Abstract. We present the catalogue of the REFLEX Cluster Survey providing information on the X-ray properties, redshifts, and some identification details of the clusters in the REFLEX sample. The catalogue describes a statistically complete X-ray flux-limited sample of 447 galaxy clusters above an X-ray flux of 3 × 10 −12 erg s −1 cm −2 (0.1 to 2.4 keV) in an area of 4.24 ster in the southern sky. The cluster candidates were first selected by their X-ray emission in the ROSAT-All Sky Survey and subsequently spectroscopically identified in the frame of an ESO key programme. Previously described tests have shown that the sample is more than 90% complete and there is a conservative upper limit of 9% on the fraction of clusters with a dominant X-ray contamination from AGN. In addition to the cluster catalogue we also describe the complete selection criteria as a function of the sky position and the conversion functions used to analyse the X-ray data. These are essential for the precise statistical analysis of the large-scale cluster distribution. This data set is at present the largest, statistically complete X-ray galaxy cluster sample. Together with these data set we also provide for the first time the full three-dimensional selection function. The sample forms the basis of several cosmological studies, one of the most important applications being the assessment of the statistics of the large-scale structure of the universe and the test of cosmological models. Part of these cosmological results have already been published.

We have identified a new Lyman limit absorption system towards PKS1937−1009, with log N(H i) = 18.25 ± 0.02 at z= 3.256 that is suitable for measuring deuterium/hydrogen (D/H). We find a 68.3 per cent confidence range for D/H of 1.6+0.25−0.30× 10−5 and a 95.4 per cent range of 1.6+0.5−0.4× 10−5. The metallicity of the cloud where D/H was measured is low, [Si/H]=−2.0 ± 0.5. At these metallicities we expect that D/H will be close to the primordial value. Our D/H is lower than the D/H value predicted using the Ωb calculated from the cosmic background radiation measured by the Wilkinson Microwave Anisotropy Probe, 2.60+0.19−0.17× 10−5. Our result also exacerbates the scatter in D/H values around the mean primordial D/H.

We present an estimate of the bolometric X‐ray luminosity–velocity dispersion (Lx–σv) relation measured from a new, large and homogeneous sample of 171 low‐redshift, X‐ray selected galaxy clusters. The linear fitting of log(Lx)–log(σv) gives Lx= 1032.72±0.08σ4.1 ± 0.3v erg s−1h−250. Furthermore, a study of 54 clusters, for which the X‐ray temperature of the intracluster medium T is available, allows us to explore two other scaling relations, Lx–T and σv–T. From this sample we obtain Lx∝T3.1±0.2 and σv∝T1.00±0.16, which are fully consistent with the above result for Lx–σv. The slopes of Lx–T and σv–T are incompatible with the values predicted by self‐similarity (Lx∝T2∝σ4v), thus suggesting the presence of non‐gravitational energy sources heating up the intracluster medium, in addition to the gravitational collapse, in the early stages of cluster formation. On the other hand, the result on log(Lx)–log(σv) supports the self‐similar model.

We present the final data from the spectroscopic survey of the ROSAT-ESO Flux-Limited X-ray (REFLEX) catalog of galaxy clusters. The REFLEX survey covers 4.24 steradians (34% of the entire sky) below a declination of δ = +2.5 0 and at high Galactic latitude (|b| > 20 • ). The REFLEX catalog includes 447 entries with a median redshift of 0.08 and is better than 90% complete to a limiting flux f X = 3 × 10 −12 erg s −1 cm −2 (0.1 to 2.4 keV), representing the largest statistically homogeneous sample of clusters drawn from the ROSAT All-Sky Survey (RASS) to date. Here we describe the details of the spectroscopic observations carried out at the ESO 1.5 m, 2.2 m, and 3.6 m telescopes, as well as the data reduction and redshift measurement techniques. The spectra typically cover the wavelength range 3600-7500 Å at a two-pixel resolution of ∼14 Å, and the measured redshifts have a total rms error of ∼100 km s −1 . In total we present 1406 new galaxy redshifts in 192 clusters, most of which previously did not have any redshift measured. Finally, the luminosity/redshift distributions of the cluster sample and a comparison to the no-evolution expectations from the cluster X-ray luminosity function are presented.