Kk. Dyer et al., Australia Telescope Compact Array observations of the OH star Roberts 22: Resolved images of hydroxyl emission, ASTRONOM J, 121(5), 2001, pp. 2743-2751
We have imaged the unusual OH/IR object G284-0.8 (Roberts 22) in the OH tra
nsitions at 1612, 1665, and 1667 MHz using the Australia Telescope Compact
Array in Narrabri, NSW, Australia. The angular resolution of the OH images
we present here is 6 " (12,000 AU at a distance of 2 kpc). We find OH emiss
ion of extent 1."5 (2800 AU) located inside the optical bipolar flow region
(size 8 ") discovered in the early eighties by Allen et al. and imaged rec
ently by Sahai et al. with the Hubble Space Telescope. We present astrometr
y of Roberts 22, providing registration of the OH and Hubble Space Telescop
e images to within similar to0." 35. We describe the OH velocity field in R
oberts 22 and discuss the kinematic properties of the source and its evolut
ionary status.