HIGH-ORDER GALAXY CORRELATION-FUNCTIONS IN THE APM GALAXY SURVEY

We estimate J-point galaxy-averaged correlation functions omega(J)BAR(theta) for J = 2, ..., 9, in a sample of the APM Galaxy Survey with more than 1.3 x 10(6) galaxies and a depth D approximately 400 h-1 Mpc. The hierarchical amplitudes s(J) = omega(J)BAR/omega2(J-1)BAR are roughly constant, up to J = 9, between thetaD approximately 0.5 h-1 Mpc and thetaD approximately 2 h-1 Mpc, and decrease slowly for larger scales. At scales theta(D) > 7 h-1 Mpc, we find strong similarities between the statistical properties of the galaxy fluctuations delta(g) and the theoretical properties of matter fluctuations delta(m) evolving under the influence of gravity in an expanding universe on the assumption that the initial fluctuations are small and Gaussian. This is most easily explained if at large scales there is no significant biasing between matter and galaxy fluctuations, i.e. delta(g) congruent-to delta(m). The comparison of the skewness in the CfA and SSRS catalogues with comparable subsamples of the APM indicates that the volume of a 'fair sample' has to be much larger than the one in the combined CfA/SSRS catalogues.