Why equal ejecta masses yield higher 56Ni and kinetic energies in Type Ic-BL supernovae

Determine the physical mechanism(s) by which broad-lined Type Ic supernovae, despite having ejecta masses comparable to those of normal stripped-envelope core-collapse supernovae, synthesize larger amounts of 56Ni and achieve higher kinetic energies.

Background

Broad-lined Type Ic supernovae exhibit faster-rising, more luminous light curves and broader spectral features than normal stripped-envelope supernovae, implying higher kinetic energies and larger 56Ni yields. However, modeling often indicates ejecta masses that are similar to those of normal stripped-envelope events. This apparent discrepancy challenges standard core-collapse supernova explosion scenarios.

Resolving this tension is central to understanding whether additional power sources (e.g., jet-driven energy injection or magnetar spin-down) or different explosion dynamics are required to explain the enhanced 56Ni production and kinetic energy in events with similar ejecta masses.