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Session 25 - Galaxies, Clusters of Galaxies and their Evolution.
Oral session, Monday, June 08
Presidio,

[25.05] Neutral hydrogen in Hickson compact groups

B. A. Williams (U. Delaware)

VLA images of the neutral hydrogen (HI) in the direction of the Hickson compact groups (HCG) 2, 16, 23, 26, 33, 88, and 92 (Stephan's Quintet) are examined. In HCG 2 and 16, the HI gas is bound to the individual galaxies but shows definite signs of tidal interaction; in HCG 23, 26, 33, and 88 there are no obvious signs of tidal interactions in the HI distributions or velocity fields. In the more compact configuration, Stephan's Quintet, the HI gas is contained within a few prominent cloud features well displaced from the optical positions of any of the spiral members. In every case, the motions of the gas are consistent with the motions of the galaxies within these Hickson groups. A range of kinematical properties is observed for the HI gas, from the well-ordered rotational motions to small-scale systematic gradients within distinct cloud features.


The author(s) of this abstract have provided an email address for comments about the abstract: baw@udel.edu

Program listing for Monday