Clustering in the 1.2-Jy IRAS Galaxy Redshift Survey - I. The redshift and real space correlation functions*

We present analyses of the two-point correlation function derived from an all-sky redshift survey of 5313 galaxies extracted from the Infrared Astronomical Satellite (IRAS) data base. The redshift space correlation function |$\xi(s)$| is well described by a power law, |$\xi(s)=(s/4.53 \ h^{-1} \ {\rm Mpc})^{-1.28}$|⁠, on scales |$\lesssim 20 \ h^{-1} \ {\rm Mpc}$|⁠; on larger scales |$\xi(s)$| drops below the extension of this power law. We examine the effect of redshift space distortions on the correlation function and compute the full 2D correlation function |$\xi(r_p, \pi)$|⁠. From this we drive the real space correlation function, which is well deecribed by |$\xi(r)=(r/3.76 \ h^{-1} \ {\rm Mpc})^{-1.66}$| on scales |$\lesssim 20 \ h^{-1} \ {\rm Mpc}$| The derived correlation functions are found to be consistent with previous determinations in the literature, and seem to show more power on large scales than predicted by the standard cold dark matter(CDM) model. Comparison of the derived |$\xi(r)$| with the correlation function of optical galaxies implies on optical-to-IRAS bias ratio of |$b_0/b_1=1.38\pm0.12$| on a scale of |$\sim 8 \ h^{-1} \ {\rm Mpc}$|⁠. The variences in cubical cells inferred from |$\xi(s)$| appear to be discrepant with the results previously reported by Efstathiou et al.