The Bright SHARC Survey: The Selection Function and Its Impact on the Cluster X‐Ray Luminosity Function

ABSTRACT – 2 – We present the results of a comprehensive set of simulations designed to quantify the selection function of the Bright SHARC survey (Romer et al. 2000a) for distant clusters. The statistical significance of the simulations relied on the creation of many thousands of artificial clusters with redshifts and luminosities in the range 0.25 < z < 0.95 and 0.5 < LX < 10 × 10 44 erg s −1 (0.5−2.0 keV). We created 1 standard and 19 varied distribution functions, each of which assumed a different set of cluster, cosmological and operational parameters. The parameters we varied included the values of Ω0, ΩΛ, β, core radius (rc) and ellipticity (e). We also investigated how non-standard surface brightness profiles (i.e the Navarro, Frenk & White 1997, NFW, model); cooling flows; and the ROSAT pointing target, influence the selection function in the Bright SHARC survey. For our standard set we adopted the parameters used during the derivation of the Bright SHARC Cluster X-ray Luminosity Function (CXLF, Nichol et al. 1999, N99), i.e. Ω0 = 1, ΩΛ=0 and an isothermal β model with β=0.67, rc=250 kpc and e = 0.15. We found that certain parameters have a dramatic effect on our ability to