Spectral and temporal modelling of the most radio luminous colliding wind binary
The luminous, massive Wolf-Rayet (WR) stars are thought to be immediate precursors to core-collapse supernovae. A subset of WR stars occur in colliding wind binaries - where the collision of the stellar winds produces bright radio and infrared radiation. Dust formation within such colliding wind binary environments has produced a small handful of beautiful exemplar systems in which the wake behind the wind shock is wrapped into a spiral, encoding the orbital parameters of the system. In this talk I will present the WR binary system Apep, which displays a host of features that suggest one of the components is a rapidly rotating WR star. Such a composition would make Apep a Galactic progenitor system to a long-duration gamma-ray burst. In particular, I will outline the long-term radio monitoring campaign of Apep, and how radio spectral and temporal modelling of the system can be used to test the shock physics and orbital dynamics of this unique system.
