THE DISTRIBUTION OF DEUTERATED FORMALDEHYDE WITHIN ORION-KL

• Published in: The Astrophysical journal Vol. 808; no. 2; pp. 1 - 9
• Main Authors: Favre, Cécile, Bergin, Edwin A., Neill, Justin L., Crockett, Nathan R., Zhang, Qizhou, Lis, Dariusz C.
• Format: Journal Article
• Language: English
• Published: United States The American Astronomical Society 01-08-2015; American Astronomical Society
• Subjects: Arrays; astrochemistry; Astrophysics; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CONVERSION; COSMIC GASES; Deuteration; DEUTERIUM COMPOUNDS; EMISSION; FORMALDEHYDE; ISM: abundances; ISM: individual objects (Orion-KL); ISM: molecules; line: identification; Mantles; METHANOL; Methyl alcohol; MOLECULES; RESOLUTION; Sciences of the Universe; SPATIAL DISTRIBUTION; STARS; SURFACES
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.1088/0004-637X/808/2/155

ABSTRACT We report the first high angular resolution imaging (3 4 × 3 0) of deuterated formaldehyde (HDCO) toward Orion-KL, carried out with the Submillimeter Array. We find that the spatial distribution of the formaldehyde emission systematically differs from that of methanol: while methanol is found toward the inner part of the region, HDCO is found in colder gas that wraps around the methanol emission on four sides. The HDCO/H2CO ratios are determined to be 0.003-0.009 within the region, up to an order of magnitude higher than the D/H measured for methanol. These findings strengthen the previously suggested hypothesis that there are differences in the chemical pathways leading to HDCO (via deuterated gas-phase chemistry) and deuterated methanol (through conversion of formaldehyde into methanol on the surface of icy grain mantles).