Asphericity in Type Ic Supernovae: A link to GRBs

摘要

Observational evidence indicates that the outflow of material in many, possibly even all Supernovae, is not spherical. Here we review the evidence in Type Ic SNe associated with Gamma-Ray Bursts (GRB-SNe). These SNe are thought to originate in very massive stars. They are particularly suited to study the details of the collapse process because they are not enshrouded in a thick hydrogen envelope, exposing the inner carbon-oxygen core, near the site of collapse, and because of the link with GRBs. In the more massive stars {M ~ 40M?), observations may be interpreted to indicate that the SN explosion is driven by the mass inflow into the compact remnant, and that this remnant must be a black hole. This seems to be a necessary requirement for the SN also to generate a GRB. For less massive stars (M Rs 20M?), the remnant may be a neutron star and magnetic activity may be responsible for the energetic explosion and an X-ray flash.