Deuterium in L1688 cold dense cores

We study how the deuterium fraction (RD) changes with environment, compare deuteration of ions and neutrals, core centre and its envelope, and attempt to reproduce the observed results with a gas-grain chemical model. We chose high and low gas density tracers to study both core centre and the envelope.

With the IRAM 30 m antenna, we mapped N_2_H+(1-0), N_2_D+(1-0), H^13^CO+ (1-0) and (2-1), DCO+(2-1), and p-NH_2_D(111-101) towards the chosen cores. The missing p-NH3 and N_2_H+(1-0) data were taken from the literature. To measure the molecular hydrogen column density, dust and gas temperature within the cores, we used the Herschel/SPIRE dust continuum emission data, the Green Bank Ammonia Survey data (NH3), and the COMPLETE survey data to estimate the upper limit on CO depletion.