Predicted in theory but never before observed, these elusive objects appear to be similar to today’s galaxies in that they’re rich in gas. However, without any stars to light the gas, the galaxies have remained hidden from view.
For instance, without stars, the Milky Way‘s famous, gas-rich Orion Nebula would be dark to our telescopes, said study leader Sebastiano Cantalupo, an astronomer at University of California, Santa Cruz.
To find these cosmic ghosts, Cantalupo and colleagues took advantage ofÂ one of the brightest light sources in the cosmosâ€”a quasar known as HE0109-3518.
A superbright galaxy 11 billion light-years away, the quasar shines with the power of a hundred trillion suns and can light up its galactic neighborhood to a radius of ten million light-years. Quasars areÂ very distant galaxies that have actively feedingâ€”and rapidly rotatingâ€”supermassive black holes at their hearts.