Cyanide and isocyanide abundances in the cold, dark cloud TMC-1.

摘要: We have observed emission from HCN, H/sup 13/CN, HC/sup 15/N, HN/sup 13/C, 15/NC, HC/sub 3/N, CH/sub 3/CN, and possibly 3/NC, determined an upper limit for NH/sub 2/CN, toward the cold, dark cloud TMC-1. The abundance ratio (HNC)/(HCN) = 1.55 +- 0.16 is at least a factor approx.4 approx.100 greater than that giant molecular clouds DR 21(OH) Orion KL, respectively. In contrast, corresponding methylated isomers we obtain (CH/sub 3/NC)/(CH/sub 3/CN)< or approx. =0.1. also find (NH/sub 2/CN)/(CH/sub =0.1 (HC/sub 3/N)/(CH/sub 3/CN) 30 10. no evidence anomalous hyperfine ratios indicating HCN (cf. recent work of Walmsley et al.) are result self-absorption by cold foreground gas.