Numerical Simulations of Relativistic Jets

1
Numerical Simulations of Relativistic Jets

• Peng Wang
• KIPAC

2
Overview

• Why we study jets
• How we study jets the codes
• Some (preliminary) results on 3D relativistic
  hydro jet propagation Jet production by GRMHD
  effect Binary black hole evolution

3
Why jets are interesting

• GLAST will see up to 104 blazars which are
  relativistic jets pointed at us (Blandford Rees
  1978).
• Ideal lab for studying the physics of
  relativistic (magneto-)hydro turbulence and
  particle acceleration
• Provide constraints on the center engine
• AGN feedback are crucial for galaxy formation
• Thus, jet is a hot topic. GLAST will make great
  progress in nailing down whether jet is really
  hot!
• We are simulating them so as to use the data to
  answer the fundamental questions about how they
  work.

4
The codes

• The complexity of the problem requires a
  multi-scale multi-codes approach
• Large scale jet propagationRenzo 3D adaptive
  mesh refinement (AMR) relativistic hydro code
  (PW, Tom Abel, Weiqun Zhang)
• Jet production by GRMHD effectNVWA 3D GRMHD
  code (Weiqun Zhang, PW)
• Black hole accretion disk at parsec
  scaleEnzo-MHD 3D AMR Newtonian MHD code (PW,
  Tom Abel)
• See also Matt Turks talk for other applications
  of AMR codes, e.g. in cosmological structure
  formation.

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Jet propagation

• Problem setupLorentz factor 5 jet injected
  into a medium in pressure equilibrium with the
  jet.
• Demonstrate the development of turbulence in
  jet cocoons.

Renzo code PW, Tom Abel Weiqun Zhang, ApJS 2008
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Jet production by BZ effect

• Problem setupA equilibrium thick disk with a
  tiny seed magnetic field around a Kerr black
  hole with spin 0.9
• Demonstrate the development of
  magneto-rotational instability in the disk and
  production of a Poynting flux dominated jet by
  the Blandford-Znajek mechanism.Agrees with many
  other groups usingthe same setup.

NVWA code Weiqun Zhang PW
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Jet collimation acceleration by wind

• Problem setup A non-relativistic wind
  withpolar density stratification isinjected
  spherically.
• Demonstrate that the interactionwith the denser
  outer part can lead to efficient acceleration
  collimation (up to Lorentz factor11 in this
  particular run).

NVWA PW, Zhi-Yun Li Weiqun Zhang
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Future direction comparing simulations to
observations

• Perform ray-tracing through the simulated data to
  predict the observed gamma rays and radio flux.
• Also need to add magnetic field to large scale
  propagation study in order to compare to GLAST
  observation.

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A Possible LSST candidate Circumbinary Black
Hole Disk

• Problem setupA binary massive black hole
  embedded in a gaseous disk.
• Emission from the inner diskmay provide EM
  counterpartto LISA observationsthat can be
  observed by LSST.

Enzo-MHD PW Andres Escala
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Summary

• Forthcoming observations from GLAST LSST is
  likely to advance significantly our understanding
  of black hole/jet systems.
• Exciting observations need exciting simulations.