2025A&A...700L..17O

Context. We study the bolometric evolution of the exceptional Type Ic supernova SN 2022jli, aiming to understand the underlying mechanisms responsible for its distinctive double-peaked light curve morphology, extended timescales, and the rapid, steep decline in luminosity observed at around 270 days after the SN discovery.
Aims. We present a quantitative assessment of two leading models through the use of hydrodynamic radiative simulations: two shells enriched with nickel and a combination of nickel and magnetar power.
Methods. We explored the parameter space of a model in which the supernova (SN) is powered by radioactive decay while assuming a bimodal nickel distribution. Though this setup can reproduce the early light curve properties, it faces problems explaining the prominent second peak. We therefore considered a hybrid scenario with a rapidly rotating magnetar as an additional energy source.
Results. We find that the observed light curve morphology can be well reproduced by a model combining a magnetar engine and a double-layer ⁵⁶Ni distribution. The best-fitting case consists of a magnetar with a spin period of P ≃ 22 ms and a bipolar magnetic field strength of B ≃ 5 × 10¹⁴ G and a radioactive content with a total M(⁵⁶Ni) of 0.15 M_⊙ distributed across two distinct shells within a pre-SN structure of 11 M_⊙. To reproduce the abrupt drop in luminosity at ∼270 d, the energy deposition from the magnetar must be rapidly and effectively switched off.