SMA CO (2–1) Observations of CG30: a Protostellar Binary System with a High-Velocity Quadrupolar Molecular Outflow

We present interferometric observations in the CO(2–1) line and at 1.3mm dust continuum of the low-mass protostellar binary system in the cometary globule CG30, using the Submillimeter Array. The dust continuum images resolve two compact sources (CG30N and CG30S), with a linear separation of∼ 8700AU and total gas masses of∼ 1.4 and∼ 0.6M⊙, respectively. With the CO images, we discover two high-velocity bipolar molecular outflows, driven by the two sources. The two outflows are nearly perpendicular to each other, showing a quadrupolar morphology. The northern bipolar outflow extends along the southeast (redshifted, with a velocity up to ∼ 23 km s) and northwest (blueshifted, velocity up to ∼ 30 km s) directions, while the southern pair has an orientation from southwest (blueshifted, velocity up to ∼ 13 km s) to northeast (redshifted, velocity up to ∼ 41 km s). The outflow mass of the northern pair, driven by the higher mass source CG30N, is ∼ 9 times larger than that of the southern pair. The discovery of the quadrupolar molecular outflow in the CG30 protobinary system, as well as the presence of other quadrupolar outflows associated with binary systems, demonstrate that the disks in (wide) binary systems are not necessarily co-aligned after fragmentation. Subject headings: binaries: general — ISM: jets and outflows — ISM: individual (CG30, BHR12) — stars: formation