PURE LUMINOSITY EVOLUTION HYPOTHESIS FOR QSOS - FROM LUMINOSITY FUNCTIONS TO SIMULATED CATALOGS

This paper describes the construction of realistic extragalactic Monte -Carlo catalogues, aimed at comparing the behaviour of cosmological te sts as a function of various parameters. An input luminosity function is required to simulate QSO catalogues: it is derived from data throug h an arbitrary choice of cosmological and evolutionary models. A due a ttention must be paid to the computation of individual maximum volumes in complete (magnitude- and redshift-limited) samples. Details of thi s computation are examined for the case of strong luminosity evolution . The values of the evolution parameter are derived for various cosmol ogies, corresponding to < V/V-max >= 1/2 in the sample of 400 Ultra-Vi olet Excess (UVX) QSOs (Boyle et al., 1990). The various luminosity fu nctions are compared, both for the whole sample and in redshift bins. A characteristic evolution time is defined and computed, depending str ongly on the cosmology, but practically constant when expressed in ter ms of the age of the universe. Algorithms are given for producing cata logues based on the simple hypothesis that the objects are uniformly d istributed in volume but suffer pure luminosity evolution. The only in put based on real data is the luminosity function, but this requires n either a redshift nor an apparent magnitude histogram. Simulated redsh ift and absolute magnitude histograms are compared to real data.