Three transitions of methanol at 1 CM wavelength

Measurements of the J k =13 2 −13 1 E (21.471 GHz), the 4 0 −3 1 E (28.316 GHz) and the 8 2 −9 1 A − (28.970 GHz) lines of CH 3 OH with the 100-m telescope are reported; the 13 2 −13 1 E and 8 2 −9 1 A − lines have been found for the first time in astronomical sources. The 8 2 −9 1 A − line is found in emission toward the compact HII region W3 (OH). Presumably this line is produced by maser action. The 4 0 −3 1 E line is found in absorption. Toward Orion KL, these three lines appear as two blended emission features. The most intense feature is centered between 5 and 10″ south of the Hot Core region. The sizes range from less than 15″ to 20″