2000ApJ...535..833S

We present images of the molecular gas in the IRAS 20126+4104 massive outflow and examine the interaction between the energetic outflowing material and the surrounding molecular cloud. Mosaic interferometric images in CO(1-0), ¹³CO(1-0), C¹⁸O(1-0), C¹⁷O(1-0), and millimeter continuum emission are compared with mid-infrared images at 12.5 and 17.9 µm, near-infrared images in the K_s band (2.17 µm) and H₂ line emission, and optical Hα and [S II] images. We show that the molecular outflow is approximately 6x10⁴ yr old with a mass of about 50-60 M_☉ and mass outflow rate M{dot}_f∼8x10^–4 M_☉.yr^–1. The driving source is located near the center of the ≳300 M_☉ molecular cloud, and the mass of the disk plus circumstellar envelope traced by millimeter continuum emission is ∼50 M_☉. The outflow appears to be bounded on most sides by higher density gas traced by C¹⁸O emission. Shocks identified by H₂ and [S II] emission knots follow a NW-SE jet close to the young stellar object and then rotate more north-south along the edges of the CO flow. The most likely interpretation appears to be that the knots trace the working surfaces of a collimated jet that precesses through an angle of ∼45°. Possible mechanisms that could produce the jet precession include tidal interactions between the disk and a companion star in a noncoplanar orbit or an anisotropic accretion event that dramatically altered the angular momentum vector of the disk.