Modelling complex organic molecules in dense regions: Eley-Rideal and complex induced reaction

Recent observations have revealed the existence of complex organic molecules (COMs) in cold dense cores and pre-stellar cores. The presence of these molecules in such cold conditions is not well understood and remains a matter of debate since the previously proposed 'warm-up' scenario cannot explain these observations. In this paper, we study the effect of Eley-Rideal and complex induced reaction mechanisms of gas-phase carbon atoms with the main ice components of dust grains on the formation of COMs in cold and dense regions. Based on recent experiments, we use a low value for the chemical desorption efficiency (which was previously invoked to explain the observed COM abundances). We show that our introduced mechanisms are efficient enough to produce a large amount of COMs in the gas phase at temperatures as low as 10 K.