Metallicity Estimation of Core-Collapse Supernova HII Regions in
  Galaxies within 30 Mpc
  This work presents measurements of the local HII environment metallicities of
core-collapse supernovae (SNe) within a luminosity distance of 30 Mpc. 76
targets were observed at the Isaac Newton Telescope and environment
metallicities could be measured for 65 targets using the N2 and O3N2 strong
emission line method. The cumulative distribution functions (CDFs) of the
environment metallicities of Type Ib and Ic SNe tend to higher metallicity than
Type IIP, however Type Ic are also present at lower metallicities whereas Type
Ib are not. The Type Ib frequency distribution is narrower (standard deviation
$\sim$0.06 dex) than the Ic and IIP distributions ($\sim$0.15 dex) giving some
evidence for a significant fraction of single massive progenitor stars; the low
metallicity of Type Ic suggests a significant fraction of compact binary
progenitors. However, both the Kolmogorov-Smirnov test and the Anderson-Darling
test indicate no statistical significance for a difference in the local
metallicities of the three SN types. Monte-Carlo simulations reveal a strong
sensitivity of these tests to the uncertainties of the derived metallicities.
Given the uncertainties of the strong emission methods, the applicability of
the tests seems limited. We extended our analysis with the data of the Type
Ib/Ic/IIP SN sample from Galbany et al. (2018). The CDFs created with their
sample confirm our CDFs very well. The statistical tests, combining our sample
and the Galbany et al. (2018) sample, indicate a significant difference between
Type Ib and Type IIP with <5% probability that they are drawn from the same
parent population.
