October 23, 2012
Astronomers Discover Galactic Afterburner Spewing From Supermassive Black Hole
[ Watch the Video: High Speed Video Of Shock Diamond ]
April Flowers for redOrbit.com - Your Universe Online
A supersonic jet of material that looks amazingly similar to the afterburner flow of a fighter jet is blasting over two million light-years from the center of a distant galaxy. The big difference, however, is that the jet engine responsible for this material is a supermassive black hole and the material is moving at nearly the speed of light.
A new study, published this past weekend in the Astrophysical Journal Letters, reveals the galaxy-scale jet to have bright and dark regions. This is similar to the phenomenon in an afterburner exhaust called "shock diamonds."
The jet has been studied previously, however a new image taken using the CSIRO Australia Telescope Compact Array (ATCA) radio telescope in New South Wales reveals regularly spaced areas that are brighter than the rest of the jet in a pattern echoing the way a jet's afterburner has brighter diamond-shaped areas in its general glow.
The ATCA is an array of 22-m antennas used for radio astronomy at the Paul Wild Observatory, operated by CSIRO's Astronomy and Space Science division.
“One intriguing possibility is that the pattern we see in this cosmic jet is produced in the same way as the pattern in the exhaust from fighter jet engines,” said Dr Leith Godfrey, from the Curtin University node of the International Centre for Radio Astronomy Research.
Jets are produced when material falls onto a supermassive black hole at the center of a galaxy, Godfrey said, but many details beyond that remain unknown.
“Massive jets like this one have been studied for decades, since the beginning of radio astronomy, but we still don´t understand exactly how they are produced or what they´re made of,” he said.
“If the brighter patches are caused by the same process in astronomical jets as they are in earthly jet engines, then the distance between them can give us important information about the power of the jet and the density of the surrounding space.”
The jets like the one Godfrey and his colleagues studied are the largest objects in the Universe, about 1000 times larger than the Milky Way.
“If we want to understand how galaxies form and grow, we need to understand these jets. They are extremely powerful and are believed to stop stars forming in their parent galaxy, limiting how big the galaxies can grow and effecting how the Universe looks today,” he said.
“This new image of the jet shows detail we´ve never seen before and the pattern we revealed provides a clue to how jets like this one work,” said Dr Jim Lovell, from the University of Tasmania.
“This particular jet emits a lot of X-rays, which is hard to explain with our current models. Our new find is a step forward in understanding how these giant objects emit so much X-Ray radiation, and indirectly, will help us understand how the jet came to be.”
Image 2 (below): The phenomenon known as ℠shock diamonds´ in the afterburner of a NASA SR-71B Jet. The similarity between a jet afterburner and the enormous high powered astronomical jet Dr Godfrey and colleagues studied is striking. Image Credit: NASA