Measurement of the methyl cyanide E/A ratio in TMC-1.
We have observed the methyl cyanide (CH3CN) J = 2-1 K=0 and 1 transitions toward the cyanopolyyne peak of TMC-1 and have derived an E/A (ortho/para) abundance ratio NE/NA approximately 0.75 +/- 0.10.  The total methyl cyanide column density is Ntotal = 5 10(12) cm-2 toward TMC-1, in agreement with earlier results from the J=1-0 lines.
Minh
Y C
YC
Korea Astronomy Observatory, Whaam-dong, Yusong, Korea.
Irvine
W M
WM
Ohishi
M
M
Ishikawa
S
S
Saito
S
S
Kaifu
N
N
D000097:Acetonitriles / Q000032:analysis*; D055580:Astronomical Phenomena; D001256:Astronomy; D005118:Extraterrestrial Environment; D016011:Normal Distribution; D013057:Spectrum Analysis
D000097:Acetonitriles; C032159:acetonitrile