and mass-loss rates for a wide range of metal abundances between 1/100 ≤ Z/Z ≤ 10. The calculation of this grid completes the Vink et al. (2000) for stars with T eff > ∼ 25 000 K, andṀ ∝ Z 0.64 for B supergiants with T eff < ∼ 25 000 K. Although it is derived that the exponent of the mass loss vs. metallicity dependence is constant over a large range in Z, one should be aware of the presence of bi-stability jumps at specific temperatures. Here the character of the line driving changes drastically due to recombinations of dominant metal species resulting in jumps in the mass loss. We have investigated the physical origins of these jumps and have derived formulae that combine mass loss recipes for both sides of such jumps. As observations of different galaxies show that the ratio Fe/O varies with metallicity, we make a distinction between the metal abundance Z derived on the basis of iron or oxygen lines. Our mass-loss predictions are successful in explaining the observed mass-loss rates for Galactic and Small Magellanic Cloud Otype stars, as well as in predicting the observed Galactic bi-stability jump. Hence, we believe that our predictions are reliable and suggest that our mass-loss recipe be used in future evolutionary calculations of massive stars at different metal abundance. A computer routine to calculate mass loss is publicly available.

This long-awaited graduate textbook, written by two pioneers of the field, is the first to provide a comprehensive introduction to the observations, theories and consequences of stellar winds. The rates of mass loss and the wind velocities are explained from basic physical principles. This book also includes chapters clearly explaining the formation and evolution of interstellar bubbles, and the effects of mass loss on the evolution of high- and low-mass stars. Each topic is introduced simply to explain the basic processes and then developed to provide a solid foundation for understanding current research. This authoritative textbook is designed for advanced undergraduate and graduate students and researchers seeking an understanding of stellar winds and, more generally, supersonic flows from astrophysical objects. It is based on courses taught in Europe and the US over the past twenty years and includes seventy problems (with answers) for coursework or self-study.

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The formation and evolution of star cluster populations are related to the galactic environment. Cluster formation is governed by processes acting on galactic scales, and star cluster disruption is driven by the tidal field. In this paper, we present a self‐consistent model for the formation and evolution of star cluster populations, for which we combine an N‐body/smoothed particle hydrodynamics galaxy evolution code with semi‐analytical models for star cluster evolution. The model includes star formation, feedback, stellar evolution and star cluster disruption by two‐body relaxation and tidal shocks. The model is validated by a comparison to N‐body simulations of dissolving star clusters. We apply the model by simulating a suite of nine isolated disc galaxies and 24 galaxy mergers. The evolutionary histories of individual clusters in these simulations are discussed to illustrate how the environment of clusters changes in time and space. It is found that the variability of the disruption rate with time and space affects the properties of star cluster populations. In isolated disc galaxies, the mean age of the clusters increases with galactocentric radius. The combined effect of clusters escaping their dense formation sites (‘cluster migration’) and the preferential disruption of clusters residing in dense environments (‘natural selection’) implies that the mean disruption rate of the population decreases with cluster age. This affects the slope of the cluster age distribution, which becomes a function of the star formation rate density (star formation rate per unit volume). The evolutionary histories of clusters in a galaxy merger vary widely and determine which clusters survive the merger. Clusters that escape into the stellar halo experience low disruption rates, while clusters orbiting near the starburst region of a merger are disrupted on short time‐scales due to the high gas density. This impacts the age distributions and the locations of the surviving clusters at all times during a merger. The paper includes a discussion of potential improvements for the model and a brief exploration of possible applications. We conclude that accounting for the interplay between the formation, disruption and orbital histories of clusters enables a more sophisticated interpretation of observed properties of cluster populations, thereby extending the role of cluster populations as tracers of galaxy evolution.