Supernova ejecta interacting with a circumstellar disk. I. two-dimensional radiation-hydrodynamic simulations

TL;DR

This study uses two-dimensional radiation-hydrodynamic simulations to explore how supernova ejecta interact with circumstellar disks, revealing effects on light curves and viewing angle dependence, with implications for understanding aspherical supernovae.

Contribution

It is the first to perform detailed 2D simulations of ejecta-disk interactions, capturing hydrodynamic instabilities and viewing angle effects on supernova light curves.

Findings

Ejecta-disk interaction causes significant viewing angle dependence.

Hydrodynamic instabilities develop at the ejecta-CSM interface.

Light curves are smeared out when viewed through the disk.

Abstract

We perform a series of two-dimensional radiation-hydrodynamic simulations of the collision between supernova ejecta and circumstellar media (CSM). The hydrodynamic interaction of a fast flow and the surrounding media efficiently dissipates the kinetic energy of the fast flow and considered as a dominant energy source for a specific class of core-collapse supernovae. Despite some observational evidence for aspherical ejecta and/or CSM structure, multi-dimensional effects in the ejecta-CSM interaction are relatively unexplored. Our numerical simulations equipped with an adaptive mesh refinement technique successfully reproduce hydrodynamic instabilities developing around the ejecta-CSM interface. We also investigate effects of disk-like CSM on the dynamical evolution of supernova ejecta and bolometric light curves. We find that emission powered by ejecta-disk interaction exhibits significant viewing angle dependence. For a line of sight close to the symmetry axis, the observer directly sees the supernova ejecta, leading to a short brightening timescale. For an observer seeing the emission through the CSM disk, thermal photons diffuse throughout the CSM and thus the light curve is severely smeared out.