StarlightWinds · Mass loss in the lives and deaths of massive stars

Mass loss in the lives and deaths of massive stars

Across our Universe, the dynamics and chemical evolution of spiral galaxies like the Milky Way are primarily controlled by the lives and deaths of stars with masses many times that of the Sun. But the evolution of these massive stars is, in turn, highly regulated by the huge amounts of mass lost from their surfaces, by means of powerful starlight-driven winds. These stellar winds critically determine how such massive stars evolve through their lives, how they finally die in giant supernova explosions, and how they leave behind them exotic remnants such as neutron stars and black holes. However, due to the very large quantitative uncertainties associated with this mass loss, present-day predictions for such massive-star evolution are seriously flawed. As just one recent example of this, mass loss is currently being highlighted as a main uncertainty in massive-star progenitor models of gravitational wave sources like the ones recently observed by the advanced LIGO-detectors. The overarching goal of this ambitious project has been to fundamentally improve this situation by using novel methods to develop new models of radiation-driven winds from hot, massive stars. Using state-of-the art numerical techniques, as well as innovative analytic theory development, for the effects of light-transfer on the wind-dynamics, we have developed a new generation of drastically improved wind models from massive stars in their hydrogen core burning phase. Including critical physics ingredients lacking in earlier generations of such simulations, our new models show systematically lower mass-loss rates when compared to these earlier models, which are the current standard predictions included in calculations of the star's evolution. First results from a few observationally driven studies seem further to empirically support our lower predicted mass-loss rates, and tentative studies reducing the mass-loss rates in evolution calculations indicate significant effects on e.g. the evolution of the star's surface rotation. Spurred by this, the former fellow and his old and new collaborators are now planning several exciting spin-off scientific projects, which will build directly on the results obtained during the Marie-Curie action.

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