The ALMA-PILS survey: First detections of deuterated formamide and deuterated isocyanic acid in the interstellar medium
Journal article, 2016

Formamide (NH2CHO) has previously been detected in several star-forming regions and is thought to be a precursor for different prebiotic molecules. Its formation mechanism is still debated, however. Observations of formamide, related species, and their isopotologues may provide useful clues to the chemical pathways leading to their formation. The Protostellar Interferometric Line Survey (PILS) represents an unbiased, high angular resolution and sensitivity spectral survey of the low-mass protostellar binary IRAS 16293-2422 with the Atacama Large Millimeter/submillimeter Array (ALMA). For the first time, we detect the three singly deuterated forms of NH2CHO (NH2CDO, cis-and trans-NHDCHO), as well as DNCO towards the component B of this binary source. The images reveal that the different isotopologues are all present in the same region. Based on observations of the 13C isotopologues of formamide and a standard 12C/13C ratio, the deuterium fractionation is found to be similar for the three different forms with a value of about 2%. The DNCO/HNCO ratio is also comparable to the D/H ratio of formamide (~1%). These results are in agreement with the hypothesis that NH2CHO and HNCO are chemically related through grain-surface formation.

Stars: formation

Stars: protostars


ISM: molecules


ISM: individual objects: IRAS 16293-2422


A. Coutens

University College London (UCL)

J. K. Jorgensen

University of Copenhagen

M. H. D. van der Wiel

University of Copenhagen

H. S. P. Müller

University of Cologne

J. M. Lykke

University of Copenhagen

Per Bjerkeli

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

T. L. Bourke

SKA Organisation

H. Calcutt

University of Copenhagen

M. N. Drozdovskaya

Leiden University

C. Favre

Centre national de la recherche scientifique (CNRS)

E. C. Fayolle

Harvard-Smithsonian Center for Astrophysics

R. T. Garrod

University of Virginia

S. K. Jacobsen

University of Copenhagen

N. F W Ligterink

Leiden University

K. I. Öberg

Harvard-Smithsonian Center for Astrophysics

M. V. Persson

Leiden University

E. F. van Dishoeck

Leiden University

Max Planck Institute

S. F. Wampfler

University of Copenhagen

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 590 Art. no. L6-

Subject Categories

Astronomy, Astrophysics and Cosmology


Basic sciences



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9/7/2018 1