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Wentao Wu (Louisiana State University), Renato A. Dupke (University of Michigan)
Statistical samples of local field galaxies (z \lesssim 0.03) of various morphological types are derived from the Third Reference Catalogue of Bright Galaxies (RC3). >From the samples, the B-band luminosity functions are evaluated with \langle V/V\mbox{max} \rangle methods (including certain modifications) for various morphological types: E/S0, S0a/Sa/Sab, Sb/Sbc, Sc/Scd, Sd/Sdm, and Sm/Im/I0. Possible members of galaxy clusters have been systematically removed so that the results represent well those of field galaxies. Therefore, the results of this work are useful to provide local templates in calculating the population evolution of field galaxies, which accounts for the vast majority of the galaxies in the universe, and to compare to galaxy luminosity functions in clusters, which provides clues to the impact of environment on the galaxy evolution. Overall, the luminosity function of the E/S0 galaxies can be well explained by the ``merger hypothesis,'' i.e., most local E/S0 galaxies are remnants of galaxy merging. The luminosity function of Sm/Im/I0 galaxies has steep (Schecter) slope: \alpha \approx -2.0, which is consistent with other recent surveys of the nearby universe. The steep slope supports the mild evolution of irregular galaxies in explaining the rapid increase of their number counts from HST deep sky surveys. It also indicates the presence of large amounts of baryonic matter in dwarf irregular galaxies traditionally unaccounted for. The parameterizations of the luminosity functions are also discussed.