SEPTEMBER 24, 2004
Fornax Cluster in Motion
EXPLANATION
Reminiscent of popular images of the lovely Pleiades star cluster that lies within our own Milky Way Galaxy, this false-color x-ray view actually explores the center of a much more extended cosmic family—the Fornax cluster of galaxies some 65 million light-years away. Spanning nearly 900,000 light-years, the Chandra Observatory composite image reveals high-energy emission from several giant galaxies near the Fornax cluster center and an immense, diffuse cloud of x-ray emitting hot gas. On the whole, the hot cluster gas seems to be trailing toward the upper left in this view. As a result, astronomers surmise that the Fornax cluster core is moving toward the lower right, encountering an intergalactic headwind as it sweeps through a larger, less dense cloud of material. In fact, along with another visible galaxy grouping at the outskirts of the cluster, the Fornax cluster core galaxies seem to be moving toward a common point, attracted by the dominating gravity of unseen structures of dark matter in the region.
Credit
C. A. Scharf, D. R. Zurek, M. Bureau (Columbia Univ.), CXC, NASA
