Overview of Uncovered and Suspected Large-Scale Structures behind the Milky Way

Abstract

Various dynamically important extragalactic large-scale structures in the local Universe lie behind the Milky Way. Most of these structures (predicted and unexpected) have only recently been made `visible' through dedicated deep surveys at various wavelengths. The wide range of observational searches (optical, near infrared, far infrared, radio and X-ray) for galaxies in the Zone of Avoidance (ZOA) will be reviewed and the uncovered and suspected large-scale structures summarised. Particular emphasis is given to the Great Attractor region where the existence of yet another cluster is suspected (Woudt 1998). Predictions from reconstructions of the density field in the ZOA are discussed and compared with observational evidence. Although no major structures are predicted out to about v <~ 10; 000 km s-1 for which no observational evidence exists, the comparison between reconstructed density fields and the observed galaxy distribution remain important as they allow derivations of the density and biasing parameters.