ATOMIUM: ALMA Tracing the Origins of Molecules formIng dUst in oxygen-rich M-type stars

Over 200 molecules and 15 dust species have been detected in the interstellar medium, stellar winds, exoplanets, supernovae, active galactic nuclei etc. One of the most fundamental questions in astrophysics deals with the phase transition from simple molecules to larger gas-phase clusters and eventually dust grains. The outflows of evolved stars are the best laboratories to answer this pivotal question due to their rich chemistry and relatively simple dynamical structure. Aiming to establish the dominant physical and chemical processes in the winds of evolved stars, we have requested and were granted (in Summer 2018) with an ALMA Large Program, called ATOMIUM ‘ALMA Tracing the Origins of Molecules In dUst-forming oxygen-rich M-type stars’ (PI. L. Decin, 113 hr, valued around 3.4 million euro). The ATOMIUM project is the first ALMA Large Program which is granted in the field of stellar evolution.

I apply for funding for 2 PhD students to be part of the ATOMIUM team. The students will get the opportunity to pursue frontline research in the field of evolved stars. The aim is to establish the dominant physical and chemical processes in the winds of oxygen-rich evolved stars over a range of stellar masses, pulsation behaviours, mass-loss rates, and evolutionary phases. We want to unravel the phase transition from gas-phase to dust species, pinpoint the chemical pathways, map the morphological structure, and study the interplay between dynamical and chemical phenomena.