Radio Galaxy Zoo
As supermassive black holes in the centers of galaxies consume their surrounding material, large amounts of radio synchrotron emission is released in the form of radio jets. These galaxies are called radio galaxies. Through Radio Galaxy Zoo, citizen scientists have helped assemble one of the largest catalogues of radio galaxy classifications and discovered many more radio galaxies with unusual morphologies. The picture on the left shows one of the earliest discoveries made by Radio Galaxy Zoo citizen scientists, a giant wide-angle tailed galaxy which in turn revealed a previously uncatalogued cluster of galaxies (named the Matorny-Terentev cluster after the citizen scientists who first made this discovery; Banfield et al 2016).