Identifying the outflow driving sources in Orion-KL

The enigmatic outflows of the Orion-KL region have raised discussions about their potential driving sources for several decades. Here, we present (CO)-O-18(2-1) observations combined from the Submillimeter Array and the IRAM 30 m telescope. The molecular gas is associated on large scales with the famous northwest-southeast high-velocity outflow, whereas the high-velocity gas on small spatial scales traces back to the recently identified submm source SMA1. Therefore, we infer that SMA1 may host the driving source of this outflow. Based on the previously published thermal and maser SiO data, source I is the prime candidate to drive the northeast-southwest low-velocity outflow. The source SMA1 is peculiar because it is detected only in several submm wavelength bands but neither in the infrared nor cm regime. We discuss that it may be a very young intermediate- to high-mass protostar. The estimated outflow masses are high, whereas the dynamical timescale of the outflow is short, of the order 10(3) yr.