The Spatial Distribution of Emission-Line Galaxies

Abstract

Galaxy redshift surveys carried out over the last decade have revealed that bright galaxies are organized in sheets and filaments enclosing large empty regions, the voids, which occupy more than 80 per cent of the whole space. Still under debate is the question whether all galaxies follow this non-uniform distribution or if less luminous galaxies are more equally distributed. From an observer’s point of view, the emptiness of the voids may be a result of observational bias. From the theoretical point of view, there has been the prediction (e.g.,Kaiser 1986, Bardeen 1986) that luminous galaxies were formed preferentially in high-density regions of the Universe, thus giving us a biased view of the large-scale distribution of matter.