On the environments of type Ia supernovae within host galaxies
  We present constraints on supernovae type Ia (SNe~Ia) progenitors through an
analysis of the environments found at the explosion sites of 102 events within
star-forming host galaxies. H-alpha and GALEX near-UV images are used to trace
on-going and recent star formation (SF), while broad band B, R, J, K imaging is
also analysed. Using pixel statistics we find that SNe~Ia show the lowest
degree of association with H-alpha emission of all supernova types. It is also
found that they do not trace near-UV emission. As the latter traces SF on
timescales less than 100 Myr, this rules out any extreme 'prompt' delay-times
as the dominant progenitor channel of SNe~Ia. SNe~Ia best trace the B-band
light distribution of their host galaxies. This implies that the population
within star-forming galaxies is dominated by relatively young progenitors.
Splitting SNe by their (B-V) colours at maximum light, 'redder' events show a
higher degree of association to HII regions and are found more centrally within
hosts. We discuss possible explanations of this result in terms of line of
sight extinction and progenitor effects. No evidence for correlations between
SN stretch and environment properties is observed.
