Ospina-Zamudio, J.J.Ospina-ZamudioFavre, C.C.FavreKounkel, M.M.KounkelXu, L. -H.L. -H.XuNeill, J.J.NeillLefloch, B.B.LeflochFaure, A.A.FaureBergin, E.E.BerginFEDELE , DAVIDEDAVIDEFEDELEHartmann, L.L.Hartmann2022-06-202022-06-2020190004-6361http://hdl.handle.net/20.500.12386/32416We investigate the deuteration of methanol towards the high-mass star-forming region NGC 7538-IRS1. We carried out a multi-transition study of CH<SUB>3</SUB>OH, <SUP>13</SUP>CH<SUB>3</SUB>OH, and the deuterated flavors, CH<SUB>2</SUB>DOH and CH<SUB>3</SUB>OD, between 1.0 and 1.4 mm with the IRAM-30 m antenna. In total, 34 <SUP>13</SUP>CH<SUB>3</SUB>OH, 13 CH<SUB>2</SUB>DOH lines and 20 CH<SUB>3</SUB>OD lines spanning a wide range of upper-state energies (E<SUB>up</SUB>) were detected. From the detected transitions, we estimate that the measured D/H does not exceed 1%, with a measured CH<SUB>2</SUB>DOH/CH<SUB>3</SUB>OH and CH<SUB>3</SUB>OD/CH<SUB>3</SUB>OH of about (32 ± 8) × 10<SUP>-4</SUP> and (10 ± 4) × 10<SUP>-4</SUP>, respectively. This finding is consistent with the hypothesis of a short-timescale formation during the pre-stellar phase. We find a relative abundance CH<SUB>2</SUB>DOH/CH<SUB>3</SUB>OD ratio of 3.2 ± 1.5. This result is consistent with a statistical deuteration. We cannot exclude H/D exchanges between water and methanol if water deuteration is of the order 0.1%, as suggested by recent Herschel observations. <P />This paper is dedicated to the memory of our dear colleague, Dr. Li-Hong Xu, who recently passed away.STAMPAenArticle10.1051/0004-6361/201834948https://www.aanda.org/articles/aa/full_html/2019/07/aa34948-18/aa34948-18.html2019A&A...627A..80OFIS/05 - ASTRONOMIA E ASTROFISICA