Inflating fat bubbles in clusters of galaxies by wide jets

We conduct two-dimensional (2D) hydrodynamical simulations of jets expanding in the intracluster medium (ICM). We find that for a fat, i.e., more or less spherical, bubble attached to the center to be formed, the jet should have high momentum flux and a large opening angle. Typically, the half-opening angle should be alpha greater than or similar to 50 degrees, and the large momentum flux requires a jet speed of v(j) similar to 10(4) km s(-1). The inflation process involves vortices and local instabilities, which mix some ICM with the hot bubble. These results predict that most of the gas inside the bubble has a temperature of 3 x 10(8) K less than or similar to T-b less than or similar to 3 x 10(9) K, and that large quantities of the cooling gas in cooling flow clusters are expelled back to the intracluster medium, and heated up. The magnetic fields and relativistic electrons that produce the synchrotron radio emission might be formed in the shock wave of the jet.