Quasars are the most luminous galaxies in the Universe, although they appear very faint because they are extremely distant. At their center they host a supermassive black hole, many of them up to a billion solar masses. The matter they attract and fall in these regions of space causes huge explosions, which is why these objects are so bright. Now, an international team of astronomers has announced the discovery of the most distant quasar known, or what is the same, the oldest. It existed more than 13 billion years ago, just 670 million years after the Big Bang. This monster is a thousand times brighter than the Milky Way and feeds the one that would also turn out to be the (so far) first supermassive black hole of the universe, which weighs more than 1.6 billion times the mass of the Sun.
Quasars are the most energetic objects in the universe. They form when gas in the superheated accretion disk around a supermassive black hole is inexorably drawn inward, radiating light across the electromagnetic spectrum. The amount of energy emitted by these objects is enormous, and the most massive examples easily outnumber entire galaxies.
The newly discovered quasar, named J0313-1806, has been unveiled at the American Astronomical Society (AAS) meeting. The study has been accepted into The Astrophysical Journal Letters and is available in pre-printed format at arXiv.org. Very distant, it has a redshift of z = 7.64.
“The more distant quasars are crucial to understanding how the first black holes formed and cosmic reionization, the last great phase transition in our universe,” says Xiaohui Fan, a co-author of the study and a professor of astronomy at the University of Arizona.
The presence of such a massive black hole so early in the history of the universe challenges the theories of the formation of these giants. “Black holes created by the first massive stars could not have grown so large in a few hundred million years,” says Feige Wang, a member of NASA’s Hubble team at the University of Arizona and lead author of the research paper.
The observations that led to this discovery were made using a variety of observatories around the world, including several telescopes in Hawaii. Data from the Pan-STARRS1 observatory and UKIRT Hemisphere Survey helped identify J0313-1806 first. Once the team confirmed its identity as a quasar, they obtained high-quality spectra from the Keck Observatory and Gemini North to measure the mass of the central supermassive black hole.
“Measuring the spectral lines that originate from the gas surrounding the accretion disk of the quasar allows us to determine the mass of the black hole and study how its rapid growth influences its environment,” says Aaron Barth, Professor of Physics and Science. Astronomy at the University of California at Irvine.
“Observing infrared light requires low temperatures. The almost icy climate that prevails at the summit of Maunakea (4,205 m) makes it one of the only places on Earth with instruments sensitive enough to observe such red wavelengths, “says Joe Hennawi, professor at the University of California Santa Barbara who helped run the observations with the Keck / NIRES spectrograph.
In addition to weighing the monstrous black hole, observations from the Keck Observatory and Gemini North discovered an extremely fast outflow emanating from the quasar in the form of a wind traveling at 20% the speed of light. “The energy released by such an extreme high-speed outflow is large enough to impact star formation throughout the quasar’s host galaxy,” says Jinyi Yang of the University of Arizona Steward Observatory.
This is the first known example of a quasar sculpting the growth of its host galaxy, making J0313-1806 a promising target for future observations. The galaxy that hosts it is experiencing a star-forming outbreak, producing new stars 200 times faster than the Milky Way. The combination of this intense star formation, the luminous quasar, and the high-speed outflow make J0313-1806 and its host galaxy a promising natural laboratory for understanding the growth of supermassive black holes and their host galaxies in the early universe.