Chemical composition in the IRAS 16562--3959 high-mass star-forming
  region
  We have analyzed the Atacama Large Millimeter/submillimeter Array (ALMA)
cycle 2 data of band 6 toward the G345.4938+01.4677 massive young protostellar
object (G345.5+1.47 MYSO) in the IRAS 16562--3959 high-mass star-forming region
with an angular resolution of $\sim 0.3"$, corresponding to $\sim 760$ au. We
spatially resolve the central region which consists of three prominent
molecular emission cores. A hypercompact (HC) H$_{\rm {II}}$ region (Core A)
and two molecule-rich cores (Core B and Core C) are identified using the moment
zero images of the H30$\alpha$ line and a CH$_{3}$OH line, respectively.
Various oxygen-bearing complex organic molecules (COMs), such as
(CH$_{3}$)$_{2}$CO and CH$_{3}$OCHO, have been detected toward the positions of
Core B and Core C, while nitrogen-bearing species, CH$_{3}$CN, HC$_{3}$N and
its $^{13}$C isotopologues, have been detected toward all of the cores. We
discuss the formation mechanisms of H$_{2}$CO by comparing the spatial
distribution of C$^{18}$O with that of H$_{2}$CO. The $^{33}$SO emission, on
the other hand, shows a ring-like structure surrounding Core A, and it peaks on
the outer edge of the H30$\alpha$ emission region. These results imply that SO
is enhanced in a shock produced by the expanding motion of the ionized region.
