Quantifying the effect of AGB stellar winds on our galaxy

Stars like our Sun are destined to become large and cool Asymptotic Giant Branch (AGB) stars as they age, and lose a large fraction of their mass through a stellar wind. This wind provides much of the gas and dust in the interstellar medium, which provides the building blocks for new generations of stars and planets and hence plays a vital role in the evolution of galaxies. However, many aspects of the AGB wind are still uncertain: how it forms, how it varies with time and type of AGB star, and the total mass of dust and gas it expels into the galaxy.
Working towards a complete understanding of AGB winds, this project will tackle these uncertainties in two ways, taking advantage of two state-of-the-art observational projects I am involved in. First, a large statistically representative sample of AGB stars will provide an overall view of the gas and dust in their winds, and how it varies for different types of star. Second, more detailed and sensitive observations of individual AGB stars will allow us to probe the formation of the wind close to the star, as well as variations in temperature, density, and chemistry throughout the wind. I will combine all this data to derive the physical and chemical conditions in AGB winds and determine how the population of AGB stars affects the galaxy.