Multi-dimensional simulations of the expanding supernova remnant of SN 1987A

TL;DR

This paper uses three-dimensional simulations combining hydrodynamics, shock acceleration, and magnetic field modeling to understand the asymmetric radio morphology and shock dynamics of SN 1987A's remnant over 820 to 10,000 days.

Contribution

It introduces a comprehensive 3D simulation approach that integrates multiple physical processes to replicate observed features of SN 1987A's remnant, including asymmetry and radio emission evolution.

Findings

Asymmetric explosion and magnetic field amplification explain the remnant's radio morphology.

Simulation matches observed shock radius and velocity evolution from days 2000 to 7000.

Predicted reversal of asymmetry after day 7000 as shocks exit the equatorial ring.

Abstract

The expanding remnant from SN 1987A is an excellent laboratory for investigating the physics of supernovae explosions. There are still a large number of outstanding questions, such the reason for the asymmetric radio morphology, the structure of the pre-supernova environment, and the efficiency of particle acceleration at the supernova shock. We explore these questions using three-dimensional simulations of the expanding remnant between days 820 and 10,000 after the supernova. We combine a hydrodynamical simulation with semi-analytic treatments of diffusive shock acceleration and magnetic field amplification to derive radio emission as part of an inverse problem. Simulations show that an asymmetric explosion, combined with magnetic field amplification at the expanding shock, is able to replicate the persistent one-sided radio morphology of the remnant. We use an asymmetric Truelove & McKee progenitor with an envelope mass of $10 M_{\sun}$ and an energy of $1.5 \times 10^{44} J$. A termination shock in the progenitor's stellar wind at a distance of $0\farcs43-0\farcs51$ provides a good fit to the turn on of radio emission around day 1200. For the H\textsc{ii} region, a minimum distance of $0\farcs63\pm0\farcs01$ and maximum particle number density of $(7.11\pm1.78) \times 10^7$ m$^{-3}$ produces a good fit to the evolving average radius and velocity of the expanding shocks from day 2000 to day 7000 after explosion. The model predicts a noticeable reduction, and possibly a temporary reversal, in the asymmetric radio morphology of the remnant after day 7000, when the forward shock left the eastern lobe of the equatorial ring.