Grain growth and destruction in novae

Abstract

We investigate the effects of carbon and hydrogen ionization on grain growth and destruction in novae. Grain charge effects are shown to play a significant role in terminating grain growth and initiating destruction concurrently with the ionization of hydrogen. Grain surface reactions may be an important destructive process, particularly in regions of high density. Hydrogen atoms and hydrocarbon surface groups on carbon grains should lead to infrared features, the observation of which would confirm the presence of hydrogenated carbon grains in circumnova outflows.