General relativistic magnetohydrodynamic simulations of magnetically choked accretion flows around black holes

By J. McKinney, A. Tchekhovskoy, R. Stanford, Princeton. 2012

721 citations recorded by the source corpus.

Black hole (BH) accretion flows and jets are qualitatively affected by the presence of ordered magnetic fields. We study fully three-dimensional global general relativistic magnetohydrodynamic (MHD) simulations of radially extended and thick (height H to cylindrical radius R ratio of |H/R| {approx} 0.2-1) accretion flows around BHs with various dimensionless spins (a/M, with BH mass M) and with initially toroidally-dominated ({phi}-directed) and poloidally-dominated (R-z directed) magnetic fields. Firstly, for toroidal field models and BHs with high enough |a/M|, coherent large-scale (i.e. >> H) dipolar poloidal magnetic flux patches emerge, thread the BH, and generate transient relativistic jets. Secondly, for poloidal field models, poloidal magnetic flux readily accretes through the disk from large radii and builds-up to a natural saturation point near the BH. While models with |H/R| {approx} 1 and |a/M| {le} 0.5 do not launch jets due to quenching by mass infall, for sufficiently high |a/M| or low |H/R| the polar magnetic field compresses the inflow into a geometrically thin highly non-axisymmetric 'magnetically choked accretion flow' (MCAF) within which the standard linear magneto-rotational instability is suppressed. The condition of a highly-magnetized state over most of the horizon is optimal for the Blandford-Znajek mechanism that generates persistent relativistic jets with and 100% efficiency for |a/M| {approx}> 0.9. A magnetic Rayleigh-Taylor and Kelvin-Helmholtz unstable magnetospheric interface forms between the compressed inflow and bulging jet magnetosphere, which drives a new jet-disk oscillation (JDO) type of quasi-periodic oscillation (QPO) mechanism. The high-frequency QPO has spherical harmonic |m| = 1 mode period of {tau} {approx} 70GM/c{sup 3} for a/M {approx} 0.9 with coherence quality factors Q {approx}> 10. Overall, our models are qualitatively distinct from most prior MHD simulations (typically, |H/R| << 1 and poloidal flux is limited by initial conditions), so they should prove useful for testing accretion-jet theories and measuring a/M in systems such as SgrA* and M87.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/09bc22c9d6fa2ceb442025201e5a5b7e53334875

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

GRMHD simulations of magnetized advection‐dominated accretion on a non‐spinning black hole: role of outflows (2012, methodology): “0BtN10 in McKinney et al. (2012) agree on the following key result: out to radii ∼50–100, ADAF/SANE systems have negligible mass outflow.”
The Masses and Spins of Neutron Stars and Stellar-Mass Black Holes (2014, background): “Alternatively, it may be the case that QPO frequencies are not disk frequencies; some models predict QPOs produced at the coronal base of a jet [314].”
Three-dimensional simulations of supercritical black hole accretion discs - luminosities, photon trapping and variability (2015, background): “The hope was that the single loop would lead to a strong magnetic field at the horizon and would give a magnetically arrested disk (Igumenshchev et al. 2003; Narayan et al. 2003; Tchekhovskoy et al. 2011; McKinney et al. 2012).”
LOCAL STUDY OF ACCRETION DISKS WITH A STRONG VERTICAL MAGNETIC FIELD: MAGNETOROTATIONAL INSTABILITY AND DISK OUTFLOW (2012, background): “More recently, Tchekhovskoy et al. (2011), McKinney et al. (2012) and Narayan et al. (2012) studied the accretion flow with large scale initial poloidal field in the inner disk with β0 ∼ 102 which leads to a “magnetically arrested” or “magnetically chocked” accretion flow due to the accumulation of…”
Superradiance (2015, background): “In general both the accretion process and the BZ mechanism might contribute to the energy released in the jets, making it difficult to prove from numerical simulations that the latter mechanism is at work, but recent general relativistic magnetohydrodynamic (GRMHD) simulations seem to indicate that ”
Superradiance: Energy Extraction, Black-Hole Bombs and Implications for Astrophysics and Particle Physics (2015, background): “Recently, efficiencies up to ηjet ∼ 300% have been obtained in GRMHD simulations [460, 445, 446, 443] which is a strong indication that the BZ mechanism is at work.”
Hot Accretion Flows Around Black Holes (2014, methodology): “…Kuwabara et al. 2000; Hawley & Balbus 2002; Koide 2003; McKinney & Gammie 2004; Kato et al. 2004a, 2004b; De Villiers et al. 2005; McKinney 2005, 2006; Hawley & Krolik 2006; Komissarov et al. 2007; McKinney & Blandford 2009; Tchekhovskoy et al. 2011; McKinney et al. 2012, Sadowski et al. 2013a).”
First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring (2019, positive): “At 15maxf f> ~ , 111 numerical simulations show that the accumulated magnetic flux erupts, pushes aside the accretion flow, and escapes (Tchekhovskoy et al. 2011; McKinney et al. 2012).”
Numerical simulations of super-critical black hole accretion flows in general relativity (2013, methodology): “This structure is specific only to rotating BH and may be identified with the ’disk jet’ found in numerical simulations of optically thin disks (McKinney et al. 2012; Tchekhovskoy & McKinney 2012a; Tchekhovskoy et al. 2012b; Sa̧dowski et al. 2013b; Yuan & Narayan 2014).”
Swift J1644+57 gone MAD: the case for dynamically-important magnetic flux threading the black hole in a jetted tidal disruption event (2013, background): “…(Reis et al. 2012) τQPO = 210 ± 30 s. (24) with the predicted MAD QPO, which occurs at a frequency that is 1/4 of BH horizon angular frequency (McKinney et al. 2012b), ΩH = ac/(2rH) = ωHc/(2rg), resulting in a predicted period τMAD = 2π 0.25ΩH = 16π ωH rg c = 24.8 M•,5 ω−1H s.…”
SUPERNOVA LIGHT CURVES POWERED BY FALLBACK ACCRETION (2012, background): “The actual value of s is highly uncertain, but s = 1 is a reasonable choice (e.g., Igumenshchev & Abramowicz 2000; Pen et al. 2003; Begelman 2012; McKinney et al. 2012), in which case the total outflow rate integrated over disk radius is, Ėw = ξṀfbc 2 2rfb log ( rfb rin ) , (3) where rin is the…”
Time-dependent 3D magnetohydrodynamic pulsar magnetospheres: oblique rotators (2012, methodology): “We apply at the outer r-boundary standard outflow boundary conditions (BCs), at θ -boundaries transmissive polar BCs (McKinney et al. 2012) and at ϕ-boundaries periodic BCs.”
Detection of orbital motions near the last stable circular orbit of the massive black hole SgrA* (2018, background): “So the face-on geometry we infer may be unrelated to the black hole spin direction, unless the accretion flow is brought into alignment for example by magnetic torques (McKinney et al. 2012; Sorathia et al. 2013).”
Long-term GRMHD simulations of neutron star merger accretion discs: implications for electromagnetic counterparts (2018, background): “(35) Following McKinney et al. (2012), we compute the kinetic, en- c© 2014 RAS, MNRAS 000, 1–22 thalpy, and electromagnetic components separately: Ėk(r) = − ∮ ρur(1 + ut) √−gdxθdxφ (36) Ėth(r) = − ∮ ( + P)urut √−gdxθdxφ (37) ĖEM(r) = − ∮ [ (bµbµ) urut − brbt ] √−gdxθdxφ, (38) respectively, where ”
Semi-implicit scheme for treating radiation under M1 closure in general relativistic conservative fluid dynamics codes (2012, methodology): “To solve this issue we can either modify the values of the Christoffel symbols suitably (appendix of McKinney et al. 2012) or we can reformulate the equations so as to avoid the problem.”