Discovery of seven bipolar outflows by an unbiased survey

Abstract

The discovery of seven CO outflows in an unbiased CO survey with the Nagoya 4 m millimeter telescope of the Orion southern giant molecular cloud and a few other dark clouds is reported. In the Orion southern cloud four regions of outflows have been found in addition to three regions previously detected, suggesting that the number of outflow sources may be increased by 50-90 percent through unbiased surveys. The total mechanical luminosity of the outflows in this cloud is about 2 solar luminosities. This luminosity can provide the kinetic energy of the cloud in about 5 Myr, a time scale which is nearly equal to that of turbulence dissipation, about 7 Myr, but is longer than the free-fall time of 1 Myr. Therefore, outflows can support the giant molecular cloud if turbulence dissipates in a time scale an order of magnitude longer than the free-fall time.