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5 iv 2012 CIFAR 1
(How) Do Spinning Holes make Jets?
Roger Blandford,KIPAC
Stanfordwith
Jonathan McKinney (KIPAC, Maryland)Sasha Tschekovskoy (Princeton)
Nadia Zakamska (JHU)
Sackler Lecture Princeton22 iv 2010
Cygnus A
3C31
3C75
Extragalactic Jets
Pictor A
M87
NGC 326
5 iv 2012 CIFAR
Pictor A
Current FlowNonthermal emission is ohmic dissipation of current flow?
Electromagnetic Transport1018 not 1017 ADC not ACNo internal shocksNew particle acceleration mechanisms
Pinch stabilized by velocity gradient?
Equipartition in core
Wilson et al
3
5 iv 2012 CIFAR 4832AGN+268Candidates+594Unidentified!
3C454.3
5 iv 2012 CIFAR 5
2x1050erg s-1 isotropicBreaks due to recombination radiation?
Marscher
Radio Monitoring (OVRO 40m)
• ~1500 sources• Radio and g-ray active• Spectrum, polarization
5 iv 2012 CIFAR 6
Max-Moerbeck etal
Rapid MAGIC variation
• PKS 1222+21– 10 min
• MKN 501– 2min?
• PKS 2155-304– “Few hr”?
5 iv 2012 CIFAR 7
PKS 1222+21 (Aleksik et al)
How typical?How fast is GeV variation?
3C 279: multi-l observation of g-ray flare
• ~30percent optical polarization => well-ordered magnetic field
• t~ 20d g-ray variation
=> r~g2ct ~ pc or tdisk?
• Correlated optical variation? => common emission site
• X-ray, radio uncorrelated => different sites
• Rapid polarization swings ~200o => rotating magnetic field in dominant part of source
Abdo, et al Nature, 463, 919 (2010)
r ~ 100 or 105 m?
5 iv 2012 8CIFAR
PKS1510+089
(Wardle, Homan et al)
5 iv 2012 CIFAR 9
z=0.36• Rapid swings of
jet, radio position angle• High polarization ~720o (Marscher)
• Channel vs Source• TeV variation (Wagner / HESS)
• EBL limit• rmin ; rTeV>rGeV
(B+Levinson)
bapp=45
Jansky VLA (New Mexico)
5 iv 2012 CIFAR 10
27 antennae, 1-50GHz (+0.08GHz)10xsensitivity… 50 mas resolution
SS433 and the W50 nebula
Chandler Outflows, Winds, and Jets Workshop, March 2012
11
ALMA First results
5 iv 2012 CIFAR 12
Atacama desert 5km high66 telescopes, 300m- 1cm eventually ~ 5mas resolution
CIFAR 135 iv 2012
B
M
Rules of thumb:
~ F B R2 ; V ~ W F; I~ V / Z
0; P ~ V I
PWN AGN GRB
B 100 MT 1 T 1 TT
/2 W 10 Hz 10 Hz 1 kHz
R 10 km 10 Tm 10 km
V 3 PV 300 EV 30 ZV
I 300 TA 3 EA 300 EA
P 100 XW 1 TXW 10 PXW
Unipolar Induction
UHECR!
€
m =m0
1 − β2; β = Ωm < 2−1/ 2
5 iv 2012 CIFAR
Intermediate Mass Supply
• Thin, cold, steady, slow, radiative disk
• Specific energy e = -Wl/2
€
G − ′ M l = const ≈ 0
dL
dr=
d(ΩG − ′ M e)
dr≈ 3 ′ M
de
drG
Energy radiated is 3 x the local energy loss14
5 iv 2012 CIFAR
Low, High Mass Supply
• M’<<M’E, tenuous flow cannot heat electrons and cannot cool
• M’>>M’E, dense flow traps photons and cannot cool • Thick, hot, steady, slow, adiabatic disk• Bernoulli function: b =e+h
€
G − ′ M l ≈ 0
ΩG − ′ M b ≈ 0
⇒ b ≈ −2e > 0
G
Energy transported by torque unbinds gas => outflow
ADiabatic Inflow-Outflow Solution15
5 iv 2012 CIFAR 16
W
x
.
Dipolar or Quadrupolar?
Even field Odd current
Lovelace, Camenzind, Koide, RB
x x x
Odd field Even current
Also prograde vs retrograde?
5 iv 2012 CIFAR 17
CIFAR 18
“Observing” Simulated Jets
Synchrotron Radiation
€
IνΩ(ν , to) = dzδ 2 j'ν 'Ω'∫ (ν /δ, to)e− dzδ −1κ '(ν /δ ,to )∫
δ =1
γ(1−Vz)
Sν (ν , to) =1
ad2dxdyI∫
νΩ(ν , to)
5 iv 2012
• We know P’, B’, N’, V on grid• Work in jet frame• Rotate spatial grid so that observer along z direction• Shear in t – z space introducing to=t-z
• Make emission model• eg j’ ~ P’ B’3/2 ’n -1/2; ’~ k P’B’2 ’n -3
• Polarization – perpendicular to projected field in cm frame
t
z
to
z’
z
Vß
“Observing” Simulated Jets
Inverse Compton Radiation• Work in jet frame
• Compute incident radiation along all rays from earlier observer times
• Compute j nW directly
5 iv 2012 CIFAR 19
Observer
sq
r
[r-s,to-s(1-cosq)]
z
“Observing” Simulated Jets
Pair Opacity
5 iv 2012 CIFAR 20
€
κ = dsdΩdνNνΩ (r r −
r s ∫ , to − s(1− cosφ),ν )σ PP (1− cosφ)
• External and internal radiation• Internal radiation varies
5 iv 2012 CIFAR 21
Disk
Light
Optical emission from jet with g ~ 3-4
Zakamska, RB & McKinney in prep
Quivering Jets• Observe g-rays (and optical in
3C279)• Gammasphere tgg~1, 100-1000m ~
Eg• Rapid variation associated with
convected flow of features (2min in Mkn 501)
• Slow variation associated with change of jet direction on time scale determined by dynamics of disk (precession?) or limited by inertia of surrounding medium or both as with m=1 wave mode.
5 iv 2012 CIFAR 22
5 iv 2012 CIFAR 23
Total Flux and Degree of Polarization
Summary
5 iv 2012 CIFAR 24
• New observations of AGN and stellar relativistic jets• Fermi, MAGIC, optical polarimetry, JVLA, ALMA…• 3D Black Hole MHD simulations possible for >106 m• Efficient energy extraction• Powerful winds• Jet Disk Oscillations• “Observe” simulated relativistic jets• Radio, g-rays, optical polarization
Dynamical elements • Bulk flow• Shocks• Shear flow • Plasmoids, flares, minijets,magnetic
rockets…– Lorentz boosting
• Precession– Disk– m=1 instability
• Turbulence
5 iv 2012 CIFAR 25
Each of these elements changes the field and the particles
Pair vs Ion Plasmas
• Pairs must be heavily magnetized to avoid radiative drag
• Circular polarization, Faraday rotation/pulsation
• Expect? pairs, field todecrease, ions to increase along jet
5 iv 2012 CIFAR 26
CIFAR 275 iv 2012
Particle acceleration in high s environments
• Internal shocks are ineffectual• Reconnection can be efficient
– E>B??• Shear flow in jets
– Full potential difference available particles accelerated when undergo polarization drift along E
– UHECR (eg Ostrowski & Stawarz, 2002)
• Fast/intermediate wave spectrum– Nonlinear wave acceleration(Blandford 1973…)
• Mutual evolution of wave cascade and particle distribution function– Charge starvation (eg Thompson & Blaes 1997)
• Force-free allows E>B - catastrophic breakdown
Particle Acceleration
5 iv 2012 CIFAR 28
• S-C-1 transition quite high in BLLacs• “Theoretically” Eg<a-1 mec2~60MeV• cf Crab Nebula, UHECR• Large scale electric fields• Lossy coax??• Follow particle orbits.• Which particles carry the current• Is the momentum elctromagnetic?
5 iv 2012 CIFAR 29
Faraday Rotation
Broderick & McKinney
Signature of toroidal field/axial current
Rotation from sheath
Observations ???
Simulation
5 iv 2012 CIFAR 30
Telegraphers’ Equations
5 iv 2012 CIFAR 31
Relativistic Reconnection
McKinney & Uzdensky
• High s flow• Hall effects may save Petschek mechanism• Anomalous resistivity?• Also for AGN
Petschek
GRBs?
5 iv 2012 CIFAR 32
Inhomogeneous Sources • Radio synchrotron
photosphere, r ~ l– Doppler boosting
• Compton gammasphere, r ~ E?– Internal, external radiation– Test with variability, correlation
• Electron acceleration – >100 TeV electrons
5 iv 2012 CIFAR 33
S
n E
S C-1
Summary• Protostars->GRBs->Quasars• Location, mechanism, collimation,
origin…? • FGST+TeV+multi-l observations of blazars• Major monitoring campaigns• Rotating polarization, rapid variation• GRMHD simulations answering basic
questions about flows, dynamics• “Observations” of simulations now
possible to (in)validate simple phenomenological models and test against data and “best” examples. 5 iv 2012 CIFAR 34
CIFAR 35
3D GRMHD Simulations• >105m Kerr-Schild, HARM, 512x768x64
– Quasi-steady state
• Build up flux –back reaction– Thick spinning disks, suppress MRI– Dipolar (not quadrupolar) makes jets
• Efficient extraction of spin energy-> jets– Prograde (not retrograde) more efficient
• Wind outflows– Poorly collimated, slow
• QPOs, – ~70m, a~ 0.9; Q~100 (jet) ~3 (disk)
• Strong intermittency– Helical instability m=1
5 iv 2012
McKinney, RB; McKinney, Tschekovskoy, RB
Tschevoskoy et alTalk on MONDAY