accreting white dwarfs a theoretical analysis of nuclear burning

• DOI: 10.14288/1.0074134
• Publication Date: 2013-01-01
• Authors: Pillay, Samara
• Keywords: 13. Climate action; 7. Clean energy; 520

Accreting white dwarfs can exhibit a variety of thermonuclear phenomena, such as shell flashes, classical and recurrent novae, as well as Type Ia supernovae. To better understand these processes, we consider the accretion of hydrogen-rich material onto the surface of a white dwarf. Our analysis is based on a semi-analytical approach that allows the investigation of properties of nuclear burning on accreting white dwarfs. In particular, we determine steady-state solutions and evaluate the stability of these solutions. As a first step, we follow Paczyński's one-zone model and confirm his results by following his analysis independently. We extend the framework to a sophisticated multi-zone model encompassing a variety of detailed physics. We determine accretion rates that may lead to stable or to unstable burning. Regimes of stable burning may result in mass increase and potentially identify progenitors of Type Ia supernovae. Unstable burning may lead to nova-like outbursts. The identification of both burning regimes is important, as these thermonuclear events influence the chemical and dynamical evolution of the Universe.