Core-collapse supernova progenitor constraints using the spatial
  distributions of massive stars in local galaxies
  We study the spatial correlations between the H$\alpha$ emission and
different types of massive stars in two local galaxies, the Large Magellanic
Cloud (LMC) and Messier 33. We compare these to correlations derived for
core-collapse supernovae (CCSNe) in the literature to connect CCSNe of
different types with the initial masses of their progenitors and to test the
validity of progenitor mass estimates which use the pixel statistics method. We
obtain samples of evolved massive stars in both galaxies from catalogues with
good spatial coverage and/or completeness, and combine them with coordinates of
main-sequence stars in the LMC from the SIMBAD database. We calculate the
spatial correlation of stars of different classes and spectral types with
H$\alpha$ emission. We also investigate the effects of distance, noise and
positional errors on the pixel statistics method. A higher correlation with
H$\alpha$ emission is found to correspond to a shorter stellar lifespan, and we
conclude that the method can be used as an indicator of the ages, and therefore
initial masses, of SN progenitors. We find that the spatial distributions of
type II-P SNe and red supergiants of appropriate initial mass ($\gtrsim$9
$M_{\odot}$) are consistent with each other. We also find the distributions of
type Ic SNe and WN stars with initial masses $\gtrsim$20 $M_{\odot}$
consistent, while supergiants with initial masses around 15 $M_{\odot}$ are a
better match for type IIb and II-L SNe. The type Ib distribution corresponds to
the same stellar types as type II-P, which suggests an origin in interacting
binaries. On the other hand, we find that luminous blue variable stars show a
much stronger correlation with H$\alpha$ emission than do type IIn SNe.
