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A Jet-Emitting Disk model for the microquasar broad band emission

A Jet-Emitting Disk model for the microquasar broad band emission. G. Henri Coll. P.O Petrucci, J. Ferreira, C. Foellmi Laboratoire d ’Astrophysique de Grenoble, France. Accretion and ejection. X-ray binaries show strong spectral variability. Low-hard hot corona

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A Jet-Emitting Disk model for the microquasar broad band emission

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  1. A Jet-Emitting Disk model for the microquasar broad band emission G. Henri Coll. P.O Petrucci, J. Ferreira, C. Foellmi Laboratoire d ’Astrophysique de Grenoble, France The X-ray Universe 2008, Granada, May 27-30 2008

  2. Accretion and ejection X-ray binaries show strong spectral variability • Low-hard • hot corona • disk emission weak or absent • High soft • disk-dominated • non thermal power-law Grove et al ‘98 The X-ray Universe 2008, Granada, May 27-30 2008

  3. . At least two parameters : M and…… ? Hysteresis cycle Hardness-intensity plots show characteristic hysteresis cycles e.g. GX339-4 Belloni et al. ‘05 . The X-ray Universe 2008, Granada, May 27-30 2008

  4. « Jet-line » flaring events • Compact (optically thick) jets associated with low-hard states • Relativistic flares (optically thin) generally associated with luminous « Very High states » when crossing a « jet line » (Fender et al. ‘04) e.g. GRS 1915+105 Dhawan et al. 2000 (Mirabel & Rodriguez 1994) superluminal velocities The X-ray Universe 2008, Granada, May 27-30 2008

  5. Spectral transitions GRS 1915+105 . Flaring events associated with the disappearance of the disk emission and hardening spectra e.g. Mirabel et al., 1998 Correlations betwen X and radio (Corbel et al. 2003; Gallo et al. 2004… The X-ray Universe 2008, Granada, May 27-30 2008

  6. A Jet Emitting Disk model :general picture Flaring relativistic jets explained by pair creation events (~ AGNs) • Inner accretion disk emitting a Jet by a MHD centrifugal process Outer Standard accretion disk (SAD) Characteristic transition radius rj The X-ray Universe 2008, Granada, May 27-30 2008

  7. The MHD Jet Emitting Disk Baryonic jet can be emitted from the accretion disk through MHD mechanism (Blandford-Payne 1982, Ferreira et al., 1997, 2004) B field extracts angular momentum and power from the JED (Jet Emitting Disk) Powerful, but only mildly relativistic (0,5 - 0,9 c) The X-ray Universe 2008, Granada, May 27-30 2008

  8. Energetics Jets extract a fair part of the accretion energy Where Stable solutions can exist only close to equipartition If magnetization parameter Jet power -> underluminous disks can « apparently » disappear ~ ADAF but energy channelled in jets, not below the horizon The X-ray Universe 2008, Granada, May 27-30 2008

  9. JED Pmag/Ptot SAD 1 0.1 r rtr Magnetic transitions In the outer standard disc µ if r In the inner JED µ ~ Constant (adjusted by the MHD structure) ASSUMPTIONS (Standard Accretion Disc) (Jet Emitting Disc)  SAD  JED when µ ~ 1  JED  SAD when µ ~ 0.1 The X-ray Universe 2008, Granada, May 27-30 2008

  10. Hysteresis cycles Petrucci et al, MNRAS 2008 The X-ray Universe 2008, Granada, May 27-30 2008

  11. JED structure Thermal JED structure must be determined self-consistently Simple approximations * isothermal vertical structure * cooling processes : bremsstrahlung, synchrotron, comptonization. * heating process = part of accretion energy Non-linear dependance of heating on Balance solved numerically The X-ray Universe 2008, Granada, May 27-30 2008

  12. Multivalued solutions Compt. Qheat Qheat Synchr. Synchr. Bremsstr. Bremsstr. Cold solution : standard disk-like Hot solution : corona-like The X-ray Universe 2008, Granada, May 27-30 2008

  13. Radiative transitions The X-ray Universe 2008, Granada, May 27-30 2008

  14. Spectral Energy Distributions Example of SED Depends on radial structure, complicated with multivalued solutions and variability… still in progress…. The X-ray Universe 2008, Granada, May 27-30 2008

  15. Ejection of relativistic components 2-flow model for AGNs In situ generation of pair plasma in the inner MHD funnel (H.& Pelletier 91, Marcowith et al. ‘95) Produced through gamma-ray emission • Injection of some relativistic particles • X-ray and gamma-ray emission by IC and/or SSC • g-g annihilation forms new pairs • Continuous reacceleration by MHD turbulence necessary for a pair runaway to develop. • Limited by the free energy available: saturation must occur at some point. • Intermittent production possible and even probable ! The X-ray Universe 2008, Granada, May 27-30 2008

  16. Time dependant flares See Boutelier’s poster (#G4) for the PKS2155-304 case TeV flux Pair production X-ray/optical The X-ray Universe 2008, Granada, May 27-30 2008

  17. rtr rin Hard X    UV/Soft X  Generation of low frequency QPO • Density n0(r) • Temperature T0(r) + n(r,t) + T(r,t) The X-ray Universe 2008, Granada, May 27-30 2008

  18. rtr rin     resonances  cs/rtr Monte Carlo Simulations SED White noise PDS • Vertical optical t0 = 1.4 • Temperature T0=100 keV • rtr=50 rg, cs=(kT0/mp)0.5~0.01c RMS Cabanac PhD thesis The X-ray Universe 2008, Granada, May 27-30 2008 Energy (keV)

  19. Conclusions • A magnetically dominated, inner jet emitting disk can provide a good framework to understand • Spectral changes • Correlation X-radio • Variability, QPO • Complicated interplay between accretion rate, magnetic transitions , radiative instabilities .. (but reality IS complex ! ) • Work in progress to compare with detailed spectra and variability. The X-ray Universe 2008, Granada, May 27-30 2008

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