Strong gravitational lensing is an extremely powerful tool to go beyond the current limits in angular resolution and to investigate the high-redshift, i.e. distant Universe. Scientists at MPA take advantage of this phenomenon to perform a detailed study of 17 Lyman-α-galaxies and present an analysis of the sizes and star formation rates of their reconstructed ultra-violet (UV) continuum emission.
Previous studies of large AGN samples both a low and at high redshifts seemed to rule out galaxy mergers as the drivers for black hole growth. A new technique developed at MPA for selecting a rare type of active galactic nuclei now show that it is possible to identify a new class of AGN in which more than 80% of the galaxies turn out to be merging or interacting systems, with clear indications of an accreting black hole. A detailed statistical analysis then reveals that mergers drive black hole formation in the most massive galaxies in the local Universe.