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We have carried out a spatial-kinematical study of three proto-planetarynebulae, IRAS 16594-4656, Hen 3-401, and Rob 22. High-resolution H2 images wereobtained with NICMOS on the HST and high-resolution spectra were obtained withthe Phoenix spectrograph on Gemini-South. IRAS 16594-4656 shows a"peanut-shaped" bipolar structure with H2 emission from the walls and from twopairs of more distant, point-symmetric faint blobs. The velocity structureshows the polar axis to be in the plane of the sky, contrary to the impressiongiven by the more complex visual image and the visibility of the central star,with an ellipsoidal velocity structure. Hen 3-401 shows the H2 emission comingfrom the walls of the very elongated, open-ended lobes seen in visible light,along with a possible small disk around the star. The bipolar lobes appear tobe tilted 10-15 deg with respect to the plane of the sky and their kinematicsdisplay a Hubble-like flow. In Rob 22, the H2 appears in the form of an "S"shape, approximately tracing out the similar pattern seen in the visible. H2 isespecially seen at the ends of the lobes and at two opposite regions close tothe unseen central star. The axis of the lobes is nearly in the plane of thesky. Expansion ages of the lobes are calculated to be approximately 1600 yr(IRAS 16594-4656), 1100 yr (Hen 3-401), and 640 yr (Rob 22), based uponapproximate distances.

A Study of H2 Emission in Three Bipolar Proto-Planetary Nebulae: IRAS 16594-4656, Hen 3-401, and Rob 22