Mass-loss from evolved massive stars
Thesis Supervisor: Peter Scicluna
Massive stars play an important role in enriching the interstellar medium with new elements when they explode as supernovae. However, the final stages of their evolution are strongly impacted by their mass loss and whether they have a companion, which can alter when they explode and as what kind of supernova. For many of these stars, the majority of the mass loss occurs while the stars are in the red supergiant phase. To characterise these processes, we have observed a sample of red supergiants at high contrast with SPHERE in the near infrared and optical. You will analyse these data, looking for both extended emission in scattered light (which traces dust in the outflow) and point-like sources (which may indicate companions). You will compare detections in scattered light to mass-loss rates derived from fitting the SED with dust radiative-transfer models and place limits on the distribution of companions. You will analyse sub-mm observations of CO lines from the JCMT, APEX and ALMA to determine gas mass-loss rates, which will provide the total mass loss for comparison to the dust observations. Using this dataset, you will explore the properties of the outflows and how they are related to the properties of the stars, probing the evolution of mass-loss in red supergiants.