Astronomers find elusive supermassive black holes cloaked in dust from Cosmic Dawn

An artist’s illustration of a quasar hidden by dust in the early universe. (Image: NAOJ)

Astronomers have made a striking discovery from Cosmic Dawn. Seven supermassive black hole-powered quasars were found, hidden beneath veils of dust. This period dates back less than a billion years.

How Were Hidden Quasars Detected?

The team combined Subaru Telescope’s wide survey and James Webb Space Telescope’s infrared vision. This dual approach proved essential for spotting the elusive quasars. Yoshiki Matsuoka of Ehime University said the strategy was key.

The Subaru Telescope first identified unusually bright galaxies. These galaxies showed high-energy emissions but lacked visible quasar signatures. Using JWST’s Near Infrared Spectrograph, astronomers then examined these galaxies in infrared. This allowed them to see through the obscuring cosmic dust.

What Makes These Quasars Special?

Seven galaxies revealed unmistakable signs of active quasars. Each quasar emitted energy equal to several trillion suns. They were powered by black holes billions of times larger than our sun.

The surrounding dust absorbed nearly all ultraviolet light. About 99.9% of ultraviolet light was blocked, and 70% of visible light. This extreme shrouding explains why these quasars remained hidden until now.

How Does This Change Understanding of Cosmic Dawn?

The discovery suggests shrouded quasars are as common as visible ones. Previously, scientists thought fewer existed at Cosmic Dawn. Now, the team estimates there are twice as many.

Supermassive black holes shape galaxy formation and cosmic evolution. Understanding their early activity helps answer how they formed. Some may have resulted from direct gas cloud collapse.

The team plans further studies to explain the difference. They will search more galaxies from early cosmic periods. Their goal is to better understand the universe’s infancy.

Their research was published in The Astrophysical Journal.