Multiple Jets in the Bursting Protostar HOPS 373SW

Abstract

We present the outflows detected in HOPS 373SW, a protostar undergoing a modest 30% brightness increase at 850 μ m. Atacama Large Millimeter/submillimeter Array observations of shock tracers, including SiO 8–7, CH _3 OH 7 _k –6 _k , and ^12 CO 3–2 emission, reveal several outflow features around HOPS 373SW. The knots in the extremely high-velocity SiO emission reveal the wiggle of the jet, for which a simple model derives a 37° inclination angle of the jet to the plane of the sky, a jet velocity of 90 km s ^−1 , and a period of 50 yr. The slow SiO and CH _3 OH emission traces U-shaped bow shocks surrounding the two CO outflows. One outflow is associated with the high-velocity jets, while the other is observed to be close to the plane of the sky. The misaligned outflows imply that previous episodic accretion events have either reoriented HOPS 373SW or that it is an unresolved protostellar binary system with misaligned outflows.

Keywords

• Protostars
• Jets
• Shocks