A survey has been made of 27 Galactic star-forming regions in the (CH3CN) 6
(K)-5(K), 5(K)-4(K), and 8(K)-7(K) lines of methyl cyanide (CH3CN) at 110,
92, and 147 GHz. Twenty-five sources were detected at 110 GHz, nineteen at
92 GHz, and three at 147 GHz. The strongest CH3CN emission arises in hot co
res in regions of massive star formation. The abundance of CH3CN in these o
bjects exceeds 10(-9) as a consequence of grain mantle evaporation. Weaker
CH3CN lines were found in a number of sources. These can arise in either wa
rm (30-50 K), dense (>10(4) cm(-3)) clouds or in hot regions with cooler ga
s. (C) 2000 MAIK "Nauka/Interperiodica".