The magnetic nature of disk accretion onto black holes


Although disk accretion onto compact objects—white dwarfs, neutron stars and black holes—is central to much of high-energy astrophysics, the mechanisms that enable this process have remained observationally difficult to determine. Accretion disks must transfer angular momentum in order for matter to travel radially inward onto the compact object1. Internal viscosity from magnetic processes1,2,3,4 and disk winds5 can both in principle transfer angular momentum, but hitherto we lacked evidence that either occurs. Here we report that an X-ray-absorbing wind discovered in an observation of the stellar-mass black hole binary GRO J1655 - 40 (ref. 6) must be powered by a magnetic process that can also drive accretion through the disk. Detailed spectral analysis and modelling of the wind shows that it can only be powered by pressure generated by magnetic viscosity internal to the disk or magnetocentrifugal forces. This result demonstrates that disk accretion onto black holes is a fundamentally magnetic process.

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Figure 1: A small part of the disk wind spectrum observed in GRO J1655 - 40 with Chandra.
Figure 2: Comparison to the data of the best model for the disk wind in GRO J1655 - 40.


  1. 1

    Shakura, N. I. & Sunyaev, R. A. Black holes in binary systems. Observational appearance. Astron. Astrophys. 24, 337–355 (1973)

    ADS  Google Scholar 

  2. 2

    Balbus, S. A. & Hawley, J. F. A powerful local shear instability in weakly magnetized disks. Astrophys. J. 376, 214–233 (1991)

    ADS  Article  Google Scholar 

  3. 3

    Hawley, J. F., Gammie, C. F. & Balbus, S. A. Local three-dimensional magnetohydrodynamic solutions of accretion disks. Astrophys. J. 440, 742–763 (1995)

    ADS  Article  Google Scholar 

  4. 4

    Balbus, S. A. & Hawley, J. F. Instability, turbulence, and enhanced transport in accretion disks. Rev. Mod. Phys. 70, 1–53 (1998)

    ADS  Article  Google Scholar 

  5. 5

    Blandford, R. D. & Payne, D. G. Hydromagnetic flows from accretion disks and the production of radio jets. Mon. Not. R. Astron. Soc. 199, 883–903 (1982)

    ADS  Article  Google Scholar 

  6. 6

    Orosz, J. & Bailyn, C. D. Optical observations of GRO J1655 - 40 in quiescence. I. A precise mass for the black hole primary. Astrophys. J. 477, 876–896 (1997)

    ADS  Article  Google Scholar 

  7. 7

    Hjellming, R. M. & Rupen, M. P. Episodic ejection of relativistic jets by the X-ray transient GRO J1655 - 40. Nature 375, 464–468 (1995)

    ADS  CAS  Article  Google Scholar 

  8. 8

    Dickey, J. M. & Lockman, F. J. H I in the Galaxy. Annu. Rev. Astron. Astrophys. 28, 215–261 (1990)

    ADS  CAS  Article  Google Scholar 

  9. 9

    Verner, D. A., Verner, E. M. & Ferland, G. J. Atomic data for permitted resonance lines of atoms and ions from H to Si, and S, Ar, Ca, and Fe. Atom. Data Nucl. Data Tables 64, 11–180 (1996)

    ADS  Article  Google Scholar 

  10. 10

    The NIST Atomic Spectra Database, Standard Reference Database 78. (2005).

  11. 11

    Nahar, S. & Pradhan, A. K. Atomic data from the Iron Project. XXXV. Relativistic fine structure oscillator strengths for Fe XXIV and Fe XXV. Astron. Astrophys. Suppl. 135, 347–357 (1999)

    ADS  CAS  Article  Google Scholar 

  12. 12

    Raymond, J. A model of an X-ray-illuminated accretion disk and corona. Astrophys. J. 412, 267–277 (1993)

    ADS  CAS  Article  Google Scholar 

  13. 13

    Miller, J. M. et al. Chandra/HETGS spectroscopy of the Galactic black hole GX 399 - 4: A relativistic iron emission line and evidence for a Seyfert-like warm absorber. Astrophys. J. 601, 450–465 (2004)

    ADS  CAS  Article  Google Scholar 

  14. 14

    Colgan, J., Pindzola, M. S. & Badnell, N. R. Dielectronic recombination data for dynamic finite-density plasmas. V: the lithium isoelectronic sequence. Astron. Astrophys. 417, 1183–1188 (2004)

    ADS  CAS  Article  Google Scholar 

  15. 15

    Spitzer, L. Physical Processes in the Interstellar Medium (Wiley, New York, 1978)

    Google Scholar 

  16. 16

    Grevesse, N. & Sauval, A. J. in Solar Composition and its Evolution–from Core to Corona (eds Frölich, C., Huber, M. C. E., Solanski, S. K. & von Steiger, R.) 161–174 (Kluwer, Dordrecht, 1998)

    Google Scholar 

  17. 17

    Vrtilek, S. et al. Observations of Cygnus X-2 with IUE—Ultraviolet results from a multi-wavelength campaign. Astron. Astrophys. 234, 162–173 (1990)

    ADS  Google Scholar 

  18. 18

    Begelman, M. C., McKee, C. F. & Shields, G. A. Compton heated winds and coronae above accretion disks. II Dynamics. Astrophys. J. 271, 70–89 (1983)

    ADS  CAS  Article  Google Scholar 

  19. 19

    Chelouche, D. & Netzer, H. Dynamical and spectral modeling of the ionized gas and nuclear environment in NGC 3783. Astrophys. J. 625, 95–107 (2005)

    ADS  CAS  Article  Google Scholar 

  20. 20

    Proga, D., Stone, J. M. & Kallman, T. R. Dynamics of line-driven winds in active galactic nuclei. Astrophys. J. 543, 686–696 (2000)

    ADS  Article  Google Scholar 

  21. 21

    Miller, K. A. & Stone, J. M. The formation and structure of a strongly magnetized corona above a weakly magnetized accretion disk. Astrophys. J. 534, 398–419 (2000)

    ADS  Article  Google Scholar 

  22. 22

    Proga, D. Numerical simulations of mass outflows driven from accretion disks by radiation and magnetic forces. Astrophys. J. 585, 406–417 (2003)

    ADS  Article  Google Scholar 

  23. 23

    Spruit, H. C. in Physical Processes in Binary Stars (eds Wijers, R. A. M. J., Davies, M. B. & Tout, C. A.) 249–286 (NATO ASI Ser., Kluwer, Dordrecht, 1996)

    Google Scholar 

  24. 24

    Calvet, N., Hartmann, L. & Kenyon, S. J. Mass loss from pre-main-sequence accretion disks. I—The accelerating wind of FU Orionis. Astrophys. J. 402, 623–634 (1993)

    ADS  Article  Google Scholar 

  25. 25

    Schulz, N. S. & Brandt, W. N. Variability of the X-ray P Cygni line profiles from Cicinus X-1 near zero phase. Astrophys. J. 572, 972–983 (2002)

    Article  Google Scholar 

  26. 26

    Mauche, C. W. & Raymond, J. C. Extreme Ultraviolet Explorer observations of OY Carinae in superoutburst. Astrophys. J. 541, 924–936 (2000)

    ADS  Article  Google Scholar 

  27. 27

    Konigl, A. & Kartje, J. F. Disk-driven hydromagnetic winds as a key ingredient of active galactic nuclei unification schemes. Astrophys. J. 434, 446–467 (1994)

    ADS  Article  Google Scholar 

  28. 28

    Everett, J. E. Radiative transfer and acceleration in magnetocentrifugal winds. Astrophys. J. 631, 689–706 (2005)

    ADS  CAS  Article  Google Scholar 

  29. 29

    Houck, J. C. & Denicola, L. A. ISIS: An interactive spectral interpretation system for high resolution X-ray spectroscopy. Astron. Soc. Pacif. Conf. Proc. 216, 591–594 (2000)

    ADS  Google Scholar 

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We acknowledge conversations with N. Calvet, L. Hartmann, D. Proga and M. Rupen. We are indebted to A. Prestwich, H. Tananbaum and the Chandra staff for help in making this observation possible. We thank B. Lauritsen for editorial insights. This work was supported by NASA through the Chandra guest observer programme (J.M.M.). Author Contributions J.M.M. analysed the Chandra data and wrote most of the paper. J.R. developed the photoionization model. J.M.M., J.R., A.F. and C.R. developed the interpretation of the data. D.S., J.H., M.K. and R.W. contributed insights on X-ray binaries and/or made supporting observations with other instruments. All others discussed the work at length, and contributed to the manuscript.

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Correspondence to Jon M. Miller.

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Miller, J., Raymond, J., Fabian, A. et al. The magnetic nature of disk accretion onto black holes. Nature 441, 953–955 (2006).

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