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.

In this, the first in a series of three papers concerning the SuperCOSMOS Sky Survey (SSS), we give an introduction and user guide to the survey programme. We briefly describe other wide‐field surveys and compare them with our own. We give examples of the data, and make a comparison of the accuracies of the various image parameters available with those from the other surveys providing similar data; we show that the SSS data base and interface offer advantages over these surveys. Some science applications of the data are also described and some limitations discussed. The series of three papers constitutes a comprehensive description and user guide for the SSS.

The UK Schmidt Telescope (UKST) of the Anglo-Australian Observatory completed a narrowband Hα plus [N II] 6548, 6584-Å survey of the Southern Galactic Plane and Magellanic Clouds in late 2003. The survey, which was the last UKST wide-field photographic survey and the only one undertaken in a narrow-band, is now an online digital data product of the Wide-Field Astronomy Unit of the Royal Observatory Edinburgh (ROE). The survey utilized a high specification, monolithic Hα interference bandpass filter of exceptional quality. In conjunction with the fine-grained Tech-Pan film as a detector it has produced a survey with a powerful combination of area coverage (4000 square degrees), resolution (∼1 arcsec) and sensitivity ( 5 Rayleighs), reaching a depth for continuum point sources of R 20.5. The main survey consists of 233 individual fields on a grid of centres separated by 4 • at declinations below +2 • and covers a swathe approximately 20 • wide about the Southern Galactic Plane. The original survey films were scanned by the SuperCOSMOS measuring machine at the Royal Observatory, Edinburgh, to provide the online digital atlas called the SuperCOSMOS Hα Survey (SHS). We present the background of the survey, the key survey characteristics, details and examples of the data product, calibration process, comparison with other surveys and a brief description of its potential for scientific exploitation.

Abstract. We discuss the construction of an X-ray flux-limited sample of galaxy clusters, the REFLEX survey catalogue, to be used for cosmological studies. This cluster identification and redshift survey was conducted in the frame of an ESO key programme and is based on candidates selected from the southern part of the ROSAT All-Sky Survey (RASS). For the first cluster candidate selection from a flux-limited RASS source list, we make use of optical data from the COSMOS digital catalogue produced from the scans of the UK-Schmidt plates. To ensure homogeneity of the sample construction process, this selection is based only on this one well-defined optical data base. The nature of the candidates selected in this process is subsequently checked by a more detailed evaluation of the X-ray and optical source properties and available literature data. The final identification and the redshift is then based on optical spectroscopic follow-up observations. In this paper we document the process by which the primary cluster candidate catalogue is constructed prior to the optical follow-up observations. We describe the reanalysis of the RASS source catalogue which enables us to impose a proper flux limit cut to the X-ray source list without introducing a severe bias against extended sources. We discuss the correlation of the X-ray and optical (COSMOS) data to find galaxy density enhancements at the RASS X-ray source positions and the further evaluation of the nature of these cluster candidates. Based also on the results of the follow-up observations we provide a statistical analysis of the completeness and contamination of the final cluster sample and show results on the cluster number counts. The final sample of identified X-ray clusters reaches a flux limit of 3 10 −12 erg s −1 cm −2 in the 0.1-2.4 keV band and comprises 452 clusters in an area of 4.24 ster. The results imply a completeness of the REFLEX cluster sample well in excess of 90%. We also derive for the first time an upper limit of less than 9% for the number of clusters which may feature a dominant contribution to the X-ray emission from AGN. This accuracy is sufficient for the use of this cluster sample for cosmological tests.

In this, the second in a series of three papers concerning the SuperCOSMOS Sky Survey, we describe the methods for image detection, parametrization, classification and photometry. We demonstrate the internal and external accuracy of our object parameters. Using examples from the first release of data, the South Galactic Cap survey, we show that our image detection completeness is close to 100 per cent to within ∼1.5 mag of the nominal plate limits. We show that for the BJ survey data, the image classification is externally > 99 per cent reliable to BJ∼19.5. Internally, the image classification is reliable at a level of > 90 per cent to BJ∼21, R∼19. The photometric accuracy of our data is typically ∼0.3 mag with respect to external data for m>15. Internally, the relative photometric accuracy in restricted position and magnitude ranges can be as accurate as ∼5 per cent for well‐exposed stellar images. Colours are externally accurate to σB−R,R−I∼0.07 at BJ∼16.5, rising to σB−R,R−I∼0.16 at BJ∼20.

In this, the third in a series of three papers concerning the SuperCOSMOS Sky Survey, we describe the astrometric properties of the data base. We describe the algorithms employed in the derivation of the astrometric parameters of the data, and demonstrate their accuracies by comparison with external data sets using the first release of data, the South Galactic Cap survey. We show that the celestial coordinates, which are tied to the International Celestial Reference Frame via the Tycho–2 reference catalogue, are accurate to better than ±0.2 arcsec at J,R∼19,18, rising to ±0.3 arcsec at J,R∼22,21, with positional‐dependent systematic effects from bright to faint magnitudes at the ∼0.1‐arcsec level. The proper motion measurements are shown to be accurate to typically ±10 mas yr−1 at J,R∼19,18, rising to ±50 mas yr−1 at J,R∼22,21, and are tied to zero using the extragalactic reference frame. We show that the zero‐point errors in the proper motions are ≤1 mas yr−1 for R>17, and are no larger than ∼10 mas yr−1 for R<17 mas yr−1.

We report the first results of a spectroscopic survey of galaxies in the core of the Shapley Concentration, the richest nearby supercluster of clusters of galaxies. We have measured 311 new galaxy redshifts in an area of ∼ 4.5 square degrees centered around the Abell cluster A3558. Considering also the data already available in the literature, the total number of galaxy redshifts in this area amounts to more than 500.On the basis of these data we estimate the mean velocities and the velocity dispersions of the Abell clusters A3556, A3558 and the poor cluster SC 1329 -314. Finally, from an analysis of the projected and three-dimensional distributions of galaxies in this region, we estimate the galaxy overdensity and find that the core of the Shapley Concentration has an interesting, very complex dynamical state: the main clusters appear to be interacting with each other, forming a single elongated structure containing many subcondensations.

The optical spectrum and light curve of EC13471–1258 show that it is an eclipsing binary with an orbital period of 3h 37m comprising a DA white dwarf and a dMe dwarf. Total eclipses of the white dwarf are observed lasting 14 min, with the partial phases lasting 54 s. On one occasion, two pre‐eclipse dips were seen. Timings of the eclipses over 10 yr show jitter of up to 12 s. Flares from the M dwarf are regularly observed. The M dwarf also shows a large‐amplitude ellipsoidal modulation in the V‐band light curve. The component stars emit almost equal amounts of light at 5500 Å. Hubble Space Telescope (HST) STIS spectra show strong Lyman‐α absorption with weak metal lines of C i,ii and Si ii superimposed. Model atmosphere analysis yielded an effective temperature of 14 220 ± 300 K and log g of 8.34 ± 0.20 for the white dwarf with these errors being strongly correlated. Its metal abundance is 1/30th solar with an uncertainty of 0.5 dex, and it is rapidly rotating with V1 sin i= 400 ± 100 km s−1. The white dwarf also shows radial velocity variations with a semi‐amplitude of 138 ± 10 km s−1. The gravitational redshift of the white dwarf was measured as 62 km s−1. From optical spectroscopy the spectral type of the M dwarf was found to be M3.5–M4, its temperature 3100 ± 75 K, its rotational velocity 140 ± 10 km s−1, its radial velocity semi‐amplitude 266 ± 5 km s−1, its mean V−I colour 2.86 and its absolute V magnitude 11.82. Intriguingly, its metal abundance is normal solar. The Hα emission line shows at least two distinct components, one of which is uniformly distributed around the centre of mass of the M dwarf and provided the estimate of the rotational velocity of the M dwarf. The other arises from the other side of the binary centre of mass, well within the white dwarf Roche lobe. This behaviour is confirmed by Doppler tomography, which shows the presence of two distinct velocity components within the primary Roche lobe. The interpretation of these features is uncertain. Variations in strength of the components with binary phase can be attributed to optical thickness in the Balmer lines. Similar behaviour is seen in the observations of the other Balmer emission lines, although with a poorer signal‐to‐noise ratio. Flares in Hα were observed and are consistent with arising from the vicinity of the M dwarf. Dynamical solutions for the binary are discussed and yield an inclination of 75.5°± 2.0o, a white dwarf mass and radius of 0.78 ± 0.04 M⊙ and 0.011 ± 0.01 R⊙, and an M dwarf mass and radius of 0.43 ± 0.04 M⊙ and 0.42 ± 0.02 R⊙. These parameters are consistent with the Wood mass–radius relation for white dwarfs and the Clemens et al. mass–radius relation for M dwarfs; we argue that the M dwarf just fills its Roche lobe. The radius of the white dwarf and the model fit imply a distance of 48 ± 5 pc and an absolute V magnitude of 11.74. The rapid rotation of the white dwarf strongly suggests that the system has undergone mass transfer in the past, and implies that it is a hibernating cataclysmic variable. The...