By Brandon Moseley
Alabama Political Reporter
At the center of our Milky Way galaxy is a super massive black hole. On Monday, January 5 NASA astronomers announced at an American Astronomical Society conference that they have detected the largest X-ray flare ever from the supermassive black hole at the center of the Milky Way using NASA’s Chandra X-ray Observatory. NASA says that this event was 400 times brighter than the usual X-ray output from the black hole. NASA astronomers have observed the largest X-ray flare ever detected from the supermassive black hole at the center of the Milky Way galaxy.
Astronomers say that this event, detected by NASA’s Chandra X-ray Observatory, raises questions about the behavior of this giant black hole and its surrounding environment. Astronomers have named the supermassive black hole at the center of our galaxy Sagittarius A* (Sgr A*). Astronomers estimate that Sgr A* has a mass 4.5 million times bigger that the mass of our sun.
The Astronomers were using Chandra to observe how Sgr A* would react to a nearby cloud of gas known as G2.
Astronomer Daryl Haggard with Amherst College in Massachusetts said, “Unfortunately, the G2 gas cloud didn’t produce the fireworks we were hoping for when it got close to Sgr A*. However, nature often surprises us and we saw something else that was really exciting.”
On Sept. 14, 2013, Haggard and her team detected the massive X-ray flare from Sgr A*, which was 400 times brighter than its usual, quiet state. This “megaflare” was nearly three times brighter than the previous brightest X-ray flare from Sgr A* in early 2012. After Sgr A* settled down, Chandra observed another enormous X-ray flare 200 times brighter than usual on Oct. 20, 2014.
Astronomers do not believe that the flare had anything to do with the G2 cloud they were observing due to its distance from the black hole at the time.
The astronomers speculate that the giant x-ray flare could be due to an asteroid becoming trapped by the massive black hole’s gravitational forces and then exploding. The explosion released the x-rays.
The papers co-author Fred Baganoff from MIT wrote, “If an asteroid was torn apart, it would go around the black hole for a couple of hours – like water circling an open drain – before falling in. That’s just how long we saw the brightest X-ray flare last, so that is an intriguing clue for us to consider.”
Astronomers have also suggested that the magnetic field lines within the gas flowing towards Sgr A* could be tightly packed and become tangled. These field lines may occasionally reconfigure themselves and produce a bright outburst of X-rays. These types of magnetic flares are seen on the sun, and the Sgr A* flares have similar patterns of intensity.
Study Co-author Gabriele Ponti said, “The bottom line is the jury is still out on what’s causing these giant flares from Sgr A*. Such rare and extreme events give us a unique chance to use a mere trickle of infalling matter to understand the physics of one of the most bizarre objects in our galaxy.” Gabriele Ponti is with the Max Planck Institute for Astrophysics in Garching, Germany.
The scientists are also studying a magnetar near Sgr A*. A magnetar is a neutron star with a strong magnetic field. This magnetar is undergoing a long X-ray outburst, and the Chandra data are allowing astronomers to better understand this unusual object.
These results were presented at the 225th meeting of the American Astronomical Society being held in Seattle.
NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.
