1. Into the Engine: GRMHD Simulations
Jonathan McKinney
Stanford/KIPAC

2. Black Hole Accretion Systems
1038erg/s
M~10M¯
1044erg/s
M~107M¯
1052erg/s
M~3M¯
Mirabel & Rodriguez (Sky & Telescope, 2002)

3. GRB Jets Issues: Launch: - vs. MHD Jets Jet: Fireball vs. EM
Prompt: Shocks vs. EM dissipation
BH-BH: Clean GW signal – informs about gravity
astrogravs.nasa.gov/docs/catalog.html
Taylor et al. 2004
Fireball Model (Sari, Piran, Meszaros, Rees >1993)
EM Model (Lyutikov & Blandford 2003)

4. AGN Jets Jet Issues: Some Dark (non-dissipative?)
Junor/Biretta/Walker
Jet Issues:
Some Dark (non-dissipative?)
Origin of FRI vs. FRII Classes?
Radio Loud-Quiet Dichotomy?
Blazars (-ray and TeV Emission?)
Implication for GRBs?
Pictor A
M87 movie: every 3 weeks in 2007.
Fanaroff and Riley
Mrk501
Cygnus-A
3C31

5. Example Solutions to AGN Dichotomy
Changes in Field Geometry
Non-Dipolar Fields (Beckwith/McKinney ‘09)
Changes in Jet Confinement
Triggers Magnetic Switch (Meier et al. ’97, Komissarov 2009)
Variation in amount of BH/Disk Magnetic Flux
Flux trapping (Reynolds 06, Garafalo ‘09)
Magnetically-dominated disk (Igumenshchev ‘09)
Difference in Disk Thickness (Meier ’01)
Application to GRBs? (flux trapping: Proga ‘06)

6. BH X-Ray Binaries Questions:
Belloni et al.
Orosz
Mirabel & Rodriguez
Questions:
What determines the Spectral (and Temporal) States?
How are X-ray binary states related to AGN and GRBs?

7. Disk-Jet Coupling Effects
Role of Large-Scale vs. Small-Scale Magnetic Fields?
Disk dominates BH in powering jet? (Ghosh & Abramowicz 1997;Livio, Ogilvie, Pringle 1999)
Weak Magnetic Field Threads BH? (Ghosh & Abramowicz 1997;Livio, Ogilvie, Pringle 1999)
Jet Power / a2 (weak dependence)? (Blandford & Znajek 1977 vs. McKinney 2005)
BZ77
Blandford & Payne ‘82
MacDonald & Thorne ‘82

8. 3D GRMHD Simulations Issues: Jet from Disk or BH?
Unstable to Turbulence in Disk?
Unstable to Accreting Disordered Field?
Dipolar
Quadrupolar

9. Quadrupolar Field Jet Fails
Magnetic field geometry crucially determines existence of jet
Fully 3D GRMHD Jet Simulations
McKinney & Blandford (2009)

10. Dipolar Field Jet Succeeds
Suggests jets require accretion of organized field
Fully 3D GRMHD Jet Simulations
McKinney & Blandford (2009)

11. X-Ray Binaries: Origin of States?
Quadrupolar
Dipolar
No Ordered Field
Igumenshchev (2009) McKinney & Blandford (2009)

12. BH Engine Flow Structure
Poynting Jet
“Matter” Jet
CORONA: MA~EM
FUNNEL: EM dominated
JETS: Unbound, outbound flow
McKinney & Gammie (2004)
DeVilliers, Hawley, Krolik ( )

13. Field becomes super-equipartition for high spin
Komissarov & McKinney (2007)
McKinney (2005)
Tchekhovskoy, Narayan, McKinney (2010)

14. Jet Propagation Stability: Kink
|m|=1 most dangerous: Center-of-mass shifted L R RL j z B
Kruskal-Shafranov non-rel. criterion
Tomimatsu (2001) ~rel. criterion
Narayan et al. (2009) rel. criterion
Expansion & Finite Mass-loading: Jet goes out of causal contact
McKinney (2006) Narayan et al. (2009)

15. Dipolar
Field
Dipolar Field Jet Succeeds:
Relativistic Rotation, Expansion, Non-linear Saturation

16. Applications to GRBs 1 Setup: Collapsar Model 2D GRMHD
Start with BH and collapsing star
Realistic EOS
Neutrino Cooling (no heating)
Strong and Ordered Magnetic Field
Result:
BZ-effect drives MHD jet
Still no high Lorentz factors
3D and resolution needed to study boundary instabilities
Komissarov & Barkov ( )

17. Applications to GRBs 2 Problem: Any Resolution?
Ultrarelativistic motion:  ~ 400 (Lithwick & Sari 2001, Piran 2005)
Afterglow Breaks: » 2-20
Standard MHD Jet Models give » 1
Any Resolution?
Stellar Break-Out Rarefaction
”Achromatic break” in the light curve when (µ)t ≃ 1
Light curve modeling gives µ =2 { 10
1 day
10 days
100 days
Tchekhovskoy, Narayan, McKinney (2010)

18. Jet Break-Out log() µ = 2 = 500 µ = 20 1 2 3 µ = 0.02 µ = 0.041 2 3
log()
= 100
µ = 0.02
µ = 2
= 500
µ = 0.04
µ = 20
star BH BH
Tchekhovskoy, Narayan, McKinney (2010)
Komissarov et al. (2010)

19. Effects of Time-Variability
Idea:
Time-variable Jet leads to magnetized jet bubble separated by a near-vacuum if envelope cannot relax fast enough to fill-in hole left by the jet
Problem:
Compact object + disk generate wind and fills-in hole when jet is turned off
No forward rarefaction would occur
Solution: Transient suppression of jet+wind by ram pressure of fresh in-falling material
Granot et al. (2010) & Lyutikov (2010)

20. GRMHD Simulations of Thin Disksz R
Results:
1) Thin Disk theory (Novikov & Thorne 1973) holds fairly well as long as H/R. 0.07
2)  and shear stress not good indicators of dissipation or transport near ISCO or horizon
3) Assumed initial Magnetic Field controls level of deviations from Thin Disk Theory PA
Penna, McKinney, et al. (2010)
Shafee, McKinney, et al. (2008)

21. Review: BH Driven Jet becomes Relativistic if Ordered Field
GRB Jets: Stellar Break-out Leads to À 1 » 20
Disk Driven Wind-Jet is Weakly Relativistic
Mass-Loaded by Disk Turbulence
Jet Stability Maintained by (e.g.)
Relativistic Rotation of Field Lines & Expansion of Jet
Non-linear Saturation
Standard (Novikov-Thorne) Thin Disk theory holds
Much prior work on GRB accretion solutions are ~ valid