Reconstructing PSCz with a Generalized PIZA

Abstract

We present a generalized version of the Path Interchange Zel'dovich Approximation (PIZA; Croft and Gaztanaga 1997; hereafter CG97), which may be used to reconstruct density and velocity fields from realistic galaxy redshift surveys. The original PIZA does not include the possibility of using galaxies in redshift space with a selection function. We map galaxy positions from redshift to real space and from the Local Group rest frame to the CMB rest frame. To take account of the selection function, we minimize the mass-weighted action. We apply our new method to mock galaxy catalogues and find it offers an improvement in reconstructions over linear theory. Applying PIZA to the PSCz we can obtain real space density, initial density, and peculiar velocity fields, bulk velocities and the dipole. Comparison of our reconstructed dipole with the CMB dipole gives beta=0.6