Both high- and low-velocity outflows are occasionally observed around a protostar by molecular line emission. The high-velocity component with a velocity of ≳ 50 − 100 km/s is called "Extremely High-Velocity (EHV) flow," while the component with a velocity of ~ 10 km/s is simply referred to as "(molecular) outflow." Since these flows are observed only in an early phase of star formation, they are considered to be a pivotal target to clarify the star formation process. This study reports a newly

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... found EHV flow and outflow around MMS 5 in the Orion Molecular Cloud 3 observed with ALMA. The EHV flow is detected with CO J =2–1 and SiO J =5–4 line emissions. CO J =2–1 emission traces both the EHV flow and outflow. In addition, SiO J=5–4 emission, which only traces the EHV flow, and has a considerably collimated structure which includes several knots. The high-velocity collimated component (EHV flow) is located at the root of the V- shaped low-velocity outflow. Dynamical timescale of the EHV flow is smaller than that of the outflow by a factor of ~3. Moreover, the axis between the outflow and the EHV flow is different. The flow driving mechanism is discussed in terms of the dynamical timescale and different P.A. between the EHV flow and outflow and the periodicity of the knots. In addition, the directions of the EHV flow and the outflow are roughly perpendicular to the major axis of the rotating disk-like structure which is observed in the 1.3 mm continuum and C18O J=2–1 line emission. We suggest these evidences possibly support the MHD wind model.