Astronomers left stunned by ancient quasar as bright as 600trn suns

10 Jan 2019

An artist’s impression of how J043947.08+163415.7, a very distant quasar powered by a supermassive black hole, may look close up. Image: ESA/Hubble, NASA, M Kornmesser

The Hubble Space Telescope couldn’t miss the glare from a powerful quasar found in deep space, and astronomers don’t think they’ll see another one like it.

When it comes to space, cosmic phenomena don’t do things by half or small numbers. When it comes to quasar J043947.08+163415.7, things become almost impossible to comprehend.

First discovered by Maarten Schmidt, quasars are the extremely bright nuclei of active galaxies, created by a supermassive black hole surrounded by an accretion disc. Gas falling towards the black hole releases incredible amounts of energy, which can be observed over all wavelengths.

Now, in a paper published to the The Astrophysical Journal Letters, an international research team spanning five countries was left ‘blinded’ by this recent discovery after 20 years of searching. The unique object is believed to provide insight into the birth of galaxies (which occurred when the universe was less than 1bn years old) and it is one of the brightest ever seen.

Readings from the object show it to have brightness equivalent to 600trn suns (yes, you read that correctly), with the supermassive black hole powering it being several hundred million times as massive as the sun.

Speaking of the find, lead author of the study, Xiaohui Fan of the University of Arizona, said: “That’s something we have been looking for for a long time. We don’t expect to find many quasars brighter than that in the whole observable universe!”

Hubble held the key

Even though you might think it would be impossible to miss, the Hubble Space Telescope was only able to spot it thanks to the recently harnessed ability to observe gravitational lensing.

A dim galaxy is located right between the quasar and Earth, bending the light from the quasar and making it appear three times as large and 50 times as bright as it would be without the effect of gravitational lensing. Even then ground-based telescopes were unable to see it, but thanks to Hubble’s sharp vision it came into view.

The data readings suggest that the supermassive black hole is accreting matter at an extremely high rate, yet the quasar is producing as many as 10,000 stars per year.

Quasars similar to this latest discovery existed during the period of reionisation in the early days of the universe when radiation from young galaxies and quasars reheated the obscuring hydrogen that had cooled off just 400,000 years after the Big Bang. At this point, the universe reverted from a neutral state to being ionised plasma.

The task now for researchers is to find what objects provided the reionising photons, and this discovery may aid that search.

Updated, 5.03pm, 10 January 2019: This article was updated to remove a mistaken reference to Jocelyn Bell Burnell and to clarify that Maarten Schmidt discovered quasars.

Colm Gorey was a senior journalist with Silicon Republic