Moment 0 map of the HOCH 2 CN 36 4,32 -35 4,31 , E up = 324 K line towards IRAS 16293B. The line is integrated over 8 velocity bins, centered on the peak frequency of the line. The positions of the half-beam and full-beam offset positions around IRAS 16293B are indicated and the beam size (0 . 5×0 . 5) is visualised in the bottom left corner. Dust continuum contours are given by the black dotted line at the levels of 0.02, 0.05, 0.1, 0.2, 0.5 Jy Beam −1 .

Moment 0 map of the HOCH 2 CN 36 4,32 -35 4,31 , E up = 324 K line towards IRAS 16293B. The line is integrated over 8 velocity bins, centered on the peak frequency of the line. The positions of the half-beam and full-beam offset positions around IRAS 16293B are indicated and the beam size (0 . 5×0 . 5) is visualised in the bottom left corner. Dust continuum contours are given by the black dotted line at the levels of 0.02, 0.05, 0.1, 0.2, 0.5 Jy Beam −1 .

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Methyl isocyanate (CH$_{3}$NCO) and glycolonitrile (HOCH$_{2}$CN) are isomers and prebiotic molecules that are involved in the formation of peptide structures and the nucleobase adenine, respectively. ALMA observations of the intermediate-mass Class 0 protostar Serpens SMM1-a and ALMA-PILS data of the low-mass Class 0 protostar IRAS~16293B are used...

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Context 1
... 2 CN lines are not clearly observed, as the baseline at these positions dips. Furthermore, some transitions seem to be better reproduced with low excitation temperatures, whereas others require warmer temperatures. This could indicate that two gas components are traced, as also shown by Zeng et al. (2019) At the half-beam offset position (see Fig. 3), which is closer to the continuum peak of IRAS 16293B, HOCH 2 CN can be identified. At this position, at least four a-type transitions are clearly detected, while the three other lines suffer from line blending or absorption features, see Fig. 7. These lines can approximately be fitted with synthetic spectra of N T = 3.0×10 15 cm −2 ...
Context 2
... Fig. 3 Because the chemical inventory at the full-beam offset position of the PILS data is best characterised, the tentative detection of HOCH 2 CN towards this position, with a column density of ∼1.0×10 15 cm −2 ), is used for further analysis in this paper. However, the identification of HOCH 2 CN towards the half-beam offset position in ...