Astronomers first observed dark galaxies in the early universe

The astronomers made a series of very long exposures to detect the weak fluorescent glow of dark galaxies.

The team managed to identify some of the properties of dark galaxies.

Scientists used the long-range telescope at Cerro Paranal Observatory in Chile, which managed to detect gas-rich galaxies that do not contain stars.

An international team of astronomers has observed first dark galaxy, an early stage of galaxy formation, said the European Southern Observatory (ESO) from its headquarters in the German city of Garching, to the south.

Scientists used the long-range telescope (VLT, for its acronym in English) Cerro Paranal Observatory in Chile, which managed to detect these gas-rich galaxies that do not contain stars, noting its brightness when illuminated by light of a quasar.

According to Simon Lilly, of the University of Zurich (Switzerland), "the solution to the problem of detecting a dark galaxy was simply to shed some light on it."

"We wanted the fluorescent glow of the gas in galaxies dark when illuminated by ultraviolet light from a quasar close and very bright. The quasar's light makes the dark galaxy is lit in a process similar to what happens when white clothes illuminated with ultraviolet light in a disco, "he said.

In addition, the team of scientists managed to identify some of the properties of dark galaxies, such as the mass of gas contained is about a billion times the mass of the Sun, the stuff of low-mass galaxies rich in gas of the early universe.

"Our observations with the VLT have provided evidence for the existence of compact, isolated dark clouds," said Sebastiano Cantalupo, University of California (USA), author of the study.

He added that the team has "a crucial step to reveal and understand both the dark early stages of galaxy formation, as the process by which they acquired their gas."

The astronomers used the large collecting area and precision of the VLT, with those who carried out a series of very long exposures to detect the weak fluorescent glow of dark galaxies, located a few million light years from the quasar, which, not contain stars, emit little light.