The UK ROSAT Deep Survey
ASTRON NACHR 319:1-2 (1998) 51-54
Abstract:
We present a summary of the identification content of the UK ROSAT Deep Survey. The survey is based on a 115ksec PSPC observation and comprises a sample of 70 sources to a flux limit of 2 x 10(-15) ergs cm(-2) s(-1) (0.5-2 keV). At bright fluxes the survey is dominated by broad line QSOs, at intermediate fluxes it contains a number of groups and clusters of galaxies, but at faint fluxes the survey contains many galaxies with narrow optical emission lines (NELGs). The average X-ray spectrum of the NELGs is harder than that of the QSOs and similar to that of the X-ray background. The NELGs have optical spectra similar to the majority of the field galaxy population in the same redshift range and may simply be the more luminous members of the emission line field galaxy population. Based on optical line ratios and X-ray/optical ratios, the NELGs, both as a sample and within individual galaxies, appear to be a mixture of starburst galaxies and true AGN.The origin of the cosmic soft X-ray background: optical identification of an extremely deep ROSAT survey
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 295:3 (1998) 641-671
Measuring frequency response of surface-micromachined resonators
Proceedings of SPIE SPIE, the international society for optics and photonics 3225 (1997) 32-43
The APM galaxy survey - V. Catalogues of galaxy clusters
Monthly Notices of the Royal Astronomical Society 289:2 (1997) 263-284
Abstract:
We describe the construction of catalogues of galaxy clusters from the APM Galaxy survey using an automated algorithm based on Abell-like selection criteria. We investigate the effects of varying several parameters in our selection algorithm, including the magnitude range and radius from the cluster centre used to estimate the cluster richnesses. We quantify the accuracy of the photometric distance estimates by comparing them with measured redshifts, and we investigate the stability and completeness of the resulting catalogues. We find that the angular correlation functions for different cluster catalogues are in good agreement with one another, and are also consistent with the observed amplitude of the spatial correlation function of rich clusters. © 1997 RAS.X-ray QSO evolution from a very deep ROSAT survey
Monthly Notices of the Royal Astronomical Society 285:3 (1997) 547-560