Black holes could explain the universe’s origins
Nearby galaxies and their black holes could hold the answers to the existential questions that remain unanswered about the beginning of the universe. A black hole within a nearby galaxy called Tol 0440-381 shines about a million times brighter than the Sun, researchers from the University of Iowa recently found. This object suggests that powerful black holes could have played a major role in cosmic evolution.
Hundreds of thousands of years after the Big Bang, the universe was transparent for some time and had no stars. These dark ages ended about 400,000 years after the Big Bang, when the first stars began to form and light flooded the young cosmos.
These earliest stars were behemoths, about 30 to 300 times as massive as our Sun and millions of times as bright. These powerful stellar furnaces burned for only a few million years before exploding as supernovae.
While their lives were short and extreme, these earliest stars had a tremendous impact on our modern universe. The high-energy explosions released tremendous energy into space – energy powerful enough to split hydrogen atoms into electrons and protons, establishing a new period in the universe’s history dubbed the Epoch of Reionisation, which arose with the universe’s first
stars and galaxies and lasted until about a billion years after the Big Bang.
The powerful light these stars emitted and their frequent transformations into black holes after going supernova likely played a huge role in shaping the future galaxies that would soon populate the universe. The details of exactly how this all happened are still unclear, however.
The James Webb Space Telescope arrived at its final home in January 2022, and scientists aim to use its next-generation instruments to help answer such questions about the universe’s adolescence. In the meantime, the researchers are working on this question by studying nearby galaxies with instruments already in full working order. Using data collected by NASA’S Chandra X-ray Observatory in February 2021, the team identified the powerful black hole within
Tol 0440-381 and found similarities to the early stars that powered the Epoch of Reionisation.
“The implication is that outflows from black holes may be important to enable escape of the ultraviolet radiation from galaxies that reionised the intergalactic medium,” said Philip Kaaret, professor and chair in the department of physics and astronomy at the University of Iowa. “We can’t yet see the sources that actually powered the universe’s reionisation because they are too far away.”