Multiple monopolar outflows driven by massive protostars in IRAS
  18162-2048
  In this paper we present Combined Array for Research in Millimeter-wave
Astronomy (CARMA) 3.5 mm observations and SubMillimeter Array (SMA) 870 microns
observations toward the high-mass star-forming region IRAS 1816-2048, the core
of the HH 80/81/80N system. Molecular emission from HCN, HCO+ and SiO is
tracing two molecular outflows (the so-called Northeast and Northwest
outflows). These outflows have their origin in a region close to the position
of MM2, a millimeter source known to harbor a couple protostars. We estimate
for the first time the physical characteristics of these molecular outflows,
which are similar to those of 1000-5000 Lo protostars, suggesting that MM2
harbors high-mass protostars. High-angular resolution CO observations show an
additional outflow due southeast. We identify for the first time its driving
source, MM2(E), and see evidence of precession. All three outflows have a
monopolar appearance, but we link the NW and SE lobes, explaining their
asymmetric shape as a consequence of possible deflection.
