The redshift space power spectrum of galaxies in a cold dark matter universe

The redshift space power spectrum of dark galaxy halos in a standard cold dark matter (CDM) universe on scales of kh between 0.1/Mpc and 2.5/Mpc is determined. An N-body simulation is evolved to a linear bias factor, b, of 1.0, and groups of particles that are overdense by a factor of about 250 are selected as halos. On the scales that can be investigated in this simulation, the redshift space power spectrum of all the halos has the same shape as the power spectra of the IRAS galaxies and the CfA galaxies and an amplitude that falls between that of the CfA and IRAS galaxies. The power spectrum of halos with masses over 9.8 x 10 exp 12 solar masses agrees well with the power spectrum of IRAS galaxies. If it is assumed that one luminous galaxy would reside in each of the halos, a standard CDM universe that is normalized to the observed cosmic microwave background fluctuations does not predict excessive power in the galaxy distribution on small scales.