Confirmation of the exclusive association between 6.7-GHz methanol
  masers and high-mass star formation regions
  Recently, a comparison between the locations of 6.7-GHz methanol masers and
dust continuum emission has renewed speculation that these masers can be
associated with evolved stars. The implication of such a scenario would be
profound, especially for the interpretation of large surveys for 6.7-GHz
masers, individual studies where high-mass star formation has been inferred
from the presence of 6.7-GHz methanol masers, and for the pumping mechanisms of
these masers. We have investigated the two instances where 6.7-GHz methanol
masers have been explicitly suggested to be associated with evolved stars, and
we find the first to be associated with a standard high-mass star formation
region, and the second to be a spurious detection. We also find no evidence to
suggest that the methanol maser action can be supported in the environments of
evolved stars. We thereby confirm their exclusive association with high-mass
star formation regions.
