Exploring Nucleosynthesis in Accreting Neutron Star Common Envelopes

This project explores nucleosynthesis in common envelope accreting binary systems which contains a neutron star and a companion star. When the companion star undergoes its RGB phase, it is possible that the envelope of the companion star covers the neutron star. This allows the neutron star to accrete material from the companion's envelope and an accretion disk is thought to form around the neutron star.

In particular, the nucleosynthesis which occurs within the accretion disk is of great interest. For example, it is thought that the rp-process may occur within these systems, which would help to explain the existence of proton rich nuclei which cannot be produced at other astrophysical sites.

In order to understand the nucleosynthesis within the accretion disk, I will in particular study how the accreted material moves on and off of the neutron star; how the newly accreted material mixes with material which has already undergone nucleosynthesis; as well as the impact of accreting neutron star common envelope systems on galactic chemical evolution (GCE). We will also explore how much of the material synthesised in the accretion disk reaches the companion star's envelope, as well as how much of that material then reaches the interstellar medium (ISM) when the companion star goes through its supernova phase or expels its envelope. If this site does allow the rp-process to occur then the proton rich products may be able to reach the ISM and impact GCE. We will explore these processes jointly with our collaborators at the University of Victoria (Canada) and Los Alamos National Laboratory (USA).