LAUSR

Ancient globular clusters contain multiple stellar populations identified by variations in light element (e.g., C, N, O, Na). Though many scenarios have been suggested to explain this phenomenon, all are faced with challenges when compared with all the observational evidence. In this Letter, we propose a new scenario in which light element variations are determined by nucleosynthesis in accretion discs around black holes. Since the black holes form after a few Myrs, the cluster is expected to still be embedded in a gas rich environment. By using a simplified accretion model which assumes virial temperatures, we show that the correct light element anti-correlations could be produced in accretion flows around stellar-mass black holes. Assuming a Kroupa IMF, each black hole would only have to process ${\approx}300M_{\odot}$ of material in order to produce multiple populations; over a period of 1Myr this corresponds $ \sim10^{-4} M_{\odot}yr^{-1}$, which is within the range of values typically assumed for the formation of massive stars.