Deuterium Chemodynamics of Massive Pre-Stellar Cores

High levels of deuterium fractionation of N2H+ (i.e. $\mathrm{D^{{\mathrm{N_2H^+}}}_{\text{frac}}}$≳ 0.1) are often observed in pre-stellar cores (PSCs) and detection of N2D+ is a promising method to identify elusive massive PSCs. However, the physical and chemical conditions required to reach such high levels of deuteration are still uncertain, as is the diagnostic utility of N2H+ and N2D+ observ...