H{\alpha} to FUV ratios in resolved star forming region populations of
  nearby spiral galaxies
  We present a new study of H{\alpha}/FUV flux ratios of star forming regions
within a sample of nearby spiral galaxies. We search for evidence of the
existence of a cluster mass dependent truncation in the underlying stellar
initial mass function (IMF). We use an automated approach to identification of
extended objects based on the SExtractor algorithm to catalogue resolved Hii
regions within a set of nearby spiral galaxies. Corrections due to dust
attenuation effects are applied to avoid artificially boosted H{\alpha}/FUV
values. We use the BPASS stellar population synthesis code of Eldridge &
Stanway (2009) to create a benchmark population of star forming regions to act
as a reference for our observations. Based on those models, we identify a zone
of parameter space populated by regions that cannot be obtained with a cluster
mass dependent truncation in the stellar IMF imposed. We find that the
investigated galaxies display small subpopulations of star forming regions
falling within our zone of interest, which appears to be inconsistent with
imposing an IMF truncation at maximum stellar mass dependent on the total
cluster mass. The presence of those regions is expected in models using both
stochastic and sorted sampling of the full extent of the stellar IMF. This
result persists after taking dust attenuation effects into account. We
highlight the significance of stochastic effects in environments with low star
formation activity and in studies describing systems associated with small
physical scales.
