Closing the gap: an X-ray selected sample of clusters of galaxies behind the Galactic plane

We discuss the design and current status of the CIZA survey, the first systematic X-ray search for clusters of galaxies in the Galactic plane region. So far, we have compiled a sample of more than 70 X-ray selected clusters at |b|<20 deg, 80% of which were previously unknown. Upon its completion the CIZA cluster catalogue will complement the existing galaxy surveys in the Galactic plane region and allow a fresh look at large-scale structure and local streaming motions.