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arXiv · 0903.1803

Comparing Correlation Lengths of Red and Blue Galaxies: A New Standard Length for Testing Cosmic Isotropy

Michael J. Longo
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Abstract

I introduce a simple empirical measure of average galaxy cluster sizes based on a comparison of the correlation lengths of red galaxies with blue that can provide a more accurate and bias-free measure of the average size and number density of galaxy clusters. Using 269,000 galaxies from the SDSS DR6 survey, I show that this 3D correlation length, averaged over many clusters, remains very nearly constant at L0= 4.797 +/- 0.024 Mpc/h from small redshifts out to redshifts of 0.5. This serves as a new measure of cosmic length scales and provides a means of testing the standard cosmological model that is almost free of selection biases. The unprecedented accuracy of the technique allows the possibility of sensitive searches for large-scale inhomogeneities. Applying the same technique to the Millennium Simulation galaxies I find very good agreement between it and the SDSS galaxies.

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Michael J. Longo. 2009-03-10. Comparing Correlation Lengths of Red and Blue Galaxies: A New Standard Length for Testing Cosmic Isotropy. https://arxiv.org/abs/0903.1803

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