In Big Bang cosmology, reionization is the process that reionized the matter in the universe after the "dark ages," and is the second of two major phase transitions of gas in the universe. As the majority of baryonic matter is in the form of hydrogen, reionization usually refers to the reionization of hydrogen gas. The primordial helium in the universe experienced the same phase changes, but at different points in the history of the universe, and is usually referred to as helium reionization.
Astronomers have discovered the most distant quasar known so far, dubbed ULAS J1120+0641, powered by a supermassive black hole with a mass 2 billion times that of our sun – it’s also the brightest object in the known Universe. At a redshift of 7.1, placing it at only 770 million years after the Big Bang, the newly discovered [...]