First Detection Of CHD2OH Towards Pre-stellar Cores

The inheritance of material across the star and planet formation process is traced by deuterium fractionation.

We report here the first detection of doubly deuterated methanol towards pre-stellar cores. We study the deuterium fractionation of methanol, CH3OH, towards two starless and two pre-stellar cores. We derive a D/H ratio of 0.8-1.9% with CH2DOH in pre-stellar cores H-MM1 and L694-2, consistent with measurements in more evolved Class 0/I objects and comet 67P/Churyumov-Gerasimenko, suggesting a direct chemical link arising in the pre-stellar stage.

Furthermore, the column density ratios of CHD2OH/CH2DOH are ∼50-80%, consistently high as that towards Class 0/I objects, indicating an efficient formation mechanism of CHD2OH, possibly through H atom additions to D2CO. The CH2DOH/CH3OH and CHD2OH/CH3OH column density ratios in the two pre-stellar cores are larger than that in the two starless cores B68 and L1521E, representing an evolutionary trend of methanol deuteration in early-stage cores.

Yuxin Lin, Silvia Spezzano, Paola Caselli

Comments: accepted by A&A letter
Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2212.09543 [astro-ph.GA] (or arXiv:2212.09543v1 [astro-ph.GA] for this version)
Submission history
From: Yuxin Lin
[v1] Mon, 19 Dec 2022 15:35:50 UTC (6,725 KB)
https://arxiv.org/abs/2212.09543
Astrobiology, Astrochemistry