Prototyping non-equilibrium viscous-timescale accretion theory using LMC X-3

Abstract

Explaining variability observed in the accretion flows of black hole X-ray binary systems remains challenging, especially concerning timescales less than, or comparable to, the viscous timescale but much larger than the inner orbital period despite decades of research identifying numerous relevant physical mechanisms. We take a simplified but broad approach to study several mechanisms likely relevant to patterns of variability observed in the persistently high-soft Roche-lobe overflow system LMC X-3. Based on simple estimates and upper bounds, we find that physics beyond varying disk/corona bifurcation at the disk edge, Compton-heated winds, modulation of total supply rate via irradiation of the companion, and the likely extent of the partial hydrogen ionization instability is needed to explain the degree, and especially the pattern, of variability in LMC X-3 largely due to viscous dampening. We then show how evaporation--condensation may resolve or compound the problem given the uncertainties associated with this complex mechanism and our current implementation. We briefly mention our plans to resolve the question, refine and extend our model, and alternatives we have not yet explored.

14 pages, 13 figures

References in corpus (10)

• Modelling the behaviour of accretion flows in X-ray binaries
• MHD simulations of jet acceleration from Keplerian accretion disks: the effects of disk resistivity
• The Existence of Inner Cool Disks in the Low Hard State of Accreting Black Holes
• Re-condensation from an ADAF into an inner disk - the intermediate state of black hole accretion?
• Where is the Radiation Edge in Magnetized Black Hole Accretion discs?
• Viscous Torque and Dissipation in the Inner Region of a Thin Accretion Disk: Implications for Measuring Black Hole Spin
• Time-dependent models of two-phase accretion discs around black holes
• Hysteresis of spectral evolution in the soft state of black-hole binary LMC X-3
• Effects of Compton Cooling on Outflow in a Two Component Accretion Flow around a Black Hole: Results of a Coupled Monte Carlo-TVD Simulation
• Hydrodynamic simulations of irradiated secondaries in dwarf novae