| Abstract: | Massive stars end their lives in a catastrophic collapse of their inner core. In all (or most) cases this is followed by a bright transient event termed a core-collapse supernova. A small fraction of the tremendous gravitational energy released is needed to explain the observed energy, although theoretical understanding of this transition is incomplete. The most well-studied theory of core-collapse supernovae is the `delayed neutrino-heating mechanism', which mostly fails in driving successful explosions, or at best produces very low-energy supernovae. Among the alternatives to the delayed neutrino mechanism are jet-driven explosions. Energetic bipolar flows (jets) capable of disrupting a massive star may be launched from accretion disks around the collapsed core that becomes a neutron star. Disk formation, in turn, requires high pre-collapse specific angular momentum. In this talk I will discuss the origins and evolution of angular momentum in collapsing massive stars, and implications for steady or intermittent accretion disks and core-collapse supernovae. |
