Quasars are regions around powerful supermassive black holes that outshine the light of their host galaxy. Being so bright, quasars are some of the more distant objects we have ever found, and now an international team has discovered 63 new such objects from the first billion years of the universe.
"Quasars are among the brightest objects and they literally illuminate our knowledge of the early universe," lead author Eduardo Bañados, from the Carnegie Institution of Science in Washington DC, said in a statement.
These new quasars were discovered by the Pan-STARRS survey in Hawaii, which had previously discovered 77 other early universe quasars. The entire set of 140 objects was presented in a paper that is available online, and will be published in The Astrophysical Journal Supplement Series.
The team considers the data release as pivotal in our understanding of the early universe, which remains a very mysterious epoch and is aptly nicknamed the "cosmic dark ages". Having such a large number of objects allows for robust statistical analysis of these objects, and the researchers hope it will provide an insight into how the first galaxies came to be.
"The formation and evolution of the earliest light sources and structures in the universe is one of the greatest mysteries in astronomy," Bañados said.
"Very bright quasars such as the 63 discovered in this study are the best tools for helping us probe the early universe. But until now, conclusive results have been limited by the very small sample size of ancient quasars."
It took hundreds of millions of years after the Big Bang for the first stars and galaxies to start shining. Astronomers believe that hydrogen gas fell into the gravitational wells created by dark matter and, under the action of gravity, the gas condensed into the first stars, and over time into the first galaxies.
This type of survey, and upcoming instruments like the James Webb Space Telescope, will help in pushing the limits on how far we can see in the past, and hopefully find out what actually happened in the cosmic dark ages.