Two giant black holes reveal bizarre behavior
Huge black holes at the center of two separate galaxies surprise scientists with strange antics.
Fri, May 28 2010 at 1:58 PM
XXX: A striking example of the power and effervescence of super massive black holes is shown in this composite image of the elliptical galaxy M87 in the Virgo Cluster. (Photo: NASA/CXC/SAO/W)
A black hole is a deformation of space through which no light can escape. It is caused by an extremely dense mass at its center and can emit as much energy as a billion suns. Matter nearing a black hole will get sucked in by huge magnetic fields while approaching the speed of light. Scientists have been able to observe some consistent behaviors from black holes, usually centered on its mass, charge and angular momentum.
But recently, scientists noticed some bizarre behavior from two gigantic black holes at the center of two different galaxies. Space.com reports that one huge black hole in a neighboring galaxy has been mysteriously brightening in recent years. Another black hole seems to have moved from the center of its galaxy. These new discoveries will enable experts to understand more about the mysteries of these massive gravitational behemoths.
In the first study, scientists looked at a super massive black hole in the Andromeda galaxy. This black hole became 100 times brighter after an outburst on Jan. 6, 2006. Afterwards, the black hole dimmed but was still 10 times brighter than it was prior to the outburst. Experts feel this may indicate that a high amount of matter fell out of the hole, followed by smaller amounts. They feel the consequent brightening could exist because the black hole is capturing winds from an orbiting star or that a gas cloud has been sucked into the hole.
But why did it brighten in the first place? Experts are unsure. Zhiyuan Li is a team member on the study with the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass. As he told Space.com, "It's important to figure out what's going on here because the accretion of matter onto these black holes is one of the most fundamental processes governing the evolution of galaxies.” They believe that a sudden release of energy from the magnetic fields in the black hole may be the culprit.
In a separate study, scientists determined that the “iconic” M87 black hole, thought to be at the center of a nearby M87 giant galaxy, has been displaced from the center. Experts think this is because two smaller black holes combined to push it off center. Daniel Batcheldor of the Florida Institute of Technology is the lead researcher on this study. According to Batcheldor, "The theoretical prediction is that when two black holes merge, the newly combined black hole receives a kick due to the emission of gravitational waves, which can displace it from the center of the galaxy.”
M87 was one of the first galaxies to reveal that it had a black hole at its center — since then, astronomers have concluded that most galaxies have a central super massive black hole. These new findings also raise questions about the merger of galaxies for scientists.
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