OH Satellite Line Masers and an Active Galactic Nucleus Candidate in M82

We report the detection of OH satellite line masers at 1720 MHz and 1612 MHzfrom the nuclear region of the starburst galaxy M82. The observations wereaimed at detecting 1720 MHz maser emission from the known radio emitting SNR inthe nuclear region. At 1720 MHz we detect six features above the 5-sigma limitset by noise, four in emission and two in absorption. Three of the emissionfeatures appear closely associated with known discrete continuum radio sources,and one of the absorption features is precisely coincident with the discretecontinuum source 44.01+59.6. The latter source also exhibits strong 1612 MHzemission at the same velocity. No other 1612 MHz features were detected. All ofthe 1720 MHz emission features are consistent with masers pumped by collisionswith molecular hydrogen at densities between 10^3 cm^{-3} and 10^5 cm^{-3}, andT_k between 50 K and 250 K. The absorption and emission associated with the twosatellite lines in 44.01+59.6, together with other evidence, points to thepossibility that this source is the AGN in M82.Comment: accepted ApJ