Powerful eruption in galaxy cluster MS 0735, composite radio and Chandra X-ray image. Two cavities (blue) have been formed in the hot gas (red) around the galaxy cluster. These cavities contain a magnetised bubble of high-energy electrons. They are a result of a massive eruption from the central black hole, which was probably caused when huge amounts of gas swirled towards it. A fraction of this gas was emitted as high energy particles, pushing aside the hot gas cloud to produce the cavities. The mass of displaced gas is greater than that of the entire Milky Way galaxy.