TY - JOUR

T1 - Torsional-rotational spectrum of doubly deuterated dimethyl ether (CH3OCHD2)

T2 - First ALMA detection in the interstellar medium

AU - Richard, C.

AU - Jorgensen, J. K.

AU - Margules, L.

AU - Motiyenko, R. A.

AU - Guillemin, J. -C.

AU - Groner, P.

PY - 2021/7/28

Y1 - 2021/7/28

N2 - Context. In 2013, we published the first rotational analysis and detection of mono-deuterated dimethyl ether in the solar-type protostar IRAS 16293-2422 with the IRAM 30 m telescope. Dimethyl ether is one of the most abundant complex organic molecules in star-forming regions, and its D-to-H (D/H) ratios are important to understand its chemistry and trace the source history.Aims. We present the first analysis of doubly deuterated dimethyl ether (methoxy-d(2)-methane, 1,1-dideuteromethylether) in its ground-vibrational state, based on an effective Hamiltonian for an asymmetric rotor molecule with internal rotors. The analysis covers the frequency range 0.15-1.5 THz.Methods. The laboratory rotational spectrum of this species was measured between 150 and 1500 GHz with Lille's submillimeter spectrometer. For the astronomical detection, we used the Atacama Large Millimeter/submillimeter Array observations from the Protostellar Interferometric Line Survey.Results. New sets of spectroscopic parameters have been determined by a least squares fit with the ERHAM code for both symmetric and asymmetric conformers. As for the mono-deuterated species, these parameters have permitted the first identification in space of both conformers of a doubly deuterated dimethyl ether via detection near the B component of the Class 0 protostar IRAS 16293-2422.

AB - Context. In 2013, we published the first rotational analysis and detection of mono-deuterated dimethyl ether in the solar-type protostar IRAS 16293-2422 with the IRAM 30 m telescope. Dimethyl ether is one of the most abundant complex organic molecules in star-forming regions, and its D-to-H (D/H) ratios are important to understand its chemistry and trace the source history.Aims. We present the first analysis of doubly deuterated dimethyl ether (methoxy-d(2)-methane, 1,1-dideuteromethylether) in its ground-vibrational state, based on an effective Hamiltonian for an asymmetric rotor molecule with internal rotors. The analysis covers the frequency range 0.15-1.5 THz.Methods. The laboratory rotational spectrum of this species was measured between 150 and 1500 GHz with Lille's submillimeter spectrometer. For the astronomical detection, we used the Atacama Large Millimeter/submillimeter Array observations from the Protostellar Interferometric Line Survey.Results. New sets of spectroscopic parameters have been determined by a least squares fit with the ERHAM code for both symmetric and asymmetric conformers. As for the mono-deuterated species, these parameters have permitted the first identification in space of both conformers of a doubly deuterated dimethyl ether via detection near the B component of the Class 0 protostar IRAS 16293-2422.

KW - molecular data

KW - submillimeter: ISM

KW - ISM: molecules

KW - astrochemistry

KW - MICROWAVE-SPECTRA

KW - MOLECULES

KW - SPECTROSCOPY

KW - FORMALDEHYDE

KW - ABUNDANCE

KW - METHANOL

KW - STATES

U2 - 10.1051/0004-6361/202141282

DO - 10.1051/0004-6361/202141282

M3 - Journal article

VL - 651

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

M1 - A120

ER -