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1
Astrophysical
Jets
Astrophysical
Jets
Mario LivioSpace Telescope Science Institute
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Which Systems Have Highly Collimated Which Systems Have Highly Collimated JetsJets??
Object Physical System
Young Stellar Objects Accreting Star
HMXBs Accreting NS
X-ray Transients Accreting BH
LMXBs Accreting NS
Supersoft X-ray Sources Accreting WD
Symbiotic stars Accreting WD
Pulsars (?) Rotating NS
Planetary NebulaeAccreting Nucleus or Interacting Winds
Stellar
Object Physical System
AGNAccreting Supermassive BH
GRBs Accreting BH
Extragalactic
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Disks around Young Stars STScI-PRC99-05bDisks around Young Stars STScI-PRC99-05b
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M87: AGN from M87: AGN from 200,000 light 200,000 light years years to 0.2 light yearto 0.2 light year
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Superluminal Superluminal Motion in M87 Motion in M87
HST-1HST-1
• Do FR I radio galaxies have relativistic jets like BL Lacs?
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““Superluminal” sourcesSuperluminal” sources
• GRS 1915+105V ~ 0.9c
• Extragalactic jets showV > 0.995c
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Gamma Ray BurstsGamma Ray Bursts
Fruchter et al. 2006
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STScI-PRC99-32
Southern Crab NebulaHe2-104
SymbioticsSymbiotics
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Planetary Nebulae STScI-PRC97-Planetary Nebulae STScI-PRC97-38b38b
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Point-Symmetric Planetary Point-Symmetric Planetary NebulaeNebulae
• IC 4634
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Point-Symmetric Point-Symmetric Planetary NebulaePlanetary Nebulae
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Point-Symmetric Planetary Point-Symmetric Planetary NebulaeNebulae
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Vermeulen et al. 1993
SS 433SS 433
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Supersoft X-Ray Source RXJ 0513-Supersoft X-Ray Source RXJ 0513-6969
Southwell et al. 1996
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Recurrent Recurrent Novae Novae and and SymbioticsSymbiotics
U Sco (1999)
Lépine, Shara, Livio & Zurek 1999
Hillwig, Livio & Honeycutt 2004
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Pulsar JetsPulsar Jets
Chandra
Crab Pulsar
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Vela Pulsar
Chandra
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Do Jets Do Jets RequireRequire an Accretion an Accretion Disk?Disk?
• What are the absolutely necessary ingredients for the mechanism of jet acceleration and collimation?
Have disk?
YSOs Yes (but maybe funnels?)
PNe Yes (but maybe funnels?)
SSS Yes
H/LMXBs Yes
BHXTs Yes
GRBs We don’t know
AGN Yes (?) (but maybe ion torus and surrounding gas pressure? Fabian & Rees 1995)
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[OI] [OI] 6300 Profiles 6300 Profiles for T Tauri Starsfor T Tauri Stars
Redshifted component not seen because of disk.
Edwards et al. 1987Livio & Xu 1997
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X-Ray Spectroscopy of Accretion X-Ray Spectroscopy of Accretion DisksDisks
• MCG-6-30-15 (Tanaka et al.)• Gravitational redshift plus Doppler shift
• Evidence that ~ max = 1/2 m
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Do Jets Require an Accretion Do Jets Require an Accretion Disk?Disk?
YesYes
“Interacting winds”, “ion torus”, Pulsars, need more work
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Do Accretion Disks Do Accretion Disks RequireRequire Jets or Jets or Outflows?Outflows?
• Are outflows/jets the main mechanism for transport/removal of angular momentum (Königl; Pudritz & Norman ’86; Li ’96)?
• Angular momentum carried by wind
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Do Accretion Disks Do Accretion Disks RequireRequire Jets or Jets or Outflows?Outflows?
Angular momentum that needs to be removed from
disk
For rA ~ 10r, only 1% of the accreted mass needs to be lost in wind.
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Behavior of Disk Radius During Behavior of Disk Radius During Dwarf Nova OutburstDwarf Nova Outburst
• At outburst, matter diffuses inward. Angular momentum of that matter is transferred to outer parts of the disk.
• Radius expands• Observations• OY Car, HT Cas, Z Cha
(Harrop-Allin & Warner ’96)
• Disks in OY Car, HT Cas and Z Cha larger in outburst.
U Gem
Smak 1984
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Behavior of Disk Behavior of Disk RadiusRadius During During Dwarf Nova OutburstDwarf Nova Outburst
Theory, disk instability
Ichikawa & Osaki 1992; Livio & Verbunt 1988
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Do accretion disks Do accretion disks requirerequire jets or jets or outflows for angular momentum outflows for angular momentum
removal?removal?
I don’t think so.
• Observations of rotation in jets and bipolar outflows are badly needed (velocity gradients).
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Other Clues on JetsOther Clues on JetsJet Origin Object Example Vjet/Vescape
YSOs HH30, 34Vj ~ 100-350km/s
Vesc ~ 500km/s
~1
AGN M87; radio sources >~ 3; <~ 10
~1
GRBs ~ 100 ~1
XRBs SS 433; Cyg X-3Vj ~ 0.6c
~1
XRTs GRO 1655-40GRS 1915+105
Vj >~ 0.9c
~1
Pne Fliers, AnsaeV ~ 200km/s
~1
SSS 0513-69Vj ~ 3800km/s
~1
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• Jets originate from the center of the accretion disk!
• Models which work at all radii are probably not the “correct” ones, (e.g. self similar).
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Black Hole JetsBlack Hole Jets
Two states: (i) dissipation
and disk luminosity,
(ii) bulk flow and jet.
Livio, Pringle, King 2003, 2004; Mirabel 1993, 1998; Fender 2003; Fabian 2002, 2003
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New TimescaleNew Timescale
Timescale for jet
tj ~ td2R/H
1/f power spectrum below a break frequency.King, Pringle, West, Livio 2004
Hujeirat, Livio, Camenzind, Burkert 2003
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Which ingredients play a major role in the acceleration and
collimation?
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Ingredients which may Ingredients which may notnot be absolutely necessarybe absolutely necessary
YSOs AGN XRBs SSS Pne (CVs)
Central object near break-up rotation
No ? No, ? ? No ?
Relativistic central object
No Yes Yes No No No
“Funnel” No (?) No (?)
No (?) No Yes (?)
No
L >~ LEdd (Radiation pressure)
(wind can be driven;
Murray et al. 1997)
No No No Yes Yes No
Extensive hot atmosphere
(gas pressure)
Yes (?)
Yes No No Yes (?)
No
Boundary layer Yes (?)
No ? Yes (?)
Yes (?)
Yes (?)
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What Does Work?What Does Work?
A reasonably ordered large-scale magnetic field threading the disk!
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Magneto-Centrifugal Jet Magneto-Centrifugal Jet Acceleration and CollimationAcceleration and Collimation
1. Acceleration like a bead on a wire up to the Alfven surface.
2. Acceleration optimal around inclination of 60° (Blandford & Payne 1982; Meier et al. 1997).
€
B2
8π> ρν 2
€
ρν 2 >B2
8π
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Collimation Outside Alfven Collimation Outside Alfven SurfaceSurface
Collimation by hoop stress?
BUT
Kink Instability
Heyvaerts & Norman 19962 2( ) /8zB Bφ π−
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Poloidal CollimationPoloidal Collimation
Necessary Conditions1. Rdisk/Robject = Significant number of decades
2. Bz largest at inner disk but largest at outer disk e.g. Bz ~ (r/Rin)-1
Good collimation obtained forRAlfven ~ Rdisk
Konigl & Kaatje 1994; Spruit 1996
ConsequencesMinimum opening angle of jet
min ~ (Rin/Rout)1/2
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M87M87
Junor, Biretta, Livio 1999
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Relativistic OutflowRelativistic Outflow
Magnetic flux tubes across horizon propel relativistic outflow.No collimation
Koide 2004
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Are There Additional Are There Additional Ingredients?Ingredients?
1. Why are there radio-loud and radio-quiet AGN?
2. Why do CVs appear not to produce jets while PNe nuclei and SSS do?
3. How can pulsars produce jets?
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ConjectureConjecture
• The production of powerful jets requires an additional heat/wind source.
• Solutions to transsonic flow in disk corona (Ogilvie & Livio 1997, 2000) for strong B a potential difference exists even for i > 30 ( ~ B4).
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Energy Extraction from Spinning Energy Extraction from Spinning HolesHoles
• Penrose Process– Negative energy orbits within
“ergosphere”.– Need fortuitous collision or
deus ex machina.
• Electromagnetic Extraction– Magnetic fields supported
by external current interacts with “conducting” horizon.
– Energy extracted to jet and disk.– Corotating observer sees energy
flow across horizon.– Conserved outward flow of energy, angular
momentum in non-rotating frame.– Reduce m; increase m0.
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Radio Loud vs. Radio Quiet AGNRadio Loud vs. Radio Quiet AGN
Sikora et al. 2006Xu, Baum & Livio 1999 Rawlings 1994
Central engineparameters:
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Spins of Black Holes?Spins of Black Holes?
• RISCO, a*, determined on the basis of x-ray data.
• Study of plunging orbits important.
McClintock et al. 2006Shafee et al. 2006
Zhang, Cui & Chen 1997
Source M (Mʘ) a*
1655-40 6.3+-.27 ~0.7
1543-47 9.4+-1.0 ~0.8
1915+105 14+-4.4 >0.98
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Critical ObservationsCritical Observations
For the General Picture1. Reliable determinations of 2. Determinations of the collimation scale
in all classes of objects.3. Long-term monitoring for variablity
patterns in double-peaked emission lines in AGN. Power spectra.
4. Detection and measurement of rotation and of toroidal magnetic fields in jets and bipolar outflows.
5. More evidence for precession.6. Breaks in afterglows of GRBs.
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Critical ObservationsCritical Observations
For the Conjecture1. Searches for jets in other SSS, in PNe, in
other XRTs (during flares, e.g. A0620-00, GS2023+338, GS 1124-683, Cen X-4, AQL X-1), and other symbiotic systems, in CVs!
2. Determination of black hole masses in AGN.3. Determination of black hole spins in AGN
(e.g., through Fe Kline profiles).4. Determination of black hole spins in stellar
mass black holes.5. Determine whether pulsars can generate
highly collimated jets.