Creating ultra-diffuse galaxies

Ultra-diffuse galaxies (UDGs) have very low luminosities, comparatively few stars, and little star-formation activity as compared with normal galaxies of similar sizes. Commonly found in galaxy clusters, UDGs come in a wide range of sizes and shapes, many of them being round and smooth like dwarf elliptical galaxies, others showing distorted shapes from having experienced tidal disruptions; some having total masses of as much as one hundred billion solar-masses. In addition to being interesting ...