Interferometric observations of the (C-18)O and (C-12)O J = 1-0 transitions, and the NH3 (1, 1) and (2, 2) transitions toward the young far-IR source IRAS 16293-2422 are presented. The data reveal elongated gas structures which are aligned perpendicular to the axis of a bipolar outflow and to the local magnetic field direction. By combining the interferometric data with single-dish spectra of the (C-18)O and (C-17)O lines, a comprehensive model for the IRAS 16293-2422 region is developed. In this model, the compact (C-18)O line and 40 K dust emission arise from rotating material within which the central heat source is embedded. The NH3 emission is distributed in a ring with radius 3000 to 4000 AU surrounding the central disk. The dearth of ammonia emission from the (C-18)O emission region is attributed to an actual decrease in NH3 abundance.
The Astrophysical Journal
Mundy, Lee; Wootten, H.; and Wilking, Bruce, "The Circumstellar Structure of IRAS 16293-2422: C18O, NH3 , and CO Observations" (1990). Physics Faculty Works. 52.
Available at: https://irl.umsl.edu/physics-faculty/52