The QDOT all-sky IRAS galaxy redshift survey

We describe the construction of the QDOT survey, which is publicly availabl e from an anonymous FTP account. The catalogue consists of infrared propert ies and redshifts of an all-sky sample of 2387 IRAS galaxies brighter than the IRAS PSC 60-mu m completeness limit (S-60 > 0.6 Jy), sparsely sampled a t a rate of one-in-six. At \b\ > 10 degrees, after removing a small number of Galactic sources, the redshift completeness is better than 98 per cent ( 2086/2127). New redshifts for 1401 IRAS sources were obtained to complete t he catalogue; the measurement and reduction of these are described, and the new redshifts tabulated here. We also tabulate all sources at \b\ > 10 deg rees with no redshift so far, and sources with conflicting alternative reds hifts either from our own work, or from published velocities. A list of 95 ultraluminous galaxies (i.e. with L-60 mu m > 10(12) L.) is also provided. Of these, similar to 20 per cent are AGN of some kind; the broad-line objec ts typically show strong Fe II emission. Since the publication of the first QDOT papers, there have been several hundred velocity changes: some veloci ties are new, some QDOT velocities have been replaced by more accurate valu es, and some errors have been corrected. We also present a new analysis of the accuracy and linearity of IRAS 60-mu m fluxes, We find that the flux uncertainties are well described by a combi nation of 0.05-Jy fixed size uncertainty and 8 per cent fractional uncertai nty, This is not enough to cause the large Malmquist-type errors in the rat e of evolution postulated by Fisher et al, We do, however, find marginal ev idence for non-linearity in the PSC 60-mu m flux scale, in the sense that f aint sources may have fluxes overestimated by about 5 per cent compared wit h bright sources. We update some of the previous scientific analyses to assess the changes. T he main new results are as follows. (1) The luminosity function is very wel l determined overall but is uncertain by a factor of several at the very hi ghest luminosities (L-60 mu m > 5 x 10(12) L.), as this is where the remain ing unidentified objects are almost certainly concentrated. (2) The best-fi tting rate of evolution is somewhat lower than our previous estimate; expre ssed as pure density evolution with density varying as (1 + z)(P), we find p = 5.6 + 2.3, Making a rough correction for the possible (but very uncerta in) non-linearity of fluxes, we find p = 4.5 + 2.3. (3) The dipole amplitud e decreases a little, and the implied value of the density parameter, assum ing that IRAS galaxies trace the mass; is Omega = 0.9(+0.45, -0.25). (4) Fi nally, the estimate of density variance on large scales changes negligibly, still indicating a significant discrepancy from the predictions of simple cold dark matter cosmogonies.