IRAS GALAXIES AND THE LARGE-SCALE STRUCTURE IN THE CFA SLICE

A first assay is made at comparing the relative spatial distributions of IRAS and optical galaxies in the CfA slice. Based on our color criteria, we find 241 IRAS galaxies in the slice region. Redshifts have been identified for 72% of the galaxies. We examine the angular and the spatial correlation functions as well as the void probability functions for the two samples. In general, IRAS galaxies are less clustered than optical galaxies. However, we find that the distribution of IRAS galaxies is essentially identical to that of late-type optical galaxies. Furthermore, we find that the discrepancy between the clustering properties of the IRAS and optical samples in the CfA slice region is entirely due to the paucity of IRAS galaxies in the core of the Coma cluster. The spatial distributions for the IRAS and the optical galaxies, both late and early types, outside the dense core of the Coma cluster are entirely consistent with each other, in conflict with the predictions of the linear (constant) biasing scenario. In the field, the optical galaxies trace the mass as well as the IRAS galaxies.