Astronomers just discovered a Starless Galaxy

Astronomers have discovered six possible "dark galaxies" - galaxies that, instead of being filled with an abundance of stars, do not seem to have many, if any.

According to the most recent astrophysical models, the initial galaxies could have gone through a dark phase. These dark galaxies, already quite large and full of gas, may have had problems forming stars. Finding these galaxies is extremely challenging, since they do not emit light, but using light from nearby sources, researchers believe they have seen six of them.

As reported in the Astrophysical Journal, European researchers identified these six candidate objects in this category of galaxy that existed when the universe was not even 2 billion years old. The objects were fluorescently illuminated by nearby quasars, active galaxies fueled by the accretion of material falling into a supermassive black hole. This process makes the quasars terribly bright, but conveniently, its light can be used to look at other objects like a flashlight.

Quasars emit a huge amount of ultraviolet light, which is then absorbed by the gas and re-emitted. In a way, it is similar to how white clothing shines under a black (ultraviolet) light. And these observations are enough for astronomers to discover many properties of these galaxies.

The six candidates for the dark galaxy are small, compact objects, estimated to weigh between 200 million and 6 billion times the mass of our Sun. According to the researchers, they have similar properties to other dark galaxies that have been discovered in recent years, which makes them good candidates. The previously discovered ones are newer than the new suspects, being there 3 billion years after the Big Bang, so a billion years more than these newly discovered objects. Discovering older dark galaxies can shed light on the early universe and the formation of galaxies.

Despite the new and very interesting observations, dark galaxies remain a complex class of objects within the zoo of cosmic evolution. The universe's few billions of years still lack broad and profound observations due to the limitation of our current observational instruments. New telescopes, such as the James Webb Space Telescope, and dedicated research will help fill in the gaps, and maybe soon these dark galaxies will not be so mysterious. 

[ IFLS ]