|Hungry for More||
When a star or another stellar object brilliantly explodes in space, it usually signals the destruction of something. In the case of a blast spotted by NASA's Chandra X-ray Observatory, astronomers have recorded the most powerful explosion ever seen and they are amazed by what it's created.
The blast is taking place inside a galaxy cluster called MS 0735.6+7421. The eruption appears to have lasted more than 100 million years and produced the energy equivalent of hundreds of millions of gamma-ray bursts. Chandra scientists believe the explosion is the product of enormous amounts of matter being gobbled up by an apparently famished black hole.
Image to right: This image shows the Chandra X-ray image of the galaxy cluster MS 0735.6+7421. The two giant cavities visible are caused by twin jets of matter exploding through the hot gas. A supermassive black hole at the center of the bright X-ray emission caused the eruption.
The new Chandra images show a cloud of gas with two eroding cavities. Invisible to the naked eye, the cavities are believed to be caused by twin jets of matter momentarily expelled by the black hole. Chandra's unique ability to observe hot gas clusters allowed it to make this discovery that other telescopes missed.
A typical black hole usually forms after a dense neutron star collapses. When a star withers and burns out, a compact core of neutrons is left behind. As the particles are compressed together, they normally exert sufficient outward resistant pressure to sustain the size of the core. However, if enough neutrons are present, their combined gravitational attraction will overwhelm this pressure and cause the core to collapse and condense. The result is a relatively tiny object with such strong gravitational pull that not even light can escape it. A black hole has been created.
Once formed, a black hole will begin ingesting the gas, stars and other galactic material surrounding it. What's surprising scientists is just how much matter this black hole is consuming. "I was stunned to find that a mass of about 300 million suns was swallowed," said Brian McNamara of Ohio University in Athens.
Image to left: An artist's depiction shows how jets of matter shooting out from a black hole can erode the surrounding gas cloud. Jets such as these travel at supersonic speeds and can create cavities millions of light years across.
As a black hole devours more matter, it grows larger. However, when a black hole swells in size, its appetite generally decreases. The evidence provided by Chandra shows the hole is as hungry as ever. "This black hole is feasting when it should be fasting," said Paul Nulsen of the Harvard-Smithsonian Center of Astrophysics.
The mechanics of mammoth supermassive black holes like the one in MS 0735.6+7421 are unknown. How this peculiar black hole formed and why it continues to eat so ferociously are very big questions for astronomers. Scientists also wonder if the hole will keep the surrounding gas from cooling or generate large magnetic fields in the area. These are compelling questions that should certainly give experts using the Chandra X-Ray Observatory something hearty to chew on and whet their appetites for more.
+ Learn more about black holes
+ Chandra X-ray Observatory
Chandra X-ray Observatory Center and NASA's John F. Kennedy Space Center