SN2022jli modeled with a $^{56}$Ni double-layer and a magnetar

TL;DR

This paper models the unusual light curve of SN 2022jli using a hybrid approach combining a magnetar engine and a double-layer $^{56}$Ni distribution, successfully explaining its double peaks and rapid decline.

Contribution

It introduces a combined magnetar and nickel-layer model to accurately reproduce the supernova's unique light curve features.

Findings

Best-fit magnetar has a 22 ms spin period and 5×10^{14} G magnetic field.

Nickel is distributed in two shells totaling 0.15 M$_\odot$ within an 11 M$_\odot$ star.

Rapid magnetar energy shutdown explains the steep luminosity drop at 270 days.

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 $^{56}$Ni distribution. The best-fitting case consist of a magnetar with a spin period of $P\simeq 22$ ms and a bipolar magnetic field strength of $B\simeq 5\times 10^{14}$ G and a radioactive content with total nickel mass of 0.15 M$_\odot$, distributed across two distinct shells within a pre-SN structure of 11 M$_\odot$. To reproduce the abrupt drop in luminosity at $\sim 270$ d, the energy deposition from the magnetar must be rapidly and effectively switched off.