As their name suggests, ultradiffuse galaxies, or UDGs, are dwarf galaxies whose stars are spread out over a vast region, resulting in extremely low surface brightness, making them very difficult to detect. Several questions about UDGs remain unanswered: How did these dwarfs end up so extended? Are their dark matter halos—the halos of invisible matter surrounding the galaxies—special?
Click here for original story, Astronomers explain origin of elusive ultradiffuse galaxies
Source: Phys.org