Supernova interactions with aspherical circumstellar material I: calculations of light curves, AB magnitudes, spectra, and polarisation

TL;DR

This paper presents advanced 2D simulations of supernova interactions with aspherical circumstellar material, analyzing resulting light curves, spectra, and polarisation to better understand observable features.

Contribution

It introduces detailed numerical models of supernova-CSM interactions with aspherical geometries, including polarisation and spectral predictions, using upgraded radiation-hydrodynamic and Monte Carlo transfer codes.

Findings

RHD models show slower expansion velocities than previous adiabatic models.

Light curves exhibit smooth evolution in disc interactions and variability in lobes.

Comparison with real events aids in selecting accurate CSM configurations.

Abstract

We present an upgraded detailed numerical calculations of supernova (SN) interactions with significantly aspherical circumstellar matter (CSM), primarily formed as a disc or bipolar lobes. The circumstellar disc can arise as a result of, for example, mass transfer in a binary, while bipolar lobes can be the result of a violent pre-explosive ejection of matter, similar to the iconic cases of luminous blue variable stars (LBVs). We numerically simulate the radiation-hydrodynamic (RHD) behaviour of interaction processes using a 2D cylindrical version of the RHD code CASTRO. We then calculate light curves, spectral patterns, and polarisation profiles, all up to a relatively long time of two years after an SN shock breakout and from different directions, using the multidimensional Monte Carlo radiation transfer (MC-RT) codes SEDONA and SIROCCO. We calculated a total of five models for the two aforementioned configurations of the surrounding CSM, for stratified density levels, comparing the simulated hydrodynamic behaviour and differences in their observable properties. RHD models exhibit similar behaviour to previous adiabatic models, but with a significantly slower expansion velocity. The calculated light curves show a relatively smooth evolution in SN-disc interaction, and declines and brightening in SN-lobes interaction. Comparing models with real events with a presumed similar physical process provides guidance for selecting a more accurate CSM configuration when simulating real situations.