A Comparison of The PSCz and Stromlo-APM Redshift Surveys
Abstract
We present a direct comparison of the clustering properties of two redshift surveys covering a common volume of space: the recently completed IRAS Point Source Catalogue redshift survey (PSCz) containing 14500 galaxies with a limiting flux of 0.6 Jy at 60 microns, and the optical Stromlo-APM survey containing 1787 galaxies in a region of 4300 deg^2 in the southern Galactic cap. We use three methods to compare the clustering properties: the counts-in-cells comparison of Efstathiou (1995), the two-point cross correlation function, and the Tegmark (1998) `null-buster' test. We find that the Stromlo variances are systematically higher than those of PSCz, as expected due to the deficit of early-type galaxies in IRAS samples. However we find that the differences between the cell counts are consistent with a linear bias between the two surveys, with a relative bias parameter b_rel = b_Stromlo/b_PSCz \approx 1.3 which appears approximately scale-independent. The correlation coefficient R between optical and IRAS densities on scales \sim 20 Mpc/h is R > 0.72 at 95% c.l., placing limits on types of `stochastic bias' which affect optical and IRAS galaxies differently.
Keywords
Cite
@article{arxiv.astro-ph/9905182,
title = {A Comparison of The PSCz and Stromlo-APM Redshift Surveys},
author = {M. D. Seaborne and W. Sutherland and H. Tadros and G. Efstathiou and C. S. Frenk and O. Keeble and S. Maddox and R. G. McMahon and S. Oliver and M. Rowan-Robinson and W. Saunders and S. D. M. White},
journal= {arXiv preprint arXiv:astro-ph/9905182},
year = {2009}
}
Comments
Accepted for publication in MNRAS, 13 pages, 18 postscript figures