The Frequency of Warped HI Discs

  • A. Bosma
  • E. Athanassoula
Conference paper


We have recently made a small survey of ten edge-on galaxies, using the VLA in D-configuration (resolution 40″) in the 21-cm line. The purpose was to find non-warped galaxies extended in HI, suitable for a detailed study of the vertical equilibrium of their stellar and gas disks. Such a study might help to determine the shape of the dark halo component. As a byproduct, we have found several more examples of warped HI-discs. In Table 1 we collect the data on edge-on galaxies either observed by us, or already published elsewhere. For small warp amplitudes resolution effects become important: e.g. for NGC 100 our 40″ data does not indicate a warp, but recent mapping at 4″ resolution show a warp of small amplitude, as well as the expected flaring of the HI disc.




  1. Athanassoula, E., Bosma, A., Papaioannou, S.: 1987, Astr. Ap. 179. 23ADSGoogle Scholar
  2. Bottema, R., Shostak, G.S., Van der Kruit, P.C.: 1986, Astr. Ap. 167, 34ADSGoogle Scholar
  3. Bottema, R., Shostak, G.S., Van der Kruit, P.C.: 1987a, Nature 328, 401ADSCrossRefGoogle Scholar
  4. Bottema, R., Van der Kruit, P.C., Freeman, K.C.: 1987b, Astr. Ap. 178, 77ADSGoogle Scholar
  5. Gottesman, S.T., Hawarden,T.G.: 1986, M.N.R.A.S. 219, 759ADSGoogle Scholar
  6. Rupen, M.: 1989, Ph. D. thesis, Princeton UniversityGoogle Scholar
  7. Sancisi, R.: 1976, Astr. Ap. 53, 159ADSGoogle Scholar
  8. Sancisi, R., Allen, R.J.: 1979, Astr. Ap. 24, 73ADSGoogle Scholar
  9. Sparke, L.S., Casertano, S.: 1988, M.N.R.A.S. 234, 873ADSGoogle Scholar
  10. Van der Kruit, P.C., Searle, L.T.: 1982, Astr. Ap. 110, 79ADSGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • A. Bosma
    • 1
  • E. Athanassoula
    • 1
  1. 1.Observatoire de MarseilleMarseille Cedex 4France

Personalised recommendations