Detection of a 6.7 GHz methanol kilomaser toward NGC4945
  We report the detection of emission from the 6.7 GHz 5(1)-6(0)A+ transition
of methanol towards the center of the nearby galaxy NGC4945. This is the first
detection of emission in this transition beyond the local group. The isotropic
luminosity of the integrated 6.7 GHz methanol emission is approximately a
factor of 10000 greater than that for 6.7 GHz methanol masers associated with
Galactic high-mass star formation regions. The methanol emission is resolved on
scales smaller than 40 pc and it appears unlikely that it could be due to a
large concentration of Galactic-style star formation masers within a small
region. Comparison with observations of other methanol transitions suggests
that the 6.7 GHz methanol emission is due to a diffuse, low-gain maser,
amplifying the background continuum radiation from the nuclear region. The
methanol emission is blueshifted with respect to the the systemic velocity of
the galaxy by several hundred kilometers per second and lies outside the
velocity range associated with the dense gas and neutral hydrogen in the
central region of NGC4945. We speculate that it may be associated with gas
entrained in a superwind outflow from the nuclear region.
