The NH2D/NH3 ratio toward pre-protostellar cores around the UCHII region in IRAS 20293+3952

Abstract

The deuterium fractionation, Dfrac, has been proposed as an evolutionary indicator in pre-protostellar and protostellar cores of low-mass star-forming regions. We investigate Dfrac, with high angular resolution, in the cluster environment surrounding the UCHII region IRAS 20293+3952. We performed high angular resolution observations with the IRAM Plateau de Bure Interferometer (PdBI) of the ortho-NH2D 1_{11}-1_{01} line at 85.926 GHz and compared them with previously reported VLA NH3 data. We detected strong NH2D emission toward the pre-protostellar cores identified in NH3 and dust emission, all located in the vicinity of the UCHII region IRAS 20293+3952. We found high values of Dfrac~0.1-0.8 in all the pre-protostellar cores and low values, Dfrac<0.1, associated with young stellar objects. The high values of Dfrac in pre-protostellar cores could be indicative of evolution, although outflow interactions and UV radiation could also play a role.

5 pages, 3 figures. Accepted for publication in Astronomy and Astrophysics Letters

References in corpus (6)

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• The abundances of nitrogen-containing molecules during pre-protostellar collapse
• Star formation in a clustered environment around the UCHII region in IRAS 20293+3952
• Highly deuterated pre-stellar cores in a high-mass star formation region

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