Low-metallicity Young Clusters in the Outer Galaxy. III. Sh 2-127
  In deep near-infrared imaging of the low-metallicity (${\rm [O/H]}=-0.7$ dex)
H II region Sh 2-127 (S127) with Subaru/MOIRCS, we detected two young clusters
with 413 members (S127A) in a slightly extended H II region and another with
338 members (S127B) in a compact H II region. The limiting magnitude was
$K=21.3$ mag (10$\sigma$), corresponding to a mass detection limit of $\sim$0.2
$M_\odot$. These clusters are an order of magnitude larger than previously
studied young low-metallicity clusters and larger than the majority of solar
neighborhood young clusters. Fits to the K-band luminosity functions indicate
very young cluster ages of 0.5 Myr for S127A and 0.1-0.5 Myr for S127B,
consistent with the large extinction (up to $A_V\simeq20$ mag) from thick
molecular clouds and the presence of a compact H II region and class I source
candidates, and suggest that the initial mass function (IMF) of the
low-metallicity clusters is indistinguishable from typical solar neighborhood
IMFs. Disk fractions of $28\% \pm 3\%$ for S127A and $40\% \pm 4\%$ for S127B
are significantly lower than those of similarly aged solar neighborhood
clusters ($\sim$50$\%$-60$\%$). The disk fraction for S127B is higher than
those of previously studied low-metallicity clusters ($<$30 $\%$), probably due
to S127B's age. This suggests that a large fraction of very young stars in
low-metallicity environments have disks, but the disks are lost on a very short
timescale. These results are consistent with our previous studies of
low-metallicity star-forming regions, suggesting that a solar neighborhood IMF
and low disk fraction are typical characteristics for low-metallicity regions,
regardless of cluster scales.
