Citation:
Feng S, Li D, Caselli P, Du F, Lin Y, ipilä O, Beuther H, Sanhueza P, Tatematsu K, Liu S Y, et al. The Chemical Structure of Young High-mass Star-forming Clumps. II. Parsec-scale CO Depletion and Deuterium Fraction of HCO$^+$. \apj. 2020;901:145.