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Black Holes

The Network aims, as one of its projects, to simulate the collision of two Black Holes. Black Hole collisions are considered one of the of the most promising sources of gravitational waves. A black hole sitting quietly alone in space would emit no waves.

But what if two black holes collide? Imagine two rapidly spinning objects, many times more massive than the Sun, but the size of a small village, crashing into each other at nearly the speed of light! This violent event should emit a great burst of gravitational waves! Even so, the signals would be so weak when they arrive here on earth that they will be exceedingly difficult to detect, even with the new generation of gravitational wave detectors being built around the world. Such weak signals may be very difficult to see in the noise of the detector data.

However, if one knows what to look for in the data, it will be much easier to find the signals. Furthermore, once a signal is discovered, it is very important to interpret its meaning. However, at present there is no detailed understanding of the process of black hole colisions, nor of the specific form of the gravitational waves emitted. Our project aims to use large scale computers to simulate black hole collisions, in an attempt to provide information needed to find the signals that should be seen in gravitational wave detectors, and to interpret these signals if they are seen.

This sequence of images shows one of the first 3D simulations, carried out by members of the Network, of two spinning black holes merging in the final stages of a rapidly decaying orbit. The leftmost images shows the two individual black holes about to merge. The individual horizons are shown in the center of image (the larger black hole is just above a smaller one). The developing burst of radiation is shown shooting out towards the upper left direction and to the lower right. (Note that in computer simulation visualizations, black holes do not have to be black! Here we made them multicolored to bring out details of the curvature of their horizon surfaces!) The final image on the right shows the final black hole, with the two original black hole horizon surfaces still seen inside, and also shows the developing and intensifying burst of gravitational waves.

The Network is making good progress on this difficult problem, and from time to time we will update the website to provide more recent results.

Check out the Movies page for the latest black hole merger simulations!




This work has been supported by the EU Programme 'Improving the Human Research Potential and the Socio-Economic Knowledge Base' (Research Training Network Contract HPRN-CT-2000-00137).