Nonlinear Oscillations in the Longterm Evolution of LMC X-3

Nonlinear Oscillations in the Longterm Evolution of LMC X-3

The black hole binary LMC X-3 exhibits long term intensity variations of a factor of several hundred, with a characteristic time scale of about one hundred days. Presumed to be periodic based on HEAO-1 A2 data (Cowley et al.), RXTE/ASM data reveal a more complex variation, not strictly periodic. We find that times between successive minima are related by rational fractions, suggesting a stable clock in the system driving a nonlinear oscillator. Segments whose lengths are multiples of that clock are extracted from the RXTE ASM light curve and embedded in a phase space reconstructed from the data. The flow in this representation is reminiscent of several well-studied low dimensional dynamical systems.

Phase-space evolution similar to many nonlinear dynamical systems, and markedly dissimilar to random (or periodic) behavior. Note suggestion of two unstable fixed points in the flow (FPi).

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