About millions of years ago, a cataclysmic energy flare ripped through our galaxy, the Milky Way. A team of astronomers said that the so-called Seyfert flare started near the supermassive black hole in the center of the galaxy. The impact of this was so strong that it was felt from 200,000 light-years away.
The discovery that the Milky Way's core was more compelling than previously speculated can lead to an entirely new reinterpretation of its evolution. Magda Guglielmo from the University of Sydney says that these results completely alter our understanding of our galaxy. We always thought about the Milky Way as an inactive galaxy with a not-so-bright center. The flare produced two ionization cones that sliced through the Milky Way. It bursted out into deep space and impacted the trail of gas, partially circling the galaxy known as the Magellanic Stream.
Led by Professor Bland-Hawthorne, his team used the information retrieved by the Hubble space telescope to calculate when the enormous explosions of high-energy radiation took place. And while astronomers have already suspected that these events did take place, new research dates this blast 3.5 million years ago—which is about 63 million years after the dinosaur era.
In astronomical terms, 3.5 million years is extraordinarily recent. At that point in time on Earth, asteroids have already caused the extinction of dinosaurs 63 million years in the past, and humanity's ancient ancestors, the Australopithecines, were already in Africa.
According to Professor Lisa Kewley, director of ASTRO 3-D, this is indeed a powerful dramatic event that occurred a few million years ago in the Milky Way's history.
She said that a humongous blast of energy and radiation came shooting out of the galactic center and into the surrounding material. "This shows that the center of the Milky Way is a much more dynamic place than we had previously thought. It is lucky we're not residing there!"
Astronomers discovered an unusual glow gleaming from the Magellanic Stream in 1966. Sagittarius A became the primary suspect when scientists began looking for the cause behind it.
The team first reported evidence of this explosion in 2013, when they identified the black hole as the cause. Their most recent work, published in the Astrophysical Journal, emphasizes and builds on their previous findings. They also estimate that the blast happened for a period of 300 years, which is not very long in galactic terms.
The researchers also added that with the question of how black holes evolve, influence, and interact with galaxies "is an outstanding problem in astrophysics." Black holes are areas where the matter is compressed by gravity to a point where the regular laws of physics breakdown. This eventually bends and distorts space and time.
By definition, they are not visible in the conventional sense, which makes them more difficult to study. Their existence is inferred from radiation expended as gas and debris swirl around them.
Also, in distinction to its "sleepy" personality, researchers detected last month that Sagittarius A was "growing hungrier," consuming more and more interstellar gas and dust than it had ever been seen doing before.
