A large population of ultra-compact dwarf galaxies in the Hydra I cluster I. Misgeld, S. Mieske, M. Hilker, T. Richtler, I. Y. Georgiev and Y. Schuberth A&A, 531 (2011) A4 Published online: 30 May 2011 DOI: 10.1051/0004-6361/201116728