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Magnetic Jets and Lobes in Cosmological MHD

Magnetic Jets and Lobes in Cosmological MHD. Hui Li Los Alamos National Laboratory NSF/DOE Center for Magnetic Self-Organization (CMSO) Collaborators: H. Xu, D. Collins, S. Li, M. Morman. Overview of Observations and Magnetic Jet Model Results on 3D MHD Jet/Cluster Simulations

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Magnetic Jets and Lobes in Cosmological MHD

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  1. Magnetic Jets and Lobes in Cosmological MHD Hui Li Los Alamos National Laboratory NSF/DOE Center for Magnetic Self-Organization (CMSO) Collaborators: H. Xu, D. Collins, S. Li, M. Morman • Overview of Observations and Magnetic Jet Model • Results on 3D MHD Jet/Cluster Simulations • Results on Cosmological MHD Jet/Cluster Simulations

  2. Papers and Posters 1) Basic model: Li et al. ApJ, 2006 2) Jets in Static Clusters: Nakamura, Li, Li, ApJ, 2006, 2007 3) Comparison w. X-ray Bubbles: Diehl et al. ApJ, 2008 4) Comparison w. Herc A Observ: Nakamura et al. ApJ, 2008 5) Cosmological MHD Jet+Cluster Simulation: Xu et al. ApJL, 2008 6) Long-time evolution of magnetic bubble: Liu et al. ApJL, submitted Both Steven Diehl and Hao Xu have posters at this meeting. We are also looking for a postdoc in this area.

  3. Jets and Lobes in Galaxy Clusters : Effects of ICM Dynamics ? Perseus (Fabian et al.) Hydra A (Wise et al.) MS0735.6+7421 (McNamara et al.) ~ 250 kpc ~ 400 kpc ~ 1 Mpc

  4. Leahy et al. (1996)

  5. Astrophysical Jets: Engine and Injection • Poloidal flux:  ~ 104 (1014)2 ~ 1032 (G cm2) • Toroidal flux: ~ (t)G cm2) • Current: I ~ B R ~ 1018 A • Mag. energy injection rate: dEmag/dt = Iz V - Ploss • Expansion: Iz(r,t), (r,t), and Ploss(r,t).  Ipol BH disk r0 Li et al. (2006)

  6. Li et al. 2006; Nakamura, Li, Li 2006; 2007

  7. With Both Magnetic and Kinetic Injections Ipol r0 Li (2008)

  8. 3D MHD Simulations Cluster: isothermal, hydrostatic (initially) T = 4 keV, nc = 0.01 (1/cm3), Rc = 40 kpc;  = 0.5 Jets in Static Clusters: injection time: 40 Myr injection magnetic energy: ~ 3x1060 ergs (~2.5x1045 ergs/s) mass injection rate: < Msun / yr

  9. Magnetic field and current distribution(as kinetic energy injection increases…) Run B Run C Run A EB = 2.6x1060 ergs Ek < 2.6x1056 ergs EB = 1.8x1060 ergs Ek = 0.7x1060 ergs EB = 1.6x1060 ergs Ek = 2.3x1061 ergs

  10. Run F Run E Effects of Flows: Stabilization

  11. Azimuthally averaged velocity profile at z=3 • Sub-Alfvenic • with shear • Supersonic AlfvenSpeed (run F) Alfven speed (run E) Velocity Flow Speed (run F) Flow Speed (run E) Radius

  12. Comparison of Energy Evolution Run E: without Ek injection Run F: with Ek injection Einj=EBinj+EKinj Einj = EBinj EB EB Eth Eg Eth Eg EK EK

  13. Run F: Jets/Lobes are mostly magnetically dominated Magnetic/Thermal log10 (eB/eth) Magnetic/Kinetic log10 (eB/ek)

  14. Estimating Magnetic Fields and Energy Density Rlobe Measuring B: could be small in the main volume. But magnetic energy contained in the central region is a sizable fraction of the total lobe.

  15. Analysis of 64 Bubbles in 32 Clusters See Poster by Diehl (Diehl et al. 2008) magnetic Hydro Adiabatic expansion

  16. Cosmology Ideal-MHD Code Xu et al. (2008, method paper)

  17. Cosmological AMR+MHD Simulation(see H. Xu’s poster) • Developed AMR+MHD and implemented in ENZO code. • ENZO AMR+Hydro simulation: h=0.7, m=0.3, b=0.026, =0.7, 8=0.928 • Volume: 256 Mpc/h • Initial 1283 root grid from z=30, followed with 8 level refinements (~8kpc/h) for magnetic fields.

  18. Cluster formation with an AGN feedback (Xu et al. 2008) X-ray Intensity

  19. Magnetic Energy Evolution

  20. Lobes are magnetically dominated

  21. Heating the Cluster Core Region(see Hao Xu’s poster) T=156 Myr T=36 Myr T=336 Myr T=670 Myr Change of inflow mass of clusters with and without AGN injection

  22. Magnetic jet input at high redshift Magnetically dominated jet input at a halo at z=3 size: 80 Mpc comoving Injection B fields strength: 40 microgauss Halo properties: Rvir = 0.248462 (Mpc)‏ Mvir = 3.04303e+13 (M_solar)‏ Mvir (gas) = 1.51376e+12 (M_solar)‏ Mvir (dm) = 2.89165e+13 (M_solar)‏

  23. T=108Myr T=228Myr

  24. T=348Myr T=528Mry

  25. T=648Myr T=768Myr

  26. T=1.02Gyr T=1.38Gyr

  27. T=2.10Gyr T=2.82Gyr

  28. Jets/lobes as magnetically dominated system with large current • “Flaring”/Lobe formation related to background ICM pressure profile (coupled with 3D MHD instability) • Lobe size determined by balance between external pressure and total current • Magnetic energy is gradually converted to thermal and kinetic energies of the jet/lobes • Morphology of jet/lobe is heavily influenced by background ICM dynamics, though magnetic fields crucial in maintaining the integrity of jets/lobes • Relic evolution, leading to magnetization of ICM/IGM Summary

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