A Mysterious Black Hole
When I covered black holes a while back, I said I would talk about a specific one separately, and that’s what we will do in this article. The black hole in question is supermassive and the farthest from us we’ve discovered so far, sitting in a quasar galaxy 13 billion lightyears away. To explain what a quasar is, let’s experience the birth of a supermassive black hole.
Quasars
We are in the early universe. Gas clouds are scattered everywhere and millions of stars are born from the thicker ones. Most of the stars are supermassive, which means that they burn hot and fast, explode, and then create black holes. Gravity pulls a lot of them together to form larger ones and over hundreds of millions of years, each one grows, producing stronger gravity and pulling in more gas. They have now earned the title of supermassive. Gas actually heats up as it advances to them. Then, inevitability, the black hole overloads and the gas is ejected as it starts to ignite. Consequentially, gas is blasted through the galaxy in huge energy jets, each 20 times our solar system and at a rate of 10 Earths per minute. When this gas does run out, the jets shrink and die. These jets are what we call a quasar.
Unsurprisingly, quasars are the brightest objects in the universe. They are, as we’ve seen, the opposite of black holes. Black holes acquire gas and quasars blow it out. Interestingly, every large galaxy, including our own, was likely a quasar in its youth. Scientists have found thousands of them, but finding the ones farthest away has been lengthy for Bram Venemans and his team. They estimate that there are 20 to 100 as bright and as distant as the one that hosts the black hole we focussing on, across the sky.
To find our quasar, Bañados (part of Venemans’ team) spotted a few candidates he thought could be distant, then analysed them with the Magellan Telescopes in Chile.
The Black Hole
Due to light having to travel, telescopes reveal the black hole as it was 690 million years after the Big Bang. It started to form when the universe was transitioning from a murky to starlit one. Its mass is 800 million times greater than our Sun, which is the “abnormality”. Robert Simcoe (co-author of the study) says, “The universe was just not old enough to make a black hole that big.”
Bañados and Daniel Stern (another co-author) said that this is a challenge for theories of the growth of supermassive black holes. It’s thought that they grow by acquiring mass from their surroundings. Enormous ones like this should take much longer than 690 million years to form. Simcoe explains that “If you start with a seed like a big star, and let it grow at the maximum possible rate, and start at the moment of the Big Bang, you could never make something with 800 million solar masses.”
The Debate
Astronomers surmise that there must have been special conditions to allow rapid growth in the early universe, but the reason remains unknown. Simcoe claims that “…there must be another way that it formed. And how exactly that happens, nobody knows.” So was there an unknown mechanism at work, and do similar events still happen out there?
Conclusions
This discovery raises many questions regarding the true nature of space and whether or not there is some kind of creator or other force at work. Simcoe states that “This is the only object we have observed from this era”, which makes the discovery rare at present and means that it will uncover information about the universe when it was 5% its current age. Also, black holes are key to understanding how galaxies form and evolve with time. So it’ll be interesting to see how this galaxy evolves in the distant future, considering the nature of its supermassive black hole.