The spindle: an irradiated disk and bent protostellar jet in Orion.
BALLY J., YOUNGBLOOD A. and GINSBURG A.
Abstract (from CDS):
We present Hubble Space Telescope observations of a bent, pulsed Herbig-Haro jet, HH 1064, emerging from the young star Parenago 2042 embedded in the H II region NGC 1977 located about 30' north of the Orion Nebula. This outflow contains eight bow shocks in the redshifted western lobe and five bow shocks in the blueshifted eastern lobe. Shocks within a few thousand AU of the source star exhibit proper motions of ∼160 km/s but motions decrease with increasing distance. Parenago 2042 is embedded in a proplyd–a photoevaporating protoplanetary disk. A remarkable set of Hα arcs resembling a spindle surround the redshifted (western) jet. The largest arc with a radius of 500 AU may trace the ionized edge of a circumstellar disk inclined by ∼30°. The spindle may be the photoionized edge of either a ∼3 km/s FUV-driven wind from the outer disk or a faster MHD-powered flow from an inner disk. The HH 1064 jet appears to be deflected north by photoablation of the south-facing side of a mostly neutral jet beam. V2412 Ori, located 1' west of Parenago 2042 drives a second bent flow, HH 1065. Both HH 1064 and 1065 are surrounded by LL Ori-type bows marking the boundary between the outflow cavity and the surrounding nebula.