NGC 2655 and NGC 3718: Galaxies with Warped Polar Disks

Type Conference Paper
Names Linda S. Sparke, G. van Moorsel, U. Schwarz, P. Erwin, E. M. H. Wehner, M. Vogelaar
Proceedings Title Bulletin of the American Astronomical Society
Conference Name American Astronomical Society, AAS Meeting #211, #13.11
Volume 39
Pages 756
Date December 1, 2007
Short Title NGC 2655 and NGC 3718
Library Catalog NASA ADS
Abstract NGC 2655 and NGC 3718 are nearby bright S0/Sa galaxies with strongly asymmetric central dust lanes and an extended disk of neutral hydrogen gas. Deep optical images show tidal arms and regions of diffuse starlight well beyond the main galaxy, suggestive of a recent merger. Our VLA 21cm maps made show a layer of neutral hydrogen extending to at least 40kpc from the center. In both systems the pattern of gas velocities is generally bisymmetric, but the HI layer is strongly warped; it does not share the kinematics of the stellar disk. The gas orbits twist by at least 90ο as the HI layer appears to warp through edge-on. In NGC 3718, we combine a tilted-ring fit to the HI data cube with dynamical modeling to put constraints on the flattening of the galaxy's dark halo. We thank the NSF, NSERC Canada, and the German DFG for grant support.
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