Fang-Chun Liu (NTNU); Friedrich Wyrowski (MPIFR); Bérengère Parise (MPIFR); Karl M. Menten (MPIFR); Qizhou Zhang (CFA), and Rolf Guesten(MPIFR)
Water is an important molecule in star-forming regions because water is the most abundant constituent of the icy mantles of dust grains, a cornerstone molecule in oxygen chemistry and an essential molecule to the proliferation of life. However, its formation mechanisms are still not very well constrained. We aim at understanding the formation pathways of water by investigating its deuterium fractionation in several star-forming regions. Using the 1-D radiative transfer code RATRAN, we obtained the HDO and H2-18O fractional abundances throughout the envelopes. Our results suggest that the sublimation is very similar in low- and high-mass star-forming regions. After comparing the [HDO]/[H2O] ratios estimated from previous studies and the ones from our work, we found that the obtained HDO fractional abundance in the low- and high-mass star-forming regions do not correlate with the physical indicators of the evolution of the star-forming regions. Furthermore, it is found that the HDO/H2O ratios in the innermost regions in the low-mass protostars, in the envelopes/outflows in the high-mass star-forming regions are very consistent, implying that the chemical evolution of water is the same regardless of the masses of the regions.