Wolf-Rayet stars are a violent and self-destructive phase of a massive star’s lifetime. This is the point at which they begin to die as a prelude to a supernova and black hole formation. Often, large nebulae can be found around these bright stellar objects (pictured), emitting strong ultraviolet radiation. As Wolf-Rayet (WR) stars continue to lose huge amounts of mass and deplete all their fuel, they become even more unstable, resulting in a huge supernova. Exploding WR stars have been linked with powerful gamma ray (γ-ray) bursts; in fact the largest, most distant GRB was observed on March 19th in the constellation of Boötes by NASA’s Swift Observatory and the Polish “Pie of the Sky” GRB detector. There is some evidence that this GRB was the result of a WR star/neutron star binary pair, but what would happen if a WR star is sitting close to an O-type star just as it explodes?
As the WR star collapses, a shock wave (containing hot, relativistic electrons) sent hurtling toward the O-type star may cause inverse Compton scattering of the stellar photon field, generating powerful, long period emissions of γ-ray radiation. New research suggests that this mechanism may explain the 1-100 GeV γ-rays observed minutes or hours after the main GRB…
Continue reading “Collapsing Wolf-Rayet Stars and Inverse Compton Scattering of Stellar Photons”
astroengine.com 