High compactness progenitors and the formation of collapsars and magnetars

Objective

Core-collapse supernovae are bright astrophysical transients associated with a key stage in the evolution of massive stars: their death. Overall, observations and theoretical pursuits have given us a fantastic end-to-end picture of these events. Long gamma-ray bursts are associated with a very small fraction of these dying stars and stand out due to their extreme nature, including their extreme energies. Compared to typical supernovae, the inner workings of these events are more obscured. The leading mechanism underlying long gamma-ray bursts is the collapsar mechanism, a multifaceted and intricate process. Critical components contributing to its occurrence encompass a wide range of phenomena, from the initial progenitor evolution, through the core-collapse evolution leading to a failed supernova, to the subsequent formation of an accretion disk, the generation of relativistic jets, and ultimately the resulting electromagnetic emission. This complexity and the interdependence of these stages have posed significant challenges to achieving a comprehensive end-to-end understanding of this scenario. Recent advances in our understanding of the explosion mechanism in high compactness progenitors are challenging the idea that the proposed progenitors of long gamma ray bursts actually undergo a failed supernova. Instead, there is compelling evidence that they explode! By performing long-term state-of-the-art neutrino-radiation magnetohydrodynamic simulations of long gamma-ray burst progenitors, this ERC consolidator grant promises to deliver a unifying picture of extreme electromagnetic transients. These transients include not only long gamma-ray bursts, but also Type Ic-BL supernovae and superluminous supernovae. This unified picture will be enabled by detailed microphysics and modern computational techniques beyond the current state-of-the-art for supernovae. From this, we will revolutionise our understanding of these extreme events.