Vol 9, No 9 (2009) / Ma

Clustering of K-band selected local galaxies

Bin Ma, Ke-Lai Meng, Jun Pan, Jia-Sheng Huang, Long-Long Feng

Abstract

We present a detailed clustering analysis of a large K-band selected local galaxy sample, which is constructed from the 2MASS and the SDSS and consists of 82 486 galaxies with 10 < K < 13.5 and 0.01 < z < 0.1. The two-point correlation function of the magnitude-limited sample in real space at small scales is well described by the power law ξ(r) = (r/6.44 ± 0.23)1.81±0.02. The pairwise velocity dispersion is derived from the anisotropic two-point correlation function and we find the dispersion σ12 = 685 ± 17 kms-1 if scale invariance is assumed, which is larger than values measured in the optical bands of the selected galaxy samples. We further investigate the dependence of the two-point correlation function and the σ12 on the gr color and theKband luminosity, and obtain similar results to previous works in optical bands. Comparing a mock galaxy sample with our real data indicates that the semi-analytical model cannot mimic the σ12 in observation, although it can approximate the two-point correlation function within measurement uncertainties.

Keywords


galaxies: statistics — infrared: galaxies— cosmology: large-scale structure of universe

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