The Zone of Avoidance

© Kraan-Korteweg & Lahav, 1998, Scientific American 279, p.50

Optical galaxy catalogues become severely incomplete towards the Galactic Equator due to the absorbing dust in the plane of the Milky Way which increasingly reduces the magnitudes and isophotal diameters of external galaxies. In the optical, as much as 20% of the extragalactic sky is obscured by the Galaxy. This incompleteness severely constrains the studies of large-scale structures in the nearby Universe, the gravitational acceleration on the Local Group and other streaming motions, in particular in the region of the Great Attractor. This nearby mass overdensity at (l, b, v) = (320 deg, 0 deg, 4500 km/s) - centered in the Galactic Plane - is largely hidden by the southern Milky Way.

Studying `the Zone of Avoidance' at UCT

Prof. Kraan-Korteweg, Prof. Fairall and Dr. Woudt (all UCT) have been working for many years on unveiling extragalactic large-scale structures behind the southern Milky Way. Particular emphasis is given to the Great Attractor region. As a result of our deep optical galaxy search behind the southern Milky Way, we recognised in 1996 that the Norma cluster (ACO 3627) is the most likely candidate for being the Great Attractor's previously unseen core. Contact Persons in the Department of Astronomy Prof. A.P. Fairall (fairall@physci.uct.ac.za) Dr. P.A. Woudt (pwoudt@artemisia.ast.uct.ac.za) Query Yahoo.com.