Modelling of deuterated methanol formation around Class 0 objects
Abstract
Deuterated methanol is found around Class 0 objects of all mass ranges. Although various deuterated species are reported, methanol (CH3OH) is of special interest, because it is the simplest complex organic molecule and the majority of the possible deuterated isotopologues have been observed. Furthermore, it is one of the most common molecules in prestellar cores and thus an important precursor of chemical complexity. Observations have illustrated that deuterated species in general are widespread in star-forming regions, but the origin of their various ratios is not known. This is also true for deuterated methanol. The observed ratios not only differ from predicted ratios, but there is also a clear observed difference between low- and high-mass protostars. It is believed that methanol is formed by subsequent addition of hydrogen atoms to adsorbed CO molecules on dust grain surfaces, but laboratory experiments have shown that (excited) atomic oxygen insertion into methane also leads to the formation of (deuterated) methanol. A combined modelling approach is presented, which links a physical model that couples transport of collapsing material and radiative transfer to a chemical network, that focuses on the formation of deuterated methanol around Class 0 objects and their forming protoplanetary disks. The newly proposed formation pathways are accounted for. The work aims to understand the observed ratios of deuterated methanol isotopologues from the perspective of sophisticated theoretical models.
- Publication:
-
From Stars to Planets II - Connecting our understanding of star and planet formation
- Pub Date:
- June 2019
- Bibcode:
- 2019fstp.confE...2K