Environments of interacting transients: Impostors and type IIn
  supernovae
  This paper presents one of the first environmental analyses of the locations
of the class of `interacting transients', namely type IIn supernovae and
supernova Impostors. We discuss the association of these transients with star
formation, host galaxy type, metallicity, and the locations of each event
within the respective host. Given the frequent assumption of very high mass
progenitors for these explosions from various studies, most notably a direct
progenitor detection, it is interesting to note the weak association of these
subtypes with star formation as traced by H{\alpha} emission, particularly in
comparison with type Ic supernovae, which trace the H{\alpha} emission and are
thought to arise from high mass progenitors. The radial distributions of these
transients compared to type Ic supernovae are also very different. This
provides evidence for the growing hypothesis that these `interacting
transients' are in fact comprised of a variety of progenitor systems. The
events contained within this sample are discussed in detail, where information
in the literature exists, and compared to the environmental data provided.
Impostors are found to split into two main classes, in terms of environment:
SN2008S-like Impostors fall on regions of zero H{\alpha} emission, whereas
{\eta}-Carina-like Impostors all fall on regions with positive H{\alpha}
emission. We also find indications that the Impostor class originate from lower
metallicity environments than type IIn, Ic and IIP SNe.
