Scientists Detect Quasar Variability 850 Million Years After Big Bang, Revealing Thin Accretion Disk
Updated
Updated · Nature.com · Jun 8
Scientists Detect Quasar Variability 850 Million Years After Big Bang, Revealing Thin Accretion Disk
3 articles · Updated · Nature.com · Jun 8
Summary
Multiwavelength observations found infrared and X-ray brightness changes in quasar J0439+1634, making it one of the earliest quasars with detected variability and opening a direct probe of black-hole feeding at cosmic dawn.
Five infrared filters traced rest-frame ultraviolet and optical emission from the accretion disk, while X-ray variability traced the corona, letting researchers separate structures around the supermassive black hole.
The variable spectrum indicates a geometrically thin, optically thick accretion disk, providing rare observational constraints on quasar structure just 850 million years after the Big Bang, when growth rates were high and environments extreme.
Data spanning 2000 to 2025 suggest the method can be scaled up with Rubin Observatory and the Roman Space Telescope, which are expected to find large samples of variable high-redshift quasars for population studies of early black-hole growth.
As the Roman telescope prepares for its 2026 launch, can it finally solve how monster black holes grew so big, so fast?
Why were the universe's first monster black holes so unexpectedly calm, challenging theories about their chaotic growth?
Landmark Detection: Flickering Quasar J0439+1634 Challenges Black Hole Growth Models in the Early Universe
Overview
In June 2026, scientists made a landmark discovery by observing the earliest known flickering quasar, J0439+1634, just 850 million years after the Big Bang. Using NASA’s NEOWISE mission, they detected a 20% fluctuation in its brightness, revealing that even at this early time, supermassive black holes were rapidly and chaotically feeding. This flickering provides crucial clues about the structure and behavior of the black hole’s accretion disk, offering new insights into how these massive objects grew so quickly in the early universe. The discovery challenges previous models and reshapes our understanding of cosmic evolution.