Theory Mario Livio Space Telescope Science Institute Which Systems Have Highly Collimated Jets Object Physical System Young Stellar Objects Accreting Star HMXBs Accreting NS or BH Xray Transients ID: 778598
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Slide1
Astrophysical Jets:
Observations and Theory
Mario Livio
Space Telescope Science Institute
Slide2Which Systems Have Highly Collimated Jets?
Object Physical System
Young Stellar Objects
Accreting Star
HMXBsAccreting NS or BHX-ray TransientsAccreting BHLMXBsAccreting NSSupersoft X-ray SourcesAccreting WDSymbiotic starsAccreting WDPulsars (?)Rotating NSPlanetary Nebulae (?)Accreting Nucleus or Interacting Winds
Stellar
ObjectPhysical SystemAGNAccreting Supermassive BHGRBsAccreting BH
Extragalactic
Slide3Jets in Young Stellar Objects
Slide4HH1 Jet 1994-2007
Slide5HH 901 Carina Nebula
Slide6Jet in M87: From
60 kpc to 0.06 pc
Slide7Superluminal Motion in M87 HST-1Do FR I radio galaxies have relativistic jets like BL Lacs?
Slide8“Superluminal” sources
GRS 1915+105V ~ 0.9cSome extragalactic jets showV > 0.995c
Slide9Gamma Ray Burst Hosts
Slide10STScI-PRC99-32
Southern Crab Nebula
He2-104
Symbiotic Systems
Slide11Jets in Planetary Nebulae?
NGC 7009
NGC 6543
NGC 3918
NGC 6826NGC 5307
Slide12High mass x-ray binaries
SS 433
Slide13Supersoft X-Ray Sources
RXJ 0513-69
Slide14Pulsar Jets (?)
Chandra
Crab Pulsar
Vela Pulsar
Chandra
Slide15Do jet-producing systems have accretion disks?What are the
absolutely necessary ingredients for the mechanism of jet acceleration and collimation?YSOs
Yes
SSS
YesH/LMXBsYesBHXTsYesGRBsWe don’t knowAGNYesPNeNot clear
Slide16[O I] l6300 Profiles
for T Tauri Stars Redshifted component not seen because of disk.
Slide17X-Ray Spectroscopy of Accretion Disks in AGNsMCG-6-30-15
Gravitational redshift plus Doppler shift
Slide18Do Jets Require an Accretion Disk?
Qualified Yes“Interacting winds”, “ion torus”, Pulsars, GRBs, need more work
Slide19Do Accretion Disks Require Jets or Outflows?
Are outflows/jets the main mechanism for transport/removal of angular momentum?Angular momentum carried by wind
Slide20Do Accretion Disks Require Jets or Outflows?
Angular momentum that needs to be removed from disk
For
r
A ~ 10r, only 1% of the accreted mass needs to be lost in wind.
Slide21Behavior of Disk Radius During Dwarf Nova Outburst
At outburst, matter diffuses inward. Angular momentum of that matter is transferred to outer parts of the disk.
Radius expands
Observationally:
Disks in U Gem, OY Car, HT Cas and Z Cha larger in outburst.U Gem
Slide22Behavior of Disk Radius During
Dwarf Nova OutburstTheory: disk instability
Slide23Do accretion disks require jets or outflows for angular momentum removal?
Probably not.More observations of rotation in jets and bipolar outflows are needed (velocity gradients).
Slide24Other Clues on JetsJet Origin
ObjectExample
V
jet
/VescapeYSOsHH30, 34Vj ~ 100-350km/sVesc ~ 500km/s~1AGNM87; radio sourcesΓ ≳ 3; Γ ≲ 10 ~1GRBsΓ ~ 100
~1XRBsSS 433;
Cyg X-3Vj ~ 0.6c~1XRTsGRO 1655-40GRS 1915+105V
j ≳ 0.9c~1
Pne
Fliers,
Ansae
V ~ 200km/s
~1
SSS
0513-69
V
j
~ 3800km/s
~1
Slide25Other Clues on JetsJets originate from the
center of the accretion disk!Models which work at all radii are probably not the “correct” ones, (e.g. self similar).
Slide26Black Hole Jets – x-ray transients
Two states: dissipation and disk luminosity, bulk flow and jet.
Slide27New Timescale
Timescale for jettj ~ td2R/H
1/f power spectrum below a break frequency.
Slide28Main Question:
Which ingredients play a major role in the acceleration and collimation?
Slide29Ingredients which may not
be absolutely necessary
YSOs
AGN
XRBsSSSGRBsCVsCentral object near break-up rotationNo?No, ????Relativistic central objectNo
YesYes
NoYesNo“Funnel”No (?)
No (?)No (?)
No
Yes (?)
No
L
≳
L
Edd
(Radiation pressure)
(wind can be driven)
No
No
No
Yes
?
No
Extensive hot atmosphere
(gas pressure)
Yes (?)
Yes
No
No
Yes (?)
No
Boundary layer
Yes (?)
No
?
Yes (?)
No
Yes (?)
Slide30What Does Work?
A reasonably ordered large-scale magnetic field threading the disk!
Slide31Magneto-Centrifugal Jet Acceleration and Collimation
Acceleration like a bead on a wire up to the Alfven surface. Acceleration optimal around inclination of 60°.
Slide32Collimation Outside Alfven Surface
Collimation by hoop stress?
BUT
Kink Instability
Slide33Poloidal CollimationNecessary Conditions
Rdisk/Robject = Significant number of decades Bz
largest at inner disk but
largest at
outer disk e.g. Bz ~ (r/Rin)-1Good collimation obtained forRAlfven ~ RdiskConsequencesMinimum opening angle of jetΘmin ~ (Rin/Rout)1/2
Slide34M87 VLBA at 43 GHz
Slide35M87
Slide36Long GRB: Collapse of Massive Star
Slide37Short GRB: Collision of Two Neutron Stars
Slide38Are There Additional Ingredients?Why are there radio-loud and radio-quiet AGN?
Why do CVs appear not to produce jets while SSS do?How can pulsars produce jets?
Slide39ConjectureThe production of powerful jets requires an additional heat/wind source.
Solutions to transsonic flow in disk corona: for strong B a potential difference exists even for i > 30 (Δφ ~ B4
)
.
Slide40Radio Loud vs. Radio Quiet AGN
Central engine
parameters:
Slide41Recent simulations: Magnetic “Tower”
Slide42Simulation results for
spinning black holeOutgoing velocity ~0.4-0.6c in funnel wall jetPoynting flux dominates within funnelBoth pressure and Lorentz forces important for acceleration
Existence of funnel jet depends on establishing radial funnel field
Jet luminosity increases with hole spin – Poynting flux jet is powered by the black hole
Slide43Simulations: dependence on black hole spin
a/M
η
EM
-0.900.0230.000.00030.500.00630.90
0.0460.93
0.0380.950.0720.99
0.21
Slide44Spins of Black Holes?R
ISCO, a*, determined on the basis of x-ray continuum data (even beyond thermal-dominant state).Study of plunging orbits important. Spin estimates based on stress-free inner boundary condition give upper limit on a*?
Source
M
(Mʘ)a*GRO J1655-406.3±0.27~0.74U 1543-479.4±1.0~0.8XTE J1550-5649.1±0.61~0.34A0620-00
6.61±0.25
~0.12GRS 1915+10514±4.4~0.975
Slide45Correlation between jet power and BH spin
Slide46Critical ObservationsDeterminations of the collimation scale
in all classes of objects.Detection and measurement of rotation and of toroidal magnetic fields in jets and bipolar outflows.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!Determination of black hole masses in AGN.Determination of black hole spins.Observations of collimated jets in pulsars.Afterglow light curves and breaks in GRBs.Differences between short and long burst in GRBs.