Over the last few years, we have been attempting to refine the measurement of secondary distances to field spirals using the Tully-Fisher relation. Our main objectives in designing and undertaking such a survey are:

  • The main idea was to conduct an all-sky survey of a large number (2000) of spiral galaxies in order to apply the Tully-Fisher relation to determine peculiar motions in the local universe.

  • The ScI survey combines photometric I-band CCD imaging with high sensitivity 21 cm HI line observations. We have gone to great lengths to insure uniformity of the data taking, data processing and analysis.

  • The careful sample definition, large sample size and uniform coverage both on the sky and in depth allows analysis of Malmquist and selection bias, completeness, and statistical uncertainties for comparison with models and reconstruction of the density field.

  • In the early stages of the project, we attempted to coordinate our project with the southern hemisphere observations of Mathewson, Ford and Buckhorn (1992, Ap.J.Suppl. 81, 413). At the invitation of Don Mathewson, Riccardo and Martha spent 6 weeks at the ANU in 1990, participated in observations at Parkes and Siding Springs, and helped developed the pipeline for data reduction. It was winter in Ithaca and summertime in Australia, so they really didn't mind. Luiz kindly provided many of the southern redshifts in advance of publication.

  • We restricted our sample to galaxies of morphological type Sbc-Sc only in order to minimize possible type-dependent variations in fundamental parameters such as the mass-to-light ratio.

  • We also conducted a close examination of the intrinsic properties of the Sbc-Sc galaxy class using the survey data to examine effects on observed properties of viewing aspect, internal extinction, environment.

  • Related Publications

        The SFI survey team:

    Pierre Chamaraux (Meudon)
    Luiz N. da Costa (ESO/Obs. Nac. Brasil)
    Wolfram Freudling (ESO)
    Riccardo Giovanelli (Cornell/NAIC)
    Martha Haynes (Cornell/NAIC)
    John Salzer (Wesleyan)
    Gary Wegner (Dartmouth)