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8 - Computing black-hole accretion

Published online by Cambridge University Press:  05 January 2014

By
John F. Hawley
Edited by
Ignacio González Martínez-País ,
Tariq Shahbaz  and
Jorge Casares Velázquez
John F. Hawley
Affiliation:
University of Virginia
Ignacio González Martínez-País
Affiliation:
Instituto de Astrofísica de Canarias, Tenerife
Tariq Shahbaz
Affiliation:
Instituto de Astrofísica de Canarias, Tenerife
Jorge Casares Velázquez
Affiliation:
Instituto de Astrofísica de Canarias, Tenerife
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Summary

8.1 Introduction

Astronomers have a remarkably successful theory for stars and stellar evolution. This success is due in part to the simplicity of spherical symmetry and steady-state equilibrium. Stars can be modeled using a series of time-independent equations that depend on only one spatial coordinate, namely the radius of the star. But the universe is a much more dynamic and active place than is implied by the stars alone. Some of the most energetic photons that astronomers observe originate not within stars but in orbiting disks of gas. This realization has brought the study of accretion disks to the forefront of high-energy astrophysics.

The idea of an orbiting disk of gas in a context other than that of a nascent solar system or spiral galaxy can be traced at least as far back as the work of astronomer Gerard Kuiper on mass transfer in close binary stellar systems. He noted that in such systems, gas can flow through a stream from one star to the other. Kuiper realized that the gas would possess sufficient angular momentum that it must go into orbit around the attracting star, forming a ring.

In 1955, John Crawford and Robert Kraft published a paper (Crawford and Kraft, 1956) that proposed an orbiting ring model for AE Aquarii, a short-period binary star system that showed significant episodic variability. The masses of the stars and the sizes of their orbits were such that mass transfer from one star to the other was likely.

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Accretion Processes in Astrophysics , pp. 253 - 290
Publisher: Cambridge University Press
Print publication year: 2014

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References

Abramowicz, M., Brandenburg, A., and Lasota, J.-P. 1996. The dependence of the viscosity in accretion discs on the shear/vorticity ratio. MNRAS, 281, L21–L24.Google Scholar
Agol, E., and Krolik, J. H. 2000. Magnetic stress at the marginally stable orbit: altered disk structure, radiation, and black hole spin evolution. ApJ, 528(Jan.), 161–170.Google Scholar
Anninos, P., Fragile, P. C., and Salmonson, J. D. 2005. Cosmos++: relativistic magnetohydro-dynamics on unstructured grids with local adaptive refinement. ApJ, 635(Dec.), 723–740.Google Scholar
Anton, L., Zanotti, O., Miralles, J. A., Marti, J. M., Ibafiez, J. M., Font, J. A., and Pons, J. A. 2006. Numerical 3+1 general relativistic magnetohydrodynamics: a local characteristic approach. ApJ, 637(Jan.), 296–312.Google Scholar
Balbus, S. A. 1995. General local stability criteria for stratified, weakly magnetized rotating systems. ApJ, 453, 380–383.Google Scholar
Balbus, S. A. 2003. Enhanced angular Momentum transport in accretion disks. Ann. Rev. Astron. Astrophys., 41, 555–597.Google Scholar
Balbus, S. A., and Hawley, J. F. 1992a. A powerful local shear instability in weakly magnetized disks. IV. Nonaxisymmetric perturbations. ApJ, 400, 610–621.Google Scholar
Balbus, S. A., and Hawley, J. F. 1992b. Is the Oort A-value a universal growth rate limit for accretion disk shear instabilities?ApJ, 392, 662–666.Google Scholar
Balbus, S. A., and Hawley, J. F. 1998. Instability, turbulence, and enhanced transport in accretion disks. Reviews of Modern Physics, 70, 1–53.Google Scholar
Balbus, S. A., and Henri, P. 2008. On the magnetic Prandtl number behavior of accretion disks. ApJ, 674(Feb.), 408–414.Google Scholar
Balbus, S. A., and Papaloizou, J. C. B. 1999. On the dynamical foundations of alpha disks. ApJ, 521, 650–658.Google Scholar
Balbus, S. A., Hawley, J. F., and Stone, J. M. 1996. Nonlinear stability, hydrodynamical turbulence, and transport in disks. ApJ, 467, 76–86.Google Scholar
Bardeen, J. M., and Petterson, J. A. 1975. The Lense-Thirring effect and accretion disks around Kerr black holes. ApJ, 195(Jan.), L65–L67.Google Scholar
Beckwith, K., Hawley, J. F., and Krolik, J. H. 2008a. The influence of magnetic field geometry on the evolution of black hole accretion flows: similar disks, drastically different jets. ApJ, 678(May), 1180–1199.Google Scholar
Beckwith, K., Hawley, J. F., and Krolik, J. H. 2008b. Where is the radiation edge in magnetized black-hole accretion discs?MNRAS, 390(Oct.), 21–38.Google Scholar
Beckwith, K., Hawley, J. F., and Krolik, J. H. 2009. Transport of large scale poloidal flux in black-hole accretion. ApJ, 707, 428–445.Google Scholar
Blackman, E. G., Penna, R. F., and Varniere, P. 2008. Empirical relation between angular momentum transport and thermal-to-magnetic pressure ratio in shearing box simulations. New Astronomy, 13(May), 244–251.Google Scholar
Blaes, O. M., and Balbus, S. A. 1994. Local shear instabilities in weakly magnetized disks. ApJ, 421, 163–177.Google Scholar
Blandford, R. D., and Payne, D. G. 1982. Hydromagnetic flows from accretion discs and the production of radio jets. MNRAS, 199(June), 883–903.Google Scholar
Blandford, R. D., and Znajek, R. L. 1977. Electromagnetic extraction of energy from Kerr black holes. MNRAS, 179(May), 433–456.Google Scholar
Brackbill, J. U., and Barnes, D. C. 1980. The effect of nonzero product of magnetic gradient and B on the numerical solution of the magnetohydrodynamic equations. J. Comp. Phys., 35, 426–430.Google Scholar
Brandenburg, A., Nordlund, A., Stein, R. F., and Torkelsson, U. 1995. Dynamo-generated turbulence and large-scale magnetic fields in a Keplerian shear flow. ApJ, 446(June), 741–754.Google Scholar
Colella, P. 1990. Multidimensional upwind methods for hyperbolic conservation laws. J. Comp. Phys., 87(Mar.), 171–200.Google Scholar
Colella, P., and Woodward, P. R. 1984. The piecewise parabolic method (PPM) for gas-dynamical simulations. J. Comp. Phys., 54, 174–201.Google Scholar
Crawford, J. A., and Kraft, R. P. 1956. An intrepretation of AE Aquarii. ApJ, 123(Jan.), 44–53.Google Scholar
Davis, S. W., Stone, J. M., and Pessah, M. E. 2010. Sustained magnetorotational turbulence in local simulations of stratified disks with zero net magnetic flux. ApJ, 713(Apr.), 52–65.Google Scholar
De Villiers, J., Hawley, J. F., Krolik, J. H., and Hirose, S. 2005. Magnetically driven accretion in the Kerr metric. III. Unbound outflows. ApJ, 620(Feb.), 878–888.Google Scholar
De Villiers, J.-P., and Hawley, J. F. 2003. A numerical method for general relativistic magneto-hydrodynamics. ApJ, 589(May), 458–480.Google Scholar
Done, C., and Davis, S. W. 2008. Angular momentum transport in accretion disks and its implications for spin estimates in black hole binaries. ApJ, 683(Aug.), 389–399.Google Scholar
Duez, M. D., Liu, Y. T., Shapiro, S. L., and Stephens, B. C. 2005. Relativistic magnetohy-drodynamics in dynamical spacetimes: Numerical methods and tests. Phys. Rev. D, 72(2), 024028+.Google Scholar
Evans, C. R., and Hawley, J. F. 1988. Simulation of magnetohydrodynamic flows: a constrained transport method. ApJ, 332, 659–677.Google Scholar
Fleming, T. P., Stone, J. M., and Hawley, J. F. 2000. The effect of resistivity on the nonlinear stage of the magnetorotational instability in accretion disks. ApJ, 530(Feb.), 464–477.Google Scholar
Fragile, P. C. 2009. Effective inner radius of tilted black-hole accretion disks. ApJ, 706(Dec.), L246–L250.Google Scholar
Fragile, P. C., and Blaes, O. M. 2008. Epicyclic motions and standing shocks in numerically simulated tilted black-hole accretion disks. ApJ, 687(Nov.), 757–766.Google Scholar
Fragile, P. C., and Meier, D. L. 2009. General relativistic magnetohydrodynamic simulations of the hard state as a magnetically dominated accretion flow. ApJ, 693(Mar.), 771–783.Google Scholar
Fragile, P. C., Blaes, O. M., Anninos, P., and Salmonson, J. D. 2007. Global general relativistic magnetohydrodynamic simulation of a tilted black-hole accretion disk. ApJ, 668(Oct.), 417–429.Google Scholar
Fragile, P. C., Lindner, C. C., Anninos, P., and Salmonson, J. D. 2009. Application of the cubed-sphere grid to tilted black-hole accretion disks. ApJ, 691(Jan.), 482–494.Google Scholar
Fromang, S., and Papaloizou, J. 2007. MHD simulations of the magnetorotational instability in a shearing box with zero net flux. I. The issue of convergence. A&A, 476(Dec.), 1113–1122.Google Scholar
Fromang, S., Papaloizou, J., Lesur, G., and Heinemann, T. 2007. MHD simulations of the magnetorotational instability in a shearing box with zero net flux. II. The effect of transport coefficients. A&A, 476(Dec.), 1123–1132.Google Scholar
Gammie, C. F. 1999. Efficiency of magnetized thin accretion disks in the Kerr metric. ApJ, 522(September), L57–L60.Google Scholar
Gammie, C. F., and Balbus, S. A. 1994. Quasi-global linear analysis of a magnetized disc. MNRAS, 270(Sept.), 138–152.Google Scholar
Gammie, C. F., McKinney, J. C., and Toth, G. 2003. HARM: a numerical scheme for general relativistic magnetohydrodynamics. ApJ, 589(May), 444–457.Google Scholar
Gammie, C. F., Shapiro, S. L., and McKinney, J. C. 2004. Black hole spin evolution. ApJ, 602(Feb.), 312–319.Google Scholar
Goodman, J., and Xu, G. 1994. Parasitic instabilities in magnetized, differentially rotating disks. ApJ, 432(Sept.), 213–223.Google Scholar
Guan, X., and Gammie, C. F. 2008. Axisymmetric shearing box models of magnetized disks. ApJS, 174(Jan.), 145–157.Google Scholar
Hawley, J. F., and Balbus, S. A. 1992. A powerful local shear instability in weakly magnetized disks. III – Long-term evolution in a shearing sheet. ApJ, 400(Dec.), 595–609.Google Scholar
Hawley, J. F., and Krolik, J. H. 2001. Global MHD simulation of the inner accretion disk in a pseudo-Newtonian potential. ApJ, 548(Feb.), 348–367.Google Scholar
Hawley, J. F., and Krolik, J. H. 2002. High-resolution simulations of the plunging region in a pseudo-Newtonian potential: dependence on numerical resolution and field topology. ApJ, 566(Feb.), 164–180.Google Scholar
Hawley, J. F., and Krolik, J. H. 2006. Magnetically driven jets in the Kerr metric. ApJ, 641(Apr.), 103–116.Google Scholar
Hawley, J. F., and Stone, J. M. 1995. MOCCT: a numerical technique for astrophysical MHD. Computer Physics Communications, 89(Aug.), 127–148.Google Scholar
Hawley, J. F., Balbus, S. A., and Winters, W. F. 1999. Local hydrodynamic stability of accretion disks. ApJ, 518(June), 394–404.Google Scholar
Hawley, J. F., Gammie, C. F., and Balbus, S. A. 1995. Local three-dimensional magnetohydro-dynamic simulations of accretion disks. ApJ, 440(Feb.), 742–763.Google Scholar
Hawley, J. F., Gammie, C. F., and Balbus, S. A. 1996. Local three-dimensional simulations of an accretion disk hydromagnetic dynamo. ApJ, 464(June), 690–703.Google Scholar
Hirose, S., Krolik, J. H., and Blaes, O. 2009. Radiation-dominated disks are thermally stable. ApJ, 691 (Jan.), 16–31.Google Scholar
Hirose, S., Krolik, J. H., and Stone, J. M. 2006. Vertical structure of gas pressure-dominated accretion disks with local dissipation ofturbulence and radiative transport. ApJ, 640(Apr.), 901–917.Google Scholar
Jin, L. 1996. Damping of the shear instability in magnetized disks by Ohmic diffusion. ApJ, 457, 798–804.Google Scholar
Koide, S., Shibata, K., Kudoh, T., and Meier, D. L. 2001. Numerical method for general rela-tivistic magnetohydrodynamics in Kerr space-time. Journal of Korean Astronomical Society, 34(Dec.), 215–224.Google Scholar
Komissarov, S. S. 2004. General relativistic magnetohydrodynamic simulations of monopole magnetospheres of black holes. MNRAS, 350(June), 1431–1436.Google Scholar
Krolik, J. H. 1999. Magnetized accretion inside the marginally stable orbit around a black hole. ApJ, 515(April), L73–L76.Google Scholar
Krolik, J. H., Hawley, J. F., and Hirose, S. 2005. Magnetically driven accretion flows in the Kerr metric. IV. Dynamical properties of the inner disk. ApJ, 622(Apr.), 1008–1023.Google Scholar
Latter, H. N., Lesaffre, P., and Balbus, S. A. 2009. MRI channel flows and their parasites. MNRAS, 394(Apr.), 715–729.Google Scholar
Lesur, G., and Longaretti, P.-Y. 2007. Impact of dimensionless numbers on the efficiency of magnetorotational instability induced turbulent transport. MNRAS, 378(July), 1471–1480.Google Scholar
Lightman, A. P., and Eardley, D. M. 1974. Black holes in binary systems: instability of disk accretion. ApJ, 187(Jan.), L1–L3.Google Scholar
Livio, M. 2000. Astrophysical jets. Pages 275–297 of: Holt, S. S., and Zhang, W. W. (eds.), American Institute of Physics Conference Series. American Institute of Physics Conference Series, vol. 522.
Lynden-Bell, D. 1969. Galactic nuclei as collapsed old quasars. Nature, 223(Aug.), 690–694.Google Scholar
Machida, M., and Matsumoto, R. 2003. Global three-dimensional magnetohydrodynamic simulations of black hole accretion disks: X-ray flares in the plunging region. ApJ, 585(Mar.), 429–442.Google Scholar
McKinney, J. C. 2005. Total and jet Blandford-Znajek power in the presence of an accretion disk. ApJ, 630(Sept.), L5–L8.Google Scholar
McKinney, J. C. 2006. General relativistic magnetohydrodynamic simulations of the jet formation and large-scale propagation from black-hole accretion systems. MNRAS, 368(June), 1561–1582.Google Scholar
McKinney, J. C., and Blandford, R. D. 2009. Stability of relativistic jets from rotating, accreting black holes via fully three-dimensional magnetohydrodynamic simulations. MNRAS, 394(Mar.), L126–L130.Google Scholar
McKinney, J. C., and Gammie, C. F. 2004. A measurement of the electromagnetic luminosity of a Kerr black hole. ApJ, 611(August), 977–995.Google Scholar
Meier, D. L. 2005. Magnetically dominated accretion flows (MDAFS) and jet production in the lowhard state. Astrophys. Space Sci., 300(Nov.), 55–65.Google Scholar
Mignone, A., Bodo, G., Massaglia, S., Matsakos, T., Tesileanu, O., Zanni, C., and Ferrari, A. 2007. PLUTO: a numerical code for computational astrophysics. ApJS, 170(May), 228–242.Google Scholar
Miller, K. A., and Stone, J. M. 2000. The formation and structure of a strongly magnetized corona above a weakly magnetized accretion disk. ApJ, 534(May), 398–419.Google Scholar
Moscibrodzka, M., Gammie, C. F., Dolence, J. C., Shiokawa, H., and Leung, P. K. 2009. Radiative models of SGR A* from GRMHD simulations. ApJ, 706(Nov.), 497–507.Google Scholar
Noble, S. C., and Krolik, J. H. 2009. GRMHD prediction of coronal variability in accreting black holes. ApJ, 703(Sept.), 964–975.Google Scholar
Noble, S. C., Gammie, C. F., McKinney, J. C., and Del Zanna, L. 2006. Primitive variable solvers for conservative general relativistic magnetohydrodynamics. ApJ, 641 (Apr.), 626–637.Google Scholar
Noble, S. C., Krolik, J. H., and Hawley, J. F. 2009. Direct calculation of the radiative efficiency of an accretion disk around a black hole. ApJ, 692(Feb.), 411–421.Google Scholar
Noble, S. C., Krolik, J. H., and Hawley, J. F. 2010. Dependence of inner accretion disk stress on parameters: the Schwarzschild case. ApJ, 711(Feb.), 959–973.Google Scholar
Novikov, I. D., and Thorne, K. S. 1973. Astrophysics of black holes. Pages 343–450 of: De Witt, C. (ed.), Black Holes (Les Astres Occlus). Gordon and Breach.
Pessah, M. E., Chan, C.-K., and Psaltis, D. 2006. The signature of the magnetorotational instability in the Reynolds and Maxwell stress tensors in accretion discs. MNRAS, 372(Oct.), 183–190.Google Scholar
Pessah, M. E., Chan, C.-k., and Psaltis, D. 2007. Angular momentum transport in accretion disks: scaling laws in MRI-driven turbulence. ApJ, 668(Oct.), L51–L54.Google Scholar
Pudritz, R. E., Ouyed, R., Fendt, C., and Brandenburg, A. 2007. Disk winds, jets, and outflows: theoretical and computational foundations. Pages 277–294 of: Reipurth, B., Jewitt, D., and Keil, K. (eds.), Protostars and Planets V. University of Arizona Press, Tucson.
Reynolds, C. S., and Armitage, P. J. 2001. A variable efficiency for thin-disk black-hole accretion. ApJ, 561(Nov.), L81–L84.Google Scholar
Reynolds, C. S., and Fabian, A. C. 2008. Broad iron-Ka emission lines as a diagnostic of black hole spin. ApJ, 675(Mar.), 1048–1056.Google Scholar
Sano, T. 2007. The evolution of channel flows in MHD turbulence driven by magnetorotational instability. Astrophys. Space Sci., 307(Jan.), 191–195.Google Scholar
Sano, T., and Inutsuka, S.-I. 2001. Saturation and thermalization of the magnetorotational instability: recurrent channel flows and reconnections. ApJ, 561 (Nov.), L179–L182.Google Scholar
Sano, T., and Stone, J. M. 2002. The effect of the Hall term on the nonlinear evolution of the magnetorotational instability. II. Saturation level and critical magnetic Reynolds number. ApJ, 577(Sept.), 534–553.Google Scholar
Sano, T., Inutsuka, S.-I., and Miyama, S. M. 1998. A saturation mechanism of magnetorotational instability due to ohmic dissipation. ApJ, 506(Oct.), L57–L60.Google Scholar
Sano, T., Inutsuka, S.-I., Turner, N. J., and Stone, J. M. 2004. Angular momentum transport by magnetohydrodynamic turbulence in accretion disks: gas pressure dependence of the saturation level of the magnetorotational instability. ApJ, 605(Apr.), 321–339.Google Scholar
Schnittman, J. D., Krolik, J. H., and Hawley, J. F. 2006. Light curves from an MHD simulation of a black-hole accretion disk. ApJ, 651(Nov.), 1031–1048.Google Scholar
Shafee, R., McKinney, J. C., Narayan, R., Tchekhovskoy, A., Gammie, C. F., and McClintock, J. E. 2008. Three-dimensional simulations of magnetized thin accretion disks around black holes: stress in the plunging region. ApJ, 687(Nov.), L25–L28.Google Scholar
Shakura, N. I., and Sunyaev, R. A. 1973. Black holes in binary systems. Observational appearance. A&A, 24, 337–355.Google Scholar
Shakura, N. I., and Sunyaev, R. A. 1976. A theory of the instability of disk accretion on to black holes and the variability of binary X-ray sources, galactic nuclei and quasars. MNRAS, 175(June), 613–632.Google Scholar
Shi, J.-M., Krolik, J. H., and Hirose, S. 2010. What is the numerically converged amplitude of MHD turbulence in stratified shearing boxes?ApJ, 708(Jan.), 1716–1727.Google Scholar
Simon, J. B., and Hawley, J. F. 2009. Viscous and resistive effects on the magnetorotational instability with a net toroidal field. ApJ, 707(Dec.), 833–843.Google Scholar
Simon, J. B., Hawley, J. F., and Beckwith, K. 2009. Simulations of magnetorotational turbulence with a higher-order Godunov scheme. ApJ, 690(Jan.), 974–997.Google Scholar
Stone, J. M., and Balbus, S. A. 1996. Angular momentum transport in accretion disks via convection. ApJ, 464(June), 346–372.Google Scholar
Stone, J. M., and Norman, M. L. 1992a. ZEUS-2D: A radiation magnetohydrodynamics code for astrophysical flows in two space dimensions. I – The hydrodynamic algorithms and tests. ApJS, 80(June), 753–790.Google Scholar
Stone, J. M., and Norman, M. L. 1992b. ZEUS-2D: a radiation magnetohydrodynamics code for astrophysical flows in two space dimensions. II. The magnetohydrodynamic algorithms and tests. ApJS, 80(June), 791–818.Google Scholar
Stone, J. M., Hawley, J. F., Gammie, C. F., and Balbus, S. A. 1996. Three-dimensional mag-netohydrodynamical simulations of vertically stratified accretion disks. ApJ, 463(June), 656–673.Google Scholar
Stone, J. M., Gardiner, T. A., Teuben, P., Hawley, J. F., and Simon, J. B. 2008. Athena: a new code for astrophysical MHD. ApJS, 178(Sept.), 137–177.Google Scholar
Tassoul, J.-L. 1978. Theory ofRotating Stars. Princeton, NJ, Princeton University Press.
Thorne, K. S. 1974. Disk-accretion onto a black hole. II. Evolution of the hole. ApJ, 191(July), 507–520.Google Scholar
Thorne, K. S., Price, R. H., and MacDonald, D. A. 1986, Black holes: The membrane paradigm. New Haven, CT, Yale University Press, 380, p.
Tout, C. A., and Pringle, J. E. 1996. Can a disc dynamo generate large-scale magnetic fields?MNRAS, 281(July), 219–225.Google Scholar
Turner, N. J. 2004. On the vertical structure of radiation-dominated accretion disks. ApJ, 605(Apr.), L45–L48.Google Scholar
van Ballegooijen, A. A. 1989. Magnetic fields in the accretion disks of cataclysmic variables. Pages 99–106 of: Belvedere, G. (ed.), Accretion Disks and Magnetic Fields in Astrophysics. Astrophysics and Space Science Library, vol. 156.
Wardle, M. 1999. The Balbus-Hawley instability in weakly ionized discs. MNRAS, 307, 849–856.Google Scholar
Wilson, J. R. 1975. Some magnetic effects in stellar collapse and accretion. New York Academy of Sciences Annals, 262(Oct.), 123–132.Google Scholar
Ziegler, U., and Rudiger, G. 2001. Shear rate dependence and the effect of resistivity in magneto-rotationally unstable, stratified disks. A&A, 378(Nov.), 668–678.Google Scholar

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