Solving the mystery of these cosmic giants would represent a significant step in scientists' ongoing effort to understand why things are the way they are.Įnergy release is one of many ways black holes divulge their secrets. Their formation and evolution are clearly connected to the development of galaxies, and to the even larger story of our entire Universe's history and structure. Supermassive black holes interest scientists for more than just their energy efficiency. If you think of anything we burn with carbon, or chemical energy, or even what happens in stars, it's just a small, small fraction of what a black hole produces." "They transform mass into energy with up to 40% efficiency. "Black holes are the most effective, efficient engines in the Universe," says Marta Volonteri, a black hole researcher at l'Institut d'Astrophysique de Paris. Reaching temperatures higher than 10 million C, the accretion disc in a quasar releases blindingly bright radiation across the electromagnetic spectrum. But, just outside the event horizon, a spinning black hole can whip nearby material into a spinning, superheated disc. Space and time fold in on themselves, and the physical laws that describe how most of our Universe works break down. Within this sphere, light, energy, and matter are inescapably trapped. While the heart of a black hole remains unknowable to external observers, supermassive black holes can shine more brightly than an entire galaxy of stars, and can even produce "burps" of ultraviolet radiation as they consume material around them.īlack holes have a spherical boundary known as an "event horizon". Some of these giants have been present at least since the Universe was a mere 670 million years old – at a time when some of the oldest known galaxies were forming. Far-distant quasars, some of the brightest objects in the night sky, are actually ancient supermassive black holes that have set the cores of dying galaxies on fire. That's too short a time to get it that big just with accretion."Įven more mystifying, supermassive black holes already existed when the Universe was still in its relative infancy. "After they've collapsed, you've then got about thirteen and a half billion years to grow your black hole to billions of times the mass of the Sun. "Let's assume the very first stars formed black holes around 200 million years after the Big Bang," Smethurst says. In fact, collapsed stars grow so slowly, they couldn't possibly become supermassive just by absorbing new material. They are surprisingly inefficient at accreting (physicists' jargon for "sucking up") surrounding material, even in a dense galactic core. In reality, however, black holes don't live up to their monstrous reputation. Mystery solved, one might think – supermassive black holes are simply the hungriest and oldest of their kind. They barrel through the Universe sucking up everything in their path, growing larger and more voracious as they do. In popular culture, black holes are perfectly dark and endlessly hungry. The idea of black holes has been around for a century and is predicted in Albert Einstein's Theory of General Relativity. A dying star runs out of fuel, explodes in a supernova, collapses in on itself, and becomes so dense that even light cannot escape its intense gravity. There's little secret about how conventional – if they can be called that – black holes form and grow. But new techniques that look for the effects supermassive black holes have on the interstellar objects around them, and even at the ripples they create in the fabric of space and time, are providing new clues. Studying something that, by its nature is so dense that even light cannot escape from its centre, makes learning about it difficult. "The prettiest galaxies are the ones that could help us solve the mystery of how these black holes grow." "The ideal galaxies for my study are the most beautiful, perfect spirals you could possibly think of," says Becky Smethurst, a junior research fellow at the University of Oxford who studies supermassive black holes. This is where galaxy UCG 11700 could prove useful. Scientists believe almost every large galaxy has a supermassive black hole at its heart. While standard black holes start at around four times the mass of our Sun, their enormous relatives are millions, and sometimes billions, of times as massive. At the heart of this beautiful cosmic Catherine wheel is one of the most mysterious objects in the Universe – a supermassive black hole. For billions of years, the flocculent spiral arms of galaxy UCG 11700 have wheeled in peace, undisturbed by the collisions and mergers that have deformed so many other galaxies.īut while a spiral galaxy like UCG 11700 is pleasing to look at, something monstrous lurks in its midst. Halfway between the belly of Delphinus the Dolphin and the hind hoof of Pegasus the flying horse, a pristine pinwheel tumbles through space.
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