1. Thermal / Non-thermal plasma Interactions in Clusters The Good, the Bad & the Puzzling L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100

2. The BIG Questions How can relativistic plasmas, seen through synchrotron radiation, reveal the dynamics and evolution of clusters? SYNCHROTRON, clues to  DYNAMICS ? How does the dynamics of the thermal plasma affect the growth of the magnetic field and the acceleration of relativistic particles? DYNAMICS causes  B field and CRs ? L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100

3. Key Messages L. Rudnick MN Inst. for Astrophysics Zeldovich 100 GOOD NEWS : хорошие новости AGN influences on thermal X-ray plasma are well documented (heating, cavities, etc) Shocks seen in radio, sometimes in X-ray & S-Z, are consistent with expectations from theory, connected to cluster mergers Radio halos likely result from expected turbulence in mergers BAD NEWS: плохие новости Mach numbers expected from simulations and measured in X- ray inconsistent with spectral index of radio emission. Missing shocks, either radio or X-ray PUZZLING NEWS: головоломки Mild mergers with no shocks also produce giant radio halos. 3D structure of giant shock in Abell 2256 is not simple to explain Radio galaxies sometimes seen at edge of shocks – why? Юрий Никулин Max Otto von Stierlitz Максим Максимович Исаев with support from U.S. NSF, AST112195

4. The GOOD News Radio galaxy  ICM interactions L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100 ACTIVE PASSIVE

5. The GOOD News Merger shocks: simulations and observed relics L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100 Vazza et al. 2012, MNRAS 421 1868

6. The GOOD News L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100 Keeping electrons energized: CRe lifetimes ~ 10 8 y CRe diffusion times ~ 10 10 y W. Couch M. Owers Merger-driven turbulence

7. The GOOD News Radio halos  mergers L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100 Cassano+ 2011 Halos DISTURBED RELAXED

8. The GOOD News L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100 A. Simionescu et al. 2013 ApJ 775 4 Planck intermediate results. X. Physics of the hot gas in the Coma cluster, 2013 Consistent shock story - Radio, X-ray, S-Z Brown & Rudnick, 2011 RADIO X-RAY S-Z

9. Mismatched Mach numbers ? M < 2 3.3 < M < 4.6 X-ray shock radio spectrum The BAD News Ogrean+2013 X-ray shock radio spectrum van Weeren+ 12  inj= -0.6 to -0.7

10. Do shocks look too efficient? Tension with  -ray limits? The BAD News

11. X-ray shock Radio shock Where’s the radio shock? Why the offset?

12. The PUZZLING News головоломки L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100 PUZZLING Exploring low surface brightness radio emission Farnsworth+2013

13. Can MILD mergers  Giant Radio Halos? Farnsworth+ 2013 The PUZZLING News RADIO X-Ray Rossetti+ 2013 Abell 2142

14. Abell 2256 – where’s the shock? with F. Owen, NRAO & J. Eilek, NMIMT Radio X-ray The PUZZLING News

15. Abell 2256 – where’s the shock? with F. Owen, NRAO & J. Eilek, NMIMT The PUZZLING News Flat spectrum Steep spectrum

16. The PUZZLING News Radio Galaxy – relic/shock connection? Bonafede+14 van Weeren+ 2010 Pizzo+2010

17. Key Messages L. Rudnick MN Inst. for Astrophysics Zeldovich 100 GOOD NEWS : хорошие новости AGN influences on thermal X-ray plasma are well documented (heating, cavities, etc) Shocks seen in radio, sometimes in X-ray & S-Z, are consistent with expectations from theory, connected to cluster mergers Radio halos likely result from expected turbulence in mergers BAD NEWS: плохие новости Mach numbers expected from simulations and measured in X- ray inconsistent with spectral index of radio emission. Missing shocks, either radio or X-ray PUZZLING NEWS: головоломки Mild mergers with no shocks also produce giant radio halos. 3D structure of giant shock in Abell 2256 is not simple to explain Radio galaxies sometimes seen at edge of shocks – why? Юрий Никулин Max Otto von Stierlitz Максим Максимович Исаев with support from U.S. NSF, AST112195

18. radio.galaxyzoo.org