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Session 6 - Evolution, Survey and Clusters of Galaxies.
Display session, Monday, June 10
Aperture synthesis observations in the 21cm line of HI are presented for the galaxy pair II Zw 70/71. II Zw 71 is one of the closest candidate polar-ring galaxies (cz = 1250 km s^-1), in which a ring of gas, dust and stars appear to orbit nearly over the pole of a central disk galaxy. The companion galaxy, II Zw 70, has a very bright blue central disk and irregular jets or plumes in stellar light. Most of the HI appears to belong to one or other of the galaxies, but a contiguous bridge of gas between them contains a significant fraction of the neutral gas. Our HI distribution and velocity field provides a unique opportunity to study what may be a polar ring in the process of formation. The [OI]1302Å\ line has been detected but not resolved in II Zw 70, in observations with the Goddard High-Resolution Spectrograph on the HST; we will use our measured HI velocity dispersion to estimate the width of the 1302Å\ line, and hence derive heavy-element abundances in the neutral medium.
Program listing for Monday