Narrator (Megan Watzke, CXC): This image contains one of the most complex galaxy clusters known, which is located about 5.4 billion light years from Earth. In this system known as MacsJ0717 for short, 4 separate galaxy clusters have collided. This is the first time such a complex crash of galaxy clusters has been documented. In this composite image, data from the Chandra X-ray Observatory reveal the cluster's hot gas, while an optical image from the Hubble Space Telescope shows the individual galaxies in the system. The gas in this image is color-coded to show temperature, just like a weather map for Earth. In this case however, the temperatures range from millions to tens of millions of degrees, where the coolest gas here is colored red, the hottest gas is blue, and the temperatures in between are purple.
Revised: May 15, 2009