Scientists noticed the dark galaxies in an image of the sky around the quasar HE0109-3518, whose energetic radiation causes its surroundings to glow. A quasar is defined as a massive and extremely remote celestial object, emitting exceptionally large amounts of energy, and typically having a starlike image in a telescope. It has been suggested that quasars contain massive black holes and may represent a stage in the evolution of some galaxies.
The dark galaxies contain few, if any, stars and show up as shadows from around 12 billion light-years away, which is amazing considering that the universe is estimated to be 13.8 billion years old, with the oldest star being 13.2 billion years. The dark galaxies can’t be seen directly, but clues to their existence are buried in the light around them, making it possible, yet difficult, for the physicists at ETH Zurich to identify and study the immense clouds of primeval gas and rocky debris. This is important because their analysis could help us learn more about the mysteries around the creation of stars and galaxies.
Because it’s so challenging to find and identify the dark galaxies, it’s necessary to use advanced technology. In this case, scientists worked with the MUSE telescope. A similar discovery was made in 2012, but research was limited given the instruments available at the time. Since then, an upgrade to the European Southern Observatory’s Very Large Telescope has absolutely helped astronomers to look closer at time and space than has ever been possible before. Seen below is the MUSE, or Multi Unit Sectroscopic Explorer, which has played a large role in the recent findings.
Twitter - @sterrenkunde