Possible implications of VHE gamma-radiation from the X-ray binary Centaurus X-3


We discuss theoretical models that could explain the existing data from $γ$-ray observations of Cen X-3. Because of the high energetics required, any reasonable option for $γ$-ray production in Cen X-3 must be connected with jets emerging from the inner accretion disc of the neutron star. A large-scale quasi-stationary source (on a time scale of days or longer) powered by shocks driven by such jets into the Rs $≥$ 1013 cm surrounding the binary could explain the bulk of the $γ$-radiation features, except for a modulation of the $γ$-ray signal with the pulsar spin period. These modulations, if genuine, would require an alternative source with Rs 1011 cm. We consider two principal models, hadronic and leptonic, for such a compact source in the jet. Both models predict that the pulsed $γ$-ray emission should be episodic, and can be expected only at the initial stages (typically less than a few hours) of powerful $γ$-ray flares, and that $γ$-ray pulsations should be significantly shifted from the pulsar frequency. Such a source would generally fade, due to expansion, in a few days.

Michael Aye
Michael Aye
Research Scientist in Planetary Science

My research interests include remote sensing of surfaces, related machine learning studies and open source software.