SN 2022jli modeled with a 56Ni double layer and a magnetar

Abstract

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. We present a quantitative assessment of two leading models through hydrodynamic radiative simulations: two shells enriched with nickel and a combination of nickel and magnetar power. We explore the parameter space of a model in which the SN is powered by radioactive decay assuming a bimodal nickel distribution. While this setup can reproduce the early light curve properties, it faces problems to explain the prominent second peak. We therefore consider a hybrid scenario with a rapidly rotating magnetar as additional energy source. 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 consist of a magnetar with a spin period of P=22 ms and a bipolar magnetic field strength of B = 5e14 G and a radioactive content with total nickel mass of 0.15 Msun, distributed across two distinct shells within a pre-SN structure of 11 Msun. To reproduce the abrupt drop in luminosity at ~270 d, the energy deposition from the magnetar must be rapidly and effectively switched off.