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W. W. Chamberlain, J. S. Best (Astronomy and Physics Group, IES, Shepherd College)
We explore the use of fractal geometry in the examination of the connection between galaxy morphology and environment. A set referred to as fractal, following the point of view of K. Falconer, can be defined as a set with fine structure, some form of approximate or statistical self-similarity, and too irregular a structure to describe via traditional geometric language. As the distribution of galaxies has been shown to be similar on multiple scales, we find the use of fractal methodology appropriate for such studies.
We use an analytical tool known as the pointwise dimension (Holzfuss and Mayer-Kress 1986), which has its basis in fractal mathematics and has already been particularly illuminating for the study of correlations between galactic morphology and environment (e.g. Best 1999). We apply the pointwise dimension to the Southern Sky Redshift Survey, or SSRS2 (da Costa et al. 1998). The SSRS2 has 5369 galaxies with redshifts, magnitudes, and morphological classifications. As a preliminary result, we find that late-type galaxies have significantly different clustering environments than early-type galaxies, in some cases out to fitting ranges of 20 Mpc. This result holds not only if we compare specific morphologies to each other, but also if we consider all other galaxies (regardless of morphology) around a particular morphological type. This result bolsters the importance to a galaxy's evolution of its environment.
The author(s) of this abstract have provided an email address for comments about the abstract: jbest@shepherd.edu