Imagine the entire universe suddenly blazing with light in a flash that lasted just a brief moment in time and then vanishing, leaving behind the most massive black holes ever discovered. This dramatic scenario forms the heart of a new theory that could solve one of astronomy’s biggest mysteries about supermassive black holes and how they got so enormous so quickly after the Big Bang.
The mystery began when the James Webb Space Telescope started discovering supermassive black holes in the most distant corners of space, existing when the universe was barely a billion years old. These objects are typically millions or billions of times more massive than our Sun, yet somehow they grew to such enormous sizes in what amounts to a very short cosmic timescale. Traditional theories struggled to explain how black holes could bulk up so rapidly in the early universe’s sparse environment.
This is the first image of Sgr A, the supermassive black hole at the centre of our galaxy. It’s the first direct visual evidence of the presence of this black hole. It was captured by the Event Horizon Telescope (Credit : EHT Collaboration)*
University of Virginia astrophysicist Jonathan Tan has proposed a new framework called “Pop III.1” that explains not only how these giants formed, but also how they may have fundamentally shaped the early universe. The theory suggests that the very first generation of stars were unlike anything we see today, supermassive stellar beasts that grew to incredible sizes and then died in spectacular fashion, leaving behind the black hole seeds that would eventually anchor entire galaxies.
Tan’s Pop III.1 theory suggests a radical new idea that the very first stars in the universe were themselves supermassive, growing to extraordinary sizes under the influence of dark matter annihilation, a process that pumped enormous amounts of energy into these stellar giants. These Population III.1 stars were fundamentally different from any stars we observe today, existing in a universe filled with pristine hydrogen and helium, completely free of the heavier elements that characterise modern star formation.
But here’s where the theory gets truly spectacular. According to Tan’s model, these supermassive stars didn’t just quietly form and die, quite the contrary, they announced their existence with brilliant flashes of light that rapidly ionised hydrogen gas throughout the entire universe.
“Our model requires that the supermassive star progenitors of the black holes rapidly ionised the hydrogen gas in the universe, announcing their birth with bright flashes that filled all of space,” – Jonathan Tan from the University of Virginia
This “flash ionisation” represents a previously unknown chapter in the history of the universe, occurring much earlier than the ionisation we already know about from normal galaxies. The implications extend far beyond black hole formation. This early ionisation event might help resolve several puzzling tensions in modern cosmology, including the so-called “Hubble Tension”, a disagreement between different methods of measuring the universe’s expansion rate that has been frustrating astronomers for years.
If confirmed, this theory would fundamentally reshape our understanding of the earliest phase of the evolution of the universe. Rather than a gradual brightening as the first normal stars slowly formed, the universe may have experienced a spectacular fireworks show as supermassive stars blazed to life across all of space, only to quickly burn out and leave behind the massive black holes that would become the gravitational anchors for every large galaxy we see today, including our own Milky Way.
Source : ‘Pop III.1’ model explains origins of black holes and early cosmic ionization