The redshift selected sample of long gamma-ray burst host galaxies: the
  overall metallicity distribution at $z < 0.4$
  We discuss the host galaxy metallicity distribution of all long gamma-ray
bursts (GRBs) whose redshifts are known to be $< 0.4$, including newly obtained
spectroscopic datasets of the host galaxies of GRB 060614, 090417B, and
130427A. We compare the metallicity distribution of the low-redshift sample to
the model predictions, and constrain the relation between metallicity and GRB
occurrence. We take account of spatial variation of metallicities among star
forming regions within a galaxy. We found that the models, in which only
low-metallicity stars produce GRBs with a sharp cutoff of GRB production
efficiency around 12+log(O/H) $\sim$ 8.3, can well reproduce the observed
distribution, while the models with no metallicity dependence are not
consistent with the observations. We also discuss possible sampling biases we
may suffer by collecting long GRBs whose redshifts are known, presenting the
photometric observations of the host galaxy of GRB 111225A at $z = 0.297$ whose
redshift has been undetermined until $\sim$ 2.3 years after the burst.
