BLACK holes blowing huge bubbles may explain the lack of star formation in the cores of galaxy clusters.
Gas at the centre of galaxy clusters should be cooling as it loses energy; this would allow nearby material to compress the gas and create ideal conditions for making stars. But giant 鈥渂ubbles鈥� of hot, low-density gas may be dragging away the cool gas, say Edward Pope of the University of Victoria in British Columbia, Canada, and colleagues. These form when a black hole belches out jets of hot plasma, which are then pushed out of the core by surrounding denser gas.
Pope and his colleagues studied filaments of material 鈥� some up to 30,000 light years long 鈥� trailing in the wake of such bubbles in the Perseus cluster. They calculated that the filaments have their shape because they are made of dragged cold gas. By removing so much gas from near the core, the bubbles make star formation there less likely, the team say. Their paper will appear in .
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The research is a new take on an old problem, says Brian McNamara of the University of Waterloo in Ontario, Canada. 鈥淭hey have their own angle on it, which is pretty interesting.鈥�
