We have examined methanol emission from Orion KL with of the Herschel /HIFI instrument , and detected two methanol bands centered at 524 GHz and 1061 GHz .
The 524 GHz methanol band ( observed in HIFI band 1a ) is dominated by the isolated \Delta J = 0 , K = -4 \rightarrow -3 , v _ { t } = 0 Q branch , and includes 25 E-type and 2 A-type transitions .
The 1061 GHz methanol band ( observed in HIFI band 4b ) is dominated by the \Delta J = 0 , K = 7 \rightarrow 6 , v _ { t } = 0 Q branch transitions which are mostly blended .
We have used the isolated E-type v _ { t } = 0 methanol transitions to explore the physical conditions in the molecular gas .
With HIFI ’ s high velocity resolution , the methanol emission contributed by different spatial components along the line of sight toward Orion KL ( hot core , low velocity flow , and compact ridge ) can be distinguished and studied separately .
The isolated transitions detected in these bands cover a broad energy range ( upper state energy ranging from 80 K to 900 K ) , which provides a unique probe of the thermal structure in each spatial component .
The observations further show that the compact ridge is externally heated .
These observations demonstrate the power of methanol lines as probes of the physical conditions in warm regions in close proximity to young stars .