A comparison of the PSCz and Stromlo -- APM redshift surveys

Autor: William J. Sutherland, M. Seaborne, Richard G. McMahon, Simon D. M. White, George Efstathiou, Will Saunders, Carlos S. Frenk, Steve Maddox, Sebastian Oliver, Helen Tadros, O. Keeble, M. Rowan-Robinson
Rok vydání: 1999
Předmět:
Zdroj: Scopus-Elsevier
ISSN: 1365-2966
0035-8711
DOI: 10.1046/j.1365-8711.1999.02796.x
Popis: 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.
Accepted for publication in MNRAS, 13 pages, 18 postscript figures
Databáze: OpenAIRE
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