Statistical studies of supernova environments
  Investigations of the environments of SNe allow statistical constraints to be
made on progenitor properties. We review progress that has been made in this
field. Pixel statistics using tracers of e.g. star formation within galaxies
show differences in the explosion sites of, in particular SNe types II and Ibc
(SNe II and SNe Ibc), suggesting differences in population ages. Of particular
interest is that SNe Ic are significantly more associated with H-alpha emission
than SNe Ib, implying shorter lifetimes for the former. In addition, such
studies have shown that the interacting SNe IIn do not explode in regions
containing the most massive stars, which suggests that at least a significant
fraction of their progenitors arise from the lower end of the core-collapse SN
mass range. Host HII region spectroscopy has been obtained for a significant
number of core-collapse events, however definitive conclusions have to-date
been elusive. Single stellar evolution models predict that the fraction of SNe
Ibc to SNe II should increase with increasing metallicity, due to the
dependence of mass-loss rates on progenitor metallicity. We present a
meta-analysis of host HII region oxygen abundances for CC SNe. It is concluded
that the SN II to SN Ibc ratio shows little variation with oxygen abundance,
with only a suggestion that the ratio increases in the lowest bin. Radial
distributions of different SNe are discussed, where a central excess of SNe Ibc
has been observed within disturbed galaxy systems, which is difficult to
ascribe to metallicity or selection effects. Environment studies are evolving
to enable studies at higher spatial resolutions than previously possible, while
in addition the advent of wide-field integral field unit instruments allows
galaxy-wide spectral analyses which will provide fruitful results to this
field. Some example contemporary results are shown in that direction.
