The 2dF Galaxy Redshift Survey: Hierarchical galaxy clustering

Jan, 2004
5 pages
Published in:
  • Mon.Not.Roy.Astron.Soc. 351 (2004) L44
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Abstract: (arXiv)
We use the two-degree field Galaxy Redshift Survey (2dFGRS) to test the hierarchical scaling hypothesis: namely, that the pp-point galaxy correlation functions can be written in terms of the two point correlation function or variance. This scaling is expected if an initially Gaussian distribution of density fluctuations evolves under the action of gravitational instability. We measure the volume averaged pp-point correlation functions using a counts in cells technique applied to a volume limited sample of 44,931 LL_* galaxies. We demonstrate that LL_{*} galaxies display hierarchical clustering up to order p=6p=6 in redshift space. The variance measured for LL_{*} galaxies is in excellent agreement with the predictions from a Λ\Lambda-cold dark matter N-body simulation. This applies to all cell radii considered, 0.3<(R/h1Mpc)<300.3<(R/h^{-1}{\rm Mpc})<30. However, the higher order correlation functions of LL_* galaxies have a significantly smaller amplitude than is predicted for the dark matter for R<10h1R<10h^{-1}Mpc. This disagreement implies that a non-linear bias exists between the dark matter and LL_* galaxies on these scales. We also show that the presence of two rare, massive superclusters in the 2dFGRS has an impact on the higher-order clustering moments measured on large scales.
Note:
  • 5 pages, 4 figures. Slight revisions to match version published in MNRAS Journal-ref: 2004, MNRAS, 351, L44-L48