The brightest quasar even seen in the early Universe has been observed with the Hubble Space Telescope. The quasar was identified using a technique called strong gravitational lensing, and it gives a glimpse into how galaxies were born when the Universe was young.
A quasar is a very bright galactic nucleus, a type of supermassive black hole which lies at the center of a galaxy and which is surrounded by a gaseous accretion disk. When the gases in the accretion disk fall towards the black hole because of its gravity, they are heated to very high temperatures and release enormous amounts of energy as visible light and other wavelengths.
The quasar identified by Hubble is called J043947.08+163415.7 and is giving off huge amounts of light. It is as bright as 600 trillion Suns and the supermassive black hole at its center is several hundred million times as massive as our Sun. Scientists were surprised by finding such a bright quasar: “That’s something we have been looking for for a long time,” lead author Xiaohui Fan of the University of Arizona said in a statement. “We don’t expect to find many quasars brighter than that in the whole observable Universe!”
The quasar was identified using a technique called gravitational lensing, which was possible as there is a dim galaxy which is located almost exactly between Earth and the quasar. The gravity of this dim galaxy bends the light emitted by the quasar, making it appear three times larger and fifty times as bright as it would be normally, allowing Hubble to detect it. You can see how the mass of a galaxy in between Earth and an object of observation creates the lensing effect in this video:
The findings are important because they suggest that quasars may produce stars at a much faster rate than previously believed. This particular quasar may be producing up to an incredible 10,000 stars per year, although it is hard to be precise because of the effect of the gravitational lensing. “Its properties and its distance make it a prime candidate to investigate the evolution of distant quasars and the role supermassive black holes in their centers had on star formation,” co-author Fabian Walter of the Max Planck Institute for Astronomy, Germany, explained in a statement.