The Influence of Magnetic Field Geometry on the Evolution of Black Hole Accretion Flows: Similar Disks, Drastically Different Jets

By Kristian Beckwith, J. Hawley, Julian Krolik. 2007

225 citations recorded by the source corpus.

Because the magnetorotational instability is capable of exponentially amplifying weak pre-existing magnetic fields, it might be hoped that the character of the magnetic field in accretion disks would be independent of the nature of the seed field. However, the divergence-free nature of magnetic fields in highly conducting fluids ensures that their large-scale topology is preserved, no matter how greatly the field intensity is changed. By performing global two- and three-dimensional general relativistic magnetohydrodynamic disk simulations with several different topologies for the initial magnetic field, we explore the degree to which the character of the flows around black holes depends on the initial topology. We find that while the qualitative properties of the accretion flow are nearly independent of field topology, jet launching is very sensitive to it; a sense of vertical field consistent for at least an inner disk inflow time is essential to the support of strong jets.

Subfields: Astronomy and Astrophysics, Geophysics

View Paper: https://www.semanticscholar.org/paper/096403bc67aca4c4c6ef28b9329ae2f9d5356991

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Citations in the corpus

A Reconnection Switch to Trigger gamma-Ray Burst Jet Dissipation (2010, background): “Of relevance to GRBs is that a dipolar field appears to be required to launch a jet from the BH (Beckwith et al. 2008; McKinney & Blandford 2009), yet magnetic field advection from a presupernova core collapsing on to a BH leads to too small a magnetic flux to generate the power of a cosmological…”
ASSESSING QUANTITATIVE RESULTS IN ACCRETION SIMULATIONS: FROM LOCAL TO GLOBAL (2011, background): “We might hope that these choices have little effect on the outcome, but that must be demonstrated; in the case of jet-launching, we already know that magnetic field geometry plays a major role (Beckwith et al. 2008a).”
Simulations of magnetized discs around black holes: Effects of black hole spin, disc thickness and magnetic field geometry (2010, methodology): “…factor in drawing firm conclusions from such studies is that the assumed initial global magnetic field geometry and strength can significantly change the magnitude of electromagnetic stresses and associated angular momentum transport inside the ISCO (McKinney & Gammie 2004; Beckwith et al. 2008a).”
RADIATIVE MODELS OF SGR A* FROM GRMHD SIMULATIONS (2009, background): “At R Rmax the accretion flow soon reaches a nearly (statistically) stationary state that is independent of the initial conditions (except for the magnetic field geometry; see Hawley & Krolik 2002; Beckwith et al. 2008).”
General relativistic magnetohydrodynamic simulations of magnetically choked accretion flows around black holes (2012, methodology): “Indeed, production of persistent relativistic jets may require steady largescale dipolar (i.e. sub-dominant higher multipoles) fields near BHs (Beckwith et al. 2008a; McKinney & Blandford 2009).”
Neutrino-dominated accretion flows as the central engine of gamma-ray bursts (2017, background): “…(2D or 3D) MHD simulations have investigated on how a large-scale vertical magnetic field evolves with an accretion disk and which configurations may power a jet (e.g., McKinney & Gammie 2004; Beckwith et al. 2008, 2009; McKinney & Blandford 2009), yet the analytic form of f (a∗) is still unclear.”
Prograde and retrograde black holes: whose jet is more powerful? (2012, background): “Changes in the flux can significantly affect simulated jet efficiencies (McKinney & Gammie 2004; McKinney 2005; Beckwith et al. 2008) and render them unreliable.”
Stability of relativistic jets from rotating, accreting black holes via fully three-dimensional magnetohydrodynamic simulations (2008, methodology): “GRMHD simulations show that no strong jet emerges due to the accretion of higher multipole moments put initially withinthe disc (McKinney & Gammie 2004; McKinney & Narayan 2007a,b; c© 2009 RAS, MNRAS000, 1–6 Beckwith et al. 2008).”
Hot Accretion Flows Around Black Holes (2014, background): “…where the disk wind is launched (§3.4) The effect of different initial magnetic field geometries has been investigated by a number of authors (e.g., Hawley & Krolik 2002, Igumenshchev et al. 2003 with a pseudo-Newtonian potential; and Beckwith et al. 2008, McKinney & Blandford 2009 with GRMHD).”
Three-Dimensional Simulations of Magnetized Thin Accretion Disks around Black Holes: Stress in the Plunging Region (2008, methodology): “Beckwith et al. (2008b) suggest a larger deviation from NT73, but they considered a torus with a larger value of h/r and did not use a self-consistent dissipation model.”
Black Hole Spin via Continuum Fitting and the Role of Spin in Powering Transient Jets (2013, background): “GRMHD simulations of accreting black holes have found MHD jets forming spontaneously from generic initial conditions (e.g., Koide et al. 2002; McKinney & Gammie 2004; McKinney 2005; Beckwith et al. 2008; McKinney & Blandford 2009).”
Three-dimensional general relativistic radiation magnetohydrodynamical simulation of super-Eddington accretion, using a new code HARMRAD with M1 closure (2013, background): “…initial conditions lead to evolved disk states of various disk thicknesses, such as |H/R| ∼ 0.1–0.15 (Hawley & Krolik 2001; De Villiers et al. 2003; Beckwith et al. 2008b,a, 2009) and |H/R| ∼ 0.2 (Hawley & Balbus 2002; Machida et al. 2000; Martı́ & Müller 2003; McKinney & Gammie 2004; Fragile…”
The black hole accretion code (2016, methodology): “To facilitate a quantitative comparison, we report radial profiles of disk-averaged quantities similar to [67, 125, 144].”
NONSTEADY ACCRETION IN PROTOSTARS (2008, background): “Global disk simulations (Hirose et al. 2004; McKinney & Narayan 2007; Beckwith et al. 2008), local disk simulations in which the mean field is allowed to evolve because of the boundary conditions (Brandenburg et al. 1995), and observations of the galactic disk (Vallee 2004) all exhibit a “mean”…”