Nobeyama 45-m Mapping Observations toward Orion A.I. Molecular Outflows
  We conducted an exploration of 12CO molecular outflows in the Orion A giant
molecular cloud to investigate outflow feedback using 12CO (J = 1-0) and 13CO
(J = 1-0) data obtained by the Nobeyama 45-m telescope. In the region excluding
the center of OMC 1, we identified 44 12CO (including 17 newly detected)
outflows based on the unbiased and systematic procedure of automatically
determining the velocity range of the outflows and separating the cloud and
outflow components. The optical depth of the 12CO emission in the detected
outflows is estimated to be approximately 5. The total momentum and energy of
the outflows, corrected for optical depth, are estimated to be 1.6 x 10 2 M km
s-1 and 1.5 x 10 46 erg, respectively. The momentum and energy ejection rate of
the outflows are estimated to be 36% and 235% of the momentum and energy
dissipation rates of the cloud turbulence, respectively. Furthermore, the
ejection rates of the outflows are comparable to those of the expanding
molecular shells estimated by Feddersen et al. (2018, ApJ, 862, 121). Cloud
turbulence cannot be sustained by the outflows and shells unless the energy
conversion efficiency is as high as 20%.
