The power spectrum of the Point Source Catalogue redshift survey

We measure the redshift-space power spectrum P(k) for the recently complete d IRAS Point Source Catalogue (PSC) redshift survey, which contains 14 500 galaxies over 84 per cent of the sky with 60-mu m flux greater than or equa l to 0.6 Jy. Comparison with simulations shows that our estimated errors on P(k) are realistic, and that systematic errors resulting from the finite s urvey volume are small for wavenumbers k greater than or similar to 0.03 h Mpc(-1). At large scales our power spectrum is intermediate between those o f the earlier QDOT and 1.2-Jy surveys, but with considerably smaller error bars; it falls slightly more steeply to smaller scales. We have fitted fami lies of CDM-like models using the Peacock-Dodds formula for non-linear evol ution; the results are somewhat sensitive to the assumed small-scale veloci ty dispersion sigma(v). Assuming a realistic sigma(v) = 300 km s(-1) yields a shape parameter Gamma similar to 0.25 and normalization b sigma(8) simil ar to 0.75; if sigma(v) is as high as 600 km s(-1) then Gamma = 0.5 is only marginally excluded. There is little evidence for any 'preferred scale' in the power spectrum or non-Gaussian behaviour in the distribution of large- scale power.