First detection of triply-deuterated methanol

• DOI: 10.1051/0004-6361:20034490
• Publication Date: 2004-02-23T09:00:24Z
• Authors: B. Parise; A. Castets; E. Herbst; E. Caux; C. Ceccarelli; I. Mukhopadhyay; A. G. G. M. Tielens
• Keywords: Isotopomers; Protostar

We report the first detection of triply-deuterated methanol, with 12 observed transitions, towards low-mass protostar IRAS 16293-2422, as well multifrequency observations 13CH3OH, used to derive column density main isotopomer CH3OH. The derived fractionation ratio [CD3OH]/[CH3OH] averaged on a 10'' beam is 1.4%. Together previous CH2DOH and CHD2OH observations, present CD3OH are consistent formation methanol grain surfaces, if atomic D/H 0.1 0.3 in accreting gas. Such high can be reached frame gas-phase chemical models including all deuterated isotopomers H3+.