HIGHER-ORDER CORRELATIONS OF IRAS GALAXIES

We derive the higher order irreducible angular correlation functions, up to the eight-point function, for a sample of 4654 IRAS galaxies, flux-limited at 1.2 Jy in the 60-mu-m band. The correlations are generally found to be somewhat weaker than those for the optically selected galaxies, consistent with the visual impression of looser clusters in the IRAS sample. We find that the N-point correlation functions can be expressed as the symmetric sum of products of N - 1 two-point functions, although the correlations above the four-point function are consistent with zero. The coefficients are consistent with the hierarchical clustering scenario as modeled by Hamilton and by Schaeffer, although for v almost-equal-to - 1, and with the predictions of secondary infall.