1994 · 35 citations · 0 references
Natural SciencesAstronomyPhysicsAstrophysicsX-ray AstronomyExtragalactic X-ray SourcesX-ray Background RadiationX-ray OpticsX-ray Source CatalogsX-ray SpectroscopyX-ray TelescopesAstronomical X-ray DetectionFundamental AstronomySoft X-ray AstronomyX-ray Background SpectrumX-ray Source DetectionX-ray Survey TelescopesX-ray Surveys