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Free-Wheeling Galaxies Collide in a Blaze of Star Birth

A dusty spiral galaxy appears to be rotating on edge, like a pinwheel, as it slides through the larger, bright galaxy NGC 1275 in this NASA Hubble Space Telescope image. These galaxies are believed to be colliding at over 6 million miles per hour. Even so, it will take as much as 100 million years to complete the pass.

NGC 1275 is about 235 million light-years away in the constellation Perseus. Embedded in the center of a large cluster of galaxies known as the Perseus Cluster, it is also known to emit a powerful signal at both X-ray and radio frequencies. The galaxy collision causes the gas and dust already existing in the central bright galaxy to swirl into the center of the object. The X-ray and radio emission indicates the probable existence of a black hole at the bright galaxy's center.

The red filaments are composed of cool gas being suspended by a magnetic field, and are surrounded by the 100-million-degree Fahrenheit hot gas in the center of the Perseus galaxy cluster. The filaments are dramatic markers of the feedback process through which energy is transferred from the central black hole to the surrounding gas. The filaments originate when cool gas is transported from the center of the galaxy by radio bubbles that rise in the hot interstellar gas.

Energetic activity of gas swirling near the black hole blows bubbles of material into the surrounding galaxy cluster. Long gaseous filaments stretch out beyond the galaxy, into the X-ray–emitting gas that fills the cluster.

These filaments are the only visible-light manifestation of the intricate relationship between the central black hole and the surrounding cluster gas. They provide important clues about how giant black holes affect their surrounding environment.

Astronomers have resolved individual threads of gas which make up the filaments. The amount of gas contained in a typical thread is around one million times the mass of our own Sun. They are only 200 light-years wide, are often very straight, and extend for up to 20,000 light-years. The filaments are formed when cold gas from the core of the galaxy is dragged out in the wake of the rising bubbles blown by the black hole.

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