Clustering Analysis as a Method of Auto-Classification and Its Application to the Search for Galaxy Chains in Two Dimensions
Filaments and lines of galaxies on the sky have been discussed in recent years. The present paper outlines a method for quantitatively testing the connected nature of these features. Comparison with Monte Carlo simulations give probability values that the features are real.
Two large scale alignments of galaxies in the sky are tested. In the region 7h < R.A. < 11h, 30° < Dec. < 65° filaments of galaxies of 3500 < cz0 < 5500 kms-1 and 4200 < cz0 < 5200 kms-1 are shown to be significant. The second field at 12h30m < R.A. < 15h30m, 35° < Dec. < 70° shows a string like structure recognized here for the first time for galaxies with redshifts 2300 < cz0 < 2800 kms-1.
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- Focardi, P., Marano, B., and Vettolani, G., ESQ preprint No. 420.Google Scholar