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E. A. Praton, J. Bilikova (Franklin & Marshall Coll.), A. L. Melott, B. C. Thomas (UKansas)
We present the results of an investigation into the method proposed by Melott et al. (1998) for quantifying the bull's-eye effect in maps of large scale structure. The bull's-eye effect is a distortion in redshift-space produced by peculiar velocities. Structures lying across the line of sight are enhanced, but structures lying along the line of sight are not, producing an impression of walls ringing the observer (Praton, Melott, & McKee 1997), much like those seen in recent large scale surveys. Simulations show that the strength of the pattern varies with initial cosmological conditions; thus, our interest in developing a reliable way to quantify the effect, as a possible way to independently determine parameters such as \Omega.
Thomas et al. (2004) showed that the proposed method can successfully distinguish between high and low \Omega simulations, independent of bias, for thin slices in the cartesian limit. We carry that investigation further, looking at thick slices in the cartesian limit. Since the bull's-eye pattern grows stronger as slice thickness increases (Praton, Melott, & Peterson 1997), we expect the method to become more reliable. Instead, we find the opposite. We discuss the reasons, as well as results from one or two possible alternatives.
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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.