The ( J,K ) = ( 1,1 ) , ( 2,2 ) , ( 3,3 ) , and ( 4,4 ) inversion lines of ammonia ( NH _ { 3 } ) have been detected toward the nuclear 40 ^ { \prime \prime } sized bar of the nearby spiral galaxy Maffei 2 .
The relative intensities of the ammonia lines are characterized by a rotational temperature of 85 K. This is higher than rotational temperatures measured toward IC 342 and most Galactic Center clouds , implying kinetic temperatures \ga 100 K. Since the kinetic temperature of the gas is larger than that of the dust , NH _ { 3 } is tracing a particularly dense warm gas component that is heated by young massive stars , cloud-cloud collisions , or ion-slip heating in the nuclear starburst .
The gas north of the nucleus ( V _ { LSR } = –80 { km s } ^ { -1 } ) is more highly excited than the gas further south ( +6 { km s } ^ { -1 } ) .
This asymmetry might be related to pronounced morphological distortions that are observed in the north-eastern part of the galaxy .