Kinematics and chemistry of the hot core in G20.08-0.14N
  We present Submillimeter Array observations of the massive star-forming
region G20.08-0.14N at 335 and 345 GHz. With the SMA data, 41 molecular
transitions were detected related to 11 molecular species and their
isotopologues, including SO2, SO, C34S, NS, C17O, SiO, CH3OH, HC3N, H13CO+,
HCOOCH3 and NH2CHO. In G20.08-0.14N, 10 transition lines of the detected 41
transition lines belong to SO2, which dominates the appearance of the
submillimeter-wave spectrum. To obtain the spatial kinematic distribution of
molecules in G20.08-0.14N, we chose the strongest and unblended lines for the
channel maps. The channel maps of C34S an SiO, together with their
position-velocity diagrams, present that there are two accretion flows in
G20.08-0.14N. Additionally, SiO emission shows a collimated outflow at the
NE-SW direction. The direction of the outflow is for the first time revealed.
The rotational temperature and the column density of CH3OH are 105 K and
3.1*10^{17} cm^{-2}, respectively. Our results confirm that a hot core is
associated with G20.08-0.14N. The hot core is heated by a protostar radiation
at it center, not by the external excitation from shocks. The images of the
spatial distribution of different species have shown that the different
molecules are located at the different positions of the hot core. Through
comparing the spatial distributions and abundances of the molecules, we discuss
possible chemical processes for producing the complex sulfur-bearing,
nitrogen-bearing and oxygen-bearing molecules in G20.08-0.14N.
