Jet Formation and Propagation in Black Hole Accretion
Jet Formation and Propagation in Black Hole Accretion Systems Speaker: Jonathan C. Mc. Kinney Ann Arbor : Dec 17, 2005 Mc. Kinney (2005) (a, b, c) Mc. Kinney & Gammie (2004) Gammie, Shapiro, Mc. Kinney (2004) Gammie, Mc. Kinney, Toth (2003)
Why Study Jets? • “Pathological” energy-momentum transport • Accretion disks common • Jets produced in: – YSOs, WDs, NSs, BHs • Supersoft X-ray sources, symbiotic stars, classical novae, but not CVs • Not so “pathological” – Non-negligible to energy and radiative budget
Black Hole Accretion Systems 1038 erg/s 1044 erg/s 1052 erg/s M~10 M¯ M~107 M¯ M~3 M¯ Mirabel & Rodriguez (Sky & Telescope, 2002)
Outline • Black hole energy extraction • Numerical GRMHD model – Segmented accretion flow structure – Disk/Wind/Jet field geometries – Large scale Poynting jet • Piece-wise self-similar • Inner parabaloidal jet and conical exterior
Kerr Black Hole Ergosphere Properties: • Spin: J • Mass: M • Up to ~30% of mass energy extractable Examples: Event Horizon • GRB with M» 3 M¯ E» 1054 ergs L» 5£ 1052 erg s-1 • AGN with M» 108 M¯ E» 5. 6£ 1061 ergs L» 3£ 1010 L¯ s-1 BH Ergo
Blandford & Znajek Poloidal Field Assumptions: • Kerr BH (small j) • Force-free ED or EM>MA • Axisymmetric Disk • Stationary Solve: Find: • Force-free equations (Jx. B=0) • Outward Flux of Energy OR • Magnetic Field Structure • Conservation equations (monopole or parabolic)
GRMHD Assumptions: Poloidal Field • Kerr BH • Matter + fields (MA+EM) • Ideal MHD, ideal gas Disk • Axisymmetric • Nonradiative • Initial hydro-equilibrium torus • Time-dependent Solve: Find: • Conservation equations • Mass density & internal energy • Induction equation with r¢B=0 constraint • Velocity & magnetic field
M 87 Jet Formation Junor (1999) & Biretta (1999, 2002)
Numerical Model Log Mass Density Parameters:
Initial State Poloidal Field
Final State
Mass and Field Structure Log of mass density Poloidal Field • Evacuated polar region • Ordered polar field • Turbulent equatorial region • Random equatorial field
DISK: Matter dominated PLUNGING: MA~EM er” Je t “Matt Poyntin g Jet Flow Structure CORONA: MA~EM FUNNEL: EM dominated JETS: Unbound, outbound flow
Common Field Lines Balbus & Hawley (MRI) [1] Gammie & Krolik [2, 3] Effect of reconnections [4, 5] Lovelace or Blandford-Payne [6, 7] Konigl & Vlahakis [6, 7, ~9] Uzdensky, Matsumoto [8] Blandford & Znajek [9] 9 7 Final State 5 4 3 1 2 Avg. Common Temporary Never Time 8 6 State
Large Scale Jet • Outer Radius : 104 GM/c 2 – 0. 001 AU for XRBs – 0. 1 R* or 1010 cm for GRB – 1. 4 pc for M 87 • Final Time : 104 GM/c 3 – 0. 1 -1 s for XRBs – 0. 1 s for GRB – 5 yrs for M 87
Large Scale Jet AGN/XRB-like GRB
Density and Field: Large scales
Log of Lorentz factor
Kink Stability • Kruskal-Shafranov criterion for instability • Tomimatsu (2001) criterion for instability (slow rotation approximation)
Piece-wise SS Small radius (r<~100 M) Large radius
Characteristic Surfaces B /Br=1 Field Lines O-Fast Light “Cylinder” O-Alfvén O-Slow B /Br=1 I-Alfvén I-Fast / Horizon rin vr=0 I-Slow Null ( F= ZAMO) Ergosphere
Field Geometry
GRMHD Summary • Segmented flow structure • BZ-like funnel region • Self-consistent, relativistic jets • Poynting outflow is Large • Matter+Poynting outflow » 1 -3
- Slides: 25