A MASSIVE Z=0.088 SUPERCLUSTER AND TESTS OF STARBURST GALAXY EVOLUTION AT THE NORTH ECLIPTIC POLE

We present redshifts and luminosities for galaxies in a very deep IRAS field around the north ecliptic pole region (NEPR). The redshift data set consists of 76 sources drawn from co-added and point source filte red IRAS scans of the pole region with 60 mu m flux densities bounded between 210 and 50 mJy. This is, tberefore, the deepest flux-limited f ar-infrared sample yet assembled: it extends out to a median redshift of z = 0.080. The sample is strongly clustered in redshift space, with one very strong concentration at z = 0.088, and at least four weaker clusters. The observed portion of the z = 0.088 cluster has a surface density of galaxies more than three times as dense as the Great Wall. This is the deepest far-infrared selected sample yet to become availab le for tests of starburst galaxy evolution. We have compared the redsh ift distribution of a subsample to evolutionary models and find the da ta consistent with either mild (L proportional to [1 + z](1-2)) lumino sity evolution, mild (rho proportional to [1 + z](1-2)) comoving densi ty evolution, or no evolution. It is difficult, however, to distinguis h between true evolution and the effects of large-scale structure in a sample of this size.