Aperture synthesis observations of shocked SO2 in the bipolar nebula OH 231.8+4.2

Observations of OH 2321.8+4.2, obtained with resolution 3 arcsec in the 104-GHz 3(1,3)-2(0,2) and 10(1,9)-10(0,10) lines of SO2 using the Hat Creek mm-wave interferometer from November 1987 to May 1988, are reported. The data are presented in extensive contour maps and graphs and characterized in detail. The distributions of both lines are found to be concentrated on the central star, and a blueshifted jet aligned with the bipolar lobes and H-alpha bubble is seen in the 3(1,3)-2(0,2) line. The shock interface between the outflowing gas and the local ISM is considered the most likely location for SO2 production. 17 references