An Eccentric Circumbinary Accretion Disk and the Detection of Binary Massive Black Holes

We present a two-dimensional grid-based hydrodynamic simulation of a thin, viscous, locally isothermal corotating disk orbiting an equal-mass Newtonian binary point mass on a fixed circular orbit. We study the structure of the disk after multiple viscous times. The binary maintains a central hole in the viscously relaxed disk with radius equal to about twice the binary semimajor axis. Disk surface density within the hole is reduced by orders of magnitude relative to the density in the disk bulk. The inner truncation of the disk resembles the clearing of a gap in a protoplanetary disk. An initially circular disk becomes elliptical and then eccentric. Disturbances in the disk contain a component that is stationary in the rotating frame in which the binary is at rest; this component is a two-armed spiral density wave. We measure the distribution of the binary torque in the disk and find that the strongest positive torque is exerted inside the central low-density hole. We make connection with the linear theory of disk forcing at outer Lindblad resonances (OLRs) and find that the measured torque density distribution is consistent with forcing at the 3:2 (m = 2) OLR, well within the central hole. We also measure the time dependence of the rate at which gas accretes across the hole and find quasi-periodic structure. We discuss implications for variability and detection of active galactic nuclei containing a binary massive black hole.

[1]  M. Eracleous,et al.  Modeling of Emission Signatures of Massive Black Hole Binaries. I. Methods , 2007, 0708.0414.

[2]  S. Lubow,et al.  Evolution of Giant Planets in Eccentric Disks , 2006, astro-ph/0608355.

[3]  W. Keel,et al.  The 2005 November Outburst in OJ 287 and the Binary Black Hole Model , 2006 .

[4]  National Radio Astronomy Observatory,et al.  A Compact Supermassive Binary Black Hole System , 2006, astro-ph/0604042.

[5]  Gennaro D'Angelo,et al.  Gas Flow across Gaps in Protoplanetary Disks , 2005, astro-ph/0512292.

[6]  Z. Frei,et al.  Finding the Electromagnetic Counterparts of Cosmological Standard Sirens , 2005, astro-ph/0505394.

[7]  W. Kley,et al.  Disk eccentricity and embedded planets , 2005, astro-ph/0510393.

[8]  P. Armitage,et al.  Eccentricity of Supermassive Black Hole Binaries Coalescing from Gas-rich Mergers , 2005, astro-ph/0508493.

[9]  Daniel E. Holz,et al.  Using Gravitational-Wave Standard Sirens , 2005, astro-ph/0504616.

[10]  L. Sparke,et al.  Circumstellar and circumbinary discs in eccentric stellar binaries , 2005, astro-ph/0501244.

[11]  M. Milosavljevic,et al.  Massive Black Hole Binary Evolution , 2004, astro-ph/0410364.

[12]  E. Phinney,et al.  The Afterglow of Massive Black Hole Coalescence , 2004, astro-ph/0410343.

[13]  W. Kley,et al.  Evolution of irradiated circumbinary disks , 2004, astro-ph/0405053.

[14]  D. Mardones,et al.  The Role of Gas in the Merging of Massive Black Holes in Galactic Nuclei. II. Black Hole Merging in a Nuclear Gas Disk , 2003, astro-ph/0406304.

[15]  J. Centrella.  THE ASTROPHYSICS OF GRAVITATIONAL WAVE SOURCES , 2003 .

[16]  Jeremy Goodman,et al.  Self-gravity and quasi-stellar object discs , 2003 .

[17]  R. Sari,et al.  A Generalization of the Lagrangian Points: Studies of Resonance for Highly Eccentric Orbits , 2003, astro-ph/0302135.

[18]  A. Ghez,et al.  NICMOS Images of the GG Tauri Circumbinary Disk , 2002, astro-ph/0204465.

[19]  W. Kley,et al.  Circumbinary disk evolution , 2002, astro-ph/0204175.

[20]  P. Armitage,et al.  Accretion during the Merger of Supermassive Black Holes , 2002, astro-ph/0201318.

[21]  Jeremy Goodman,et al.  Selfgravity and QSO disks , 2002, astro-ph/0201001.

[22]  J. Papaloizou,et al.  Orbital eccentricity growth through disc-companion tidal interaction , 2001 .

[23]  B. Fryxell,et al.  FLASH: An Adaptive Mesh Hydrodynamics Code for Modeling Astrophysical Thermonuclear Flashes , 2000 .

[24]  T. Schramm,et al.  Intensive monitoring of OJ 287 , 2000 .

[25]  M. Aller,et al.  Radio Monitoring of OJ 287 and Binary Black Hole Models for Periodic Outbursts , 2000 .

[26]  H. Rix,et al.  Binary Black Hole Mergers from Planet-like Migrations , 1999, The Astrophysical journal.

[27]  J. University,et al.  Disk Accretion onto High-Mass Planets , 1999, astro-ph/9910404.

[28]  L. Sparke,et al.  Vertical Instabilities and Off-Plane Orbits in Circumbinary Disks , 1999 .

[29]  J. Papaloizou,et al.  THE EVOLUTION OF A SUPERMASSIVE BINARY CAUSED BY AN ACCRETION DISC , 1998, astro-ph/9812198.

[30]  V. Hubeny,et al.  Non-LTE Models and Theoretical Spectra of Accretion Disks in Active Galactic Nuclei , 1997, astro-ph/0105507.

[31]  J. Papaloizou,et al.  The hydrodynamical response of a tilted circumbinary disc: linear theory and non-linear numerical simulations , 1996, astro-ph/9609145.

[32]  S. Lubow,et al.  Mass Flow through Gaps in Circumbinary Disks , 1996 .

[33]  D. Lin,et al.  Gap Formation in Protoplanetary Disks , 1996 .

[34]  H. Lehto,et al.  OJ 287 Outburst Structure and a Binary Black Hole Model , 1996 .

[35]  P. Cassen,et al.  Resonantly driven nonlinear density waves in protostellar disks , 1994 .

[36]  S. Lubow,et al.  Dynamics of binary-disk interaction. 1: Resonances and disk gap sizes , 1994 .

[37]  S. Lubow.  A model for tidally driven eccentric instabilities in fluid disks , 1991 .

[38]  C. Clarke,et al.  The effect of an external disk on the orbital elements of a central binary , 1991 .

[39]  J. Pringle.  The properties of external accretion discs , 1991 .

[40]  A. Sillanpää,et al.  OJ 287 - Binary pair of supermassive black holes , 1988 .

[41]  B. Sicardy,et al.  On the Physics of Resonant Disk-Satellite Interaction , 1987 .

[42]  S. Baliunas,et al.  A Prescription for period analysis of unevenly sampled time series , 1986 .

[43]  J. Scargle.  Studies in astronomical time series analysis. II - Statistical aspects of spectral analysis of unevenly spaced data , 1982 .

[44]  Peter Goldreich,et al.  Disk-Satellite Interactions , 1980 .

[45]  M. Rees,et al.  Massive black hole binaries in active galactic nuclei , 1980, Nature.

[46]  S. Tremaine,et al.  The excitation of density waves at the Lindblad and corotation resonances by an external potential. , 1979 .

[47]  Victor Szebehely,et al.  Theory of Orbits. , 1967 .

[48]  P. C. Peters.  Gravitational Radiation and the Motion of Two Point Masses , 1964 .