1. Inflating Fat Bubbles in Clusters of Galaxies by Slow Wide Jets Assaf Sternberg (did the work) Noam Soker (speaker today) Technion, Israel July 2008

2. Goal: To form ‘Fat’ Bubbles PERSEUS IN VISIBLE AND X-RAY

3. Old bubble Young bubbles Rayleigh-Taylor instability From Fabian and collaborators

4. Cluster Planetary nebula More ‘Fat’ Bubbles

5. From planetary nebulae we learn that there is no need for relativistic effects or strong magnetic fields NGC 3587 Guerrero et al. From Gorny et al. NGC 2818 He 2-116. NGC 3195 He 2-37.

6. Initial Setting Low Density High Density ICM in hydrostatic equilibrium Wide Jet or Precessing Jet

7. RESULTS: (1) Fat Bubbles ( Assaf Sternberg PhD thesis) The jet: Temperature Density After 2.5 Myr After 5 Myr Forward shock (ICM is shocked) Reverse shock (jet is shocked) Contact discontinuity

8. RESULTS: (2a) Buoyant Bubbles Evolution with gravity included. Here the density and velocity maps when the jet is shut off after 10Myr activity. Note 2: Vortex Note 1: ICM Backflow Note 3: a dense shell with momentum During the inflation phase the bubble is stable (Pizzolato & Soker 2006)

9. Evolution of a bubble inserted by hand After 15 Myr After 30 Myr Jet-inflated bubble Artificial Bubble Full evolution of a jet-inflated bubble After 15 Myr Instabilities Momentum of shell leads to faster motion A weak shock Note 4: mixing of hot gas with the ICM Note 5: no instabilities RESULTS (2b) Evolution (Sternberg & Soker, MNRAS Letter, in press)

10. Ripples in Perseus (Fabian et al.)

11. RESULTS: (3) Sound Waves: Wide jets Density Jets were active from to A weak shock Note 7: Several sound waves Note 6 : Complicated and changing bubbles’ shape

12. Density Jet was active at all times, starting at t=0. Note 7: Several sound waves RESULTS: (3) Sound Waves: Precessing jets A weak shock: Mach=1.3

13. SUMMARY Slow massive jets can account for: (1)Recycling of gas that cools from the ICM. (2) Formation of fat bubbles close to the center. (3) Allowing the bubble to rise to large distances. (4) Efficient energy transfer form bubbles to the ICM. A realistic jet-inflation process shows that: 1) Vortices can stabilize the bubble. 2) The expanding shell around the bubble stabilizes it. 3) An efficient mixing between bubbles and the ICM. 4) One inflation episode excites several sound waves.