A study of spiral galaxies. Using HI synthesis observations and photographic surface photometry

An interesting and important problem in extragalactic research is the origin and evolution of spiral galaxies. Spiral galaxies exist in a variety of morphological shapes and it is now evident that differences in the morphologies among spiral galaxies relate to continuous variations in a number of basic physical parameters. Until the definition and beginning of the survey project as described in this thesis, the available information is contained in a number of different studies which mosly deal with integral properties of spiral galaxies. To investigate the problem furtherit became clear that one needs the detailed radial distributions of both the gaseous and the stellar components for a well-defined sample of spiral galaxies. Specific questions that are investigated are: 1) what is radial dependence of star formation and how is it related tot morphology? 2) what determines the star formation within and between galaxies? 3) are the dynamical state and the light distribution connected? 4) are abundance gradients related to other parameters? 5) is there dark matter and if so, what fraction of the total mass does it contribute? ... Introduction and summary