Dominique Meyer

Non-thermal radio supernova remnants of runaway massive stars.

Stars more massive than our Sun, by at least a factor of ten, are rare but seminal objects in galaxies such as our Milky Way. Their powerful radiation, stellar winds, and explosive deaths are dominant engines driving the cycle of matter in the interstellar medium, by ionizing and chemically enriching it, inducing turbulence, and producing cosmic rays. Additionally, a significant fraction of them are ejected from their parent cluster and run supersonically through the interstellar medium. The direct surroundings of massive stars (circumstellar medium) appear as gaseous bow shock nebulae visible accross the electromagnetic spectrum. The shapes of the nebulae and their physical characteristics are the fingerprints onto the ambient medium of their past stellar evolution. Later, when massive stars die, the explosion takes place into the circumstellar medium of their progenitor, which participate in shaping the subsequent supernova remnants. However, to understand the shaping of supernova remnants, sophisticated multi-dimensional magneto-hydrodynamical and radiative transfer numerical simulations are required. In this talk, we will take a journey throughout the lives of massive stars, from their evolved to defunct evolutionary phases. We will employ state-of-art numerical models to discover how the morphology of the interstellar medium is sculptured by massive stars and what does it tell us about the stellar feedback in galaxies. Particularly, we will (i) present simulations I have tailored to the surroundings of evolved massive stars like the red supergiant Betelgeuse, to constrain its past evolution. Finally, we will (ii) explore what the asymmetries in non-thermal remnants left behind massive stars which died in a supernova explosion, like the Cygnus Loop nebula, tell us about their past lives. These elaborated simulations provide us with accurate predictive synthetic images and precise forecast confirmed by observations, that are insights into the fascinating circumstellar medium of massive stars.