In the heart of an active galaxy, matter falling toward a supermassive black hole generates jets of particles traveling near the speed of light. Image Credit: NASA’s Goddard Space Flight Center Scientific Visualization Studio
Researchers have recently discovered a group of five black holes believed to be some of the youngest and most powerful ever identified.
A group of Clemson University scientists have identified a black hole and four others similar to it that range from 1.4 billion and 1.9 billion years old that emit copious gamma rays—light of the highest energy—that are billions of times more energetic than light that is visible to the human eye.
Previously the earliest gamma-ray blazars—a type of galaxy whose intense emission is powered by extremely powerful relativistic jets launched by monstrous black holes—were more than 2 billion years old.
Marco Ajello, an astrophysicist at the Clemson University College of Science, explained the discovery.
“The discovery of these supermassive black holes, which launch jets that emit more energy in one second than our sun will produce in its entire lifetime, was the culmination of a yearlong research project,” Ajello said in a statement. “Our next step is to increase our understanding of the mechanisms involved in the formation, development and activities of these amazing objects, which are the most powerful accelerators in the universe.
“We can’t even come close to replicating such massive outputs of energy in our laboratories,” he added. “The complexities we’re attempting to unravel seem almost as mysterious as the black holes themselves.”
Ajello, working with Clemson post-doc Vaidehi Paliya and Ph.D. candidate Lea Marcotulli, worked closely with the Fermi-Large Area Telescope collaboration, an international team of scientists that includes Roopesh Ojha, an astronomer at NASA’s Goddard Space Flight Center and Dario Gasparrini, of the Italian Space Agency.
The team used refurbished software to significantly boost the orbiting telescope’s sensitivity to a level that made these latest discoveries possible.
“People are calling it the cheapest refurbishment in history,” Ajello said. “Normally, for the Hubble Space Telescope, NASA had to send someone up to space to physically make these kinds of improvements.
“But in this case, they were able to do it remotely from an Earth-bound location,” he added. “And of equal importance, the improvements were retroactive, which meant that the previous six years of data were also entirely reprocessed.”
The research team cataloged 1.4 million quasars—galaxies that harbor at their centers active supermassive black holes.
Over the course of a year, they narrowed their search to 1,100 objects, of which five were determined to be newly discovered gamma-ray blazars that were the farthest away and youngest ever identified.
“After using our filters and other devices, we were left with about 1,100 sources,” Paliya said in a statement. “And then we did the diagnostics for all of these and were able to narrow them down to 25 to 30 sources.
“But we still had to confirm that what we had detected was scientifically authentic,” he added. “So we performed a number of other simulations and were able to derive properties such as black hole mass and jet power.
“Ultimately, we confirmed that these five sources were guaranteed to be gamma-ray blazars, with the farthest one being about 1.4 billion years old from the beginning of time.”
They are also some of the largest types of black holes ever observed, on the order of hundreds of thousands to billions of times the mass of the Sun.
All galaxies have black holes at their centers with some actively feeding on the matter surrounding them and others lying relatively dormant.
According to Ajello, one out of every 10 black holes in today’s universe is active, but during the earlier days of the universe about half of black holes were considered active.
Ajello said one of the most surprising parts of the discovery was how much the black hole grew in just 1.4 billion years.
“How did these incomprehensibly enormous and energy-laden black holes form so quickly?” Ajello said. “Is it because one black hole ate a lot all the time for a very long time? Or maybe because it bumped into other black holes and merged into one?
“To be honest, we have no observations supporting either argument,” he added. “When we do eventually solve them, we will learn amazing things about how the universe was born, how it grew into what it has become, and what the distant future might hold as the universe continues to progress toward old age.”
