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Cosmological MHD Hui Li Collaborators: S. Li, M. Nakamura, S. Diehl, B. Oshea, P. Kronberg, S. Colgate (LANL) H. Xu, M. Norman (UCSD), R. Cen (Princeton) Observational overview of large scale magnetic fields Several examples of numerical modeling of cosmological MHD

Cosmological MHD

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Cosmological MHD. Hui Li Collaborators: S. Li, M. Nakamura, S. Diehl, B. Oshea, P. Kronberg, S. Colgate (LANL) H. Xu, M. Norman (UCSD), R. Cen (Princeton). Observational overview of large scale magnetic fields Several examples of numerical modeling of cosmological MHD. - PowerPoint PPT Presentation

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Page 1: Cosmological MHD

Cosmological MHDHui Li

Collaborators:

S. Li, M. Nakamura, S. Diehl, B. Oshea,

P. Kronberg, S. Colgate (LANL)

H. Xu, M. Norman (UCSD), R. Cen (Princeton)

Observational overview of large scale magnetic fields Several examples of numerical modeling of cosmological MHD

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Part I:

Observations

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Hydra A

Galaxy Clusters

MS0735.6+7421

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Cluster RadioHalo

A754Kassim et al. ‘01

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Bachigi et al. 2006, Science

Cluster Accretion Shocks (?)

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Beyond Clusters…. (???)

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Kronberg et al. 2007, ApJ

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Part II:

Origin of Extra-Galactic Magnetic Fields

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Numerical simulations- cold dark matter cosmology = 0.73, DM = 0.27, gas = 0.043, h=0.7, n = 1, 8 = 0.8 without/with gas cooling- computational box: (100h-1 Mpc)3

10243 cells for gas and gravity, 5123 DM particles, x = 97.7 h-1kpc

Ryu et al. 2005

= 1 – 104 <> and higher

Baryon DensityVorticity Generation

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Cosmic Energy Flow

Gravity

Stars, galaxies, galaxy clusters,

large scale shocks, etc.

IGM

“Feedback”MechanicalChemicalThermal

Non-ThermalMagnetic

collapse

Black Holes

RadiationKinetic WindsMagnetic fields

108 Msun 1062 ergs

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Part III:

Astrophysical Jet Modeling and Interaction with ICM

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“flux core: & Iz”(“helix/jet”)

toroidal Bfrom Iz(“lobes”)

confinement(B2

/8 ~ pgas)

Jz @ t = 10global current flow

(Li et al. 2006, Nakamura, Li, Li 2006, 2007)

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Hydra A

Diehl, Li, et al. 2007

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QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

QuickTime™ and aTIFF (Uncompressed) decompressor

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Zavala & Taylor 20053C273

Differential FRM

Is there current in jets?

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Part IV:

Magnetic Fields Injected from SMBHs

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Growing “cherries” on cosmic trees …

Mpc/(1+z)Johnson et al. in preparation

z=2

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Mpc/(1+z)

B=0.1 G

Li et al. 2007

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Part V:

Cosmological MHD Simulation of Cluster

formation with Magnetic Fields

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AMR MHD Cluster Formation Simulations

Same simulation with radiactive cooling, star formation and star formation feedback, uniform initial magnetic fields of 1e-9 G in y direction.

Projected logarithmic baryon density, refined to level 2,4,6 and 8. Each plot has a resolution of 512x512 zones. Best spatial resolution is 7.8125kpc/h

256Mpc/

h4M

pc/h

ΛCMD model, Ω=1, ΩΛ=0.7, Ωb =0.04, h=0.7,and box size = 256 Mpc. Root grid is 1283,refined by 2 to level 8, simulation is from z=30 to z=0.

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Magnetic Energy Density Evolution

256Mpc/

h

4Mpc/h

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SZ Effect: y-parameter

256Mpc/

h

4Mpc/h

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AMR MHD Cluster Formation SimulationsImagines of cluster center(1Mpc/h)

Gas density SZ_y

Magnetic energy density Rotation measurement

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AMR MHD Cluster Formation SimulationsΛCMD model, Ω=1, ΩΛ=0.7, Ωb =0.04, h=0.7,and box size = 256 Mpc/h. Root grid is 1283,refined by 2 to level 8, simulation is from z=30 to z=0. No initial magnetic fields

Imagines of projected baryon density of inner 4 Mpc/h at z=0, left is from MHD solver and right is from ppm solver

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AMR MHD Cluster Formation SimulationsΛCMD model, Ω=1, ΩΛ=0.7, Ωb =0.04, h=0.7,and box size = 256 Mpc/h. Root grid is 1283,refined by 2 to level 8, simulation is from z=30 to z=0. No initial magnetic fields

Y parameter of SZ Effect of slice of inner 4 Mpc/h at z=0, left is from MHD solver and right is from ppm solver

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AMR MHD Cluster Formation SimulationsΛCMD model, Ω=1, ΩΛ=0.7, Ωb =0.04, h=0.7,and box size = 256 Mpc/h. Root grid is 1283,refined by 2 to level 8, simulation is from z=30 to z=0. No initial magnetic fields

X-ray luminosity of of inner 4 Mpc/h at z=0, left is from MHD solver and right is from ppm solver

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Some Key Problems1. Diffused Radio Emission: Distribution and strength of

cosmic magnetic fields, seeding from first stars, dwarf galaxies, AGN feedbacks, or (turbulent) dynamo.

2. Differential FRM of jet pc-kpc scale: is there current?3. Clusters as magnetic field laboratories: Structure

formation, AGNs, heating, mixing, etc.4. Physical state of IGM: impact on galaxy formation? 5. UHECR transport?6. Does magnetic energy flow destroy the statistics of Lyman-alpha forests?