Science & Technology

Most distant source of radio emission discovered, holds clues about ancient universe

It took 13 billion years for the quasar’s light to reach earth

By DTE Staff
Published: Monday 08 March 2021
Most distant source of radio emission discovered. Photo: ESO/M. Kornmesser
An artist's rendition of the most distant quasar which is not as 'radio-loud' as the new discovery An artist's rendition of the most distant quasar which is not as 'radio-loud' as the new discovery

An international team of astronomers have discovered the most distant ‘radio-loud’ quasar with the help of European Southern Observatory’s Very Large Telescope (ESO’s VLT). It took 13 billion years for the quasar’s light to reach earth, according to a paper published in The Astrophysical Journal March 8, 2021.

Quasars are very luminous objects in faraway galaxies that emit jets at radio frequencies. They are only found in galaxies that have supermassive blackholes which power these bright discs. However, 90 per cent of them do not emit strong radio waves, making this newly-discovered one special.

Most active galaxies have a supermassive black hole at the centre which sucks in surrounding objects. Quasars are formed by the energy emitted by materials spiralling around a blackhole right before being sucked into it.  

Named P172+18, the quasar emitted wavelengths which had a redshift of 6.8. Only three other ‘radio-loud’ sources with redshift greater than six have been discovered so far and the most distant one had a redshift of 6.18. The higher the redshift of the radio wavelength, the farther away is the source.

Moreover, this particular quasar appears to the scientists as it was when the universe was just around 780 million years old. The glowing disc around a blackhole 300 million times more massive than our Sun, thus, holds clues about the ancient star systems and astronomical bodies.

It is also one of the fastest accreting quasars, which means it is accumulating objects from the galaxy at an enormous speed. This has led team that discovered it to infer that the blackhole at its centre is consuming from its galaxy at a stunning rate.

Chiara Mazzucchelli, fellow at ESO in Chile, who led the discovery with Eduardo Bañados of the Max Planck Institute for Astronomy in Germany, said:

The black hole is eating up matter very rapidly, growing in mass at one of the highest rates ever observed.”

The scientists think that the powerful radio jets shooting out of the quasar fuelled the appetite of the blackhole. “The jets are thought to be capable of disturbing the gas around the black hole, increasing the rate at which gas falls in,” a press statement from ESO explained.

A detailed study of these ‘radio-loud’ superbright objects can lead astronomers to understanding how the supermassive blackholes in their core grew to be as big so rapidly since the Big Bang.

The team believes that more such quasars that tell stories about the ancient universe will be found, perhaps even farther away from earth.

Subscribe to Daily Newsletter :

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.