Circumstellar interaction in supernovae in dense environments - an observational perspective

TL;DR

This paper reviews how supernovae interacting with dense circumstellar media, especially Type IIn supernovae, reveal details about progenitor stars through their unique radio and X-ray emissions and the effects of high-density environments.

Contribution

It provides an observational perspective on the properties and radiation signatures of supernovae in dense environments, highlighting recent findings on their shock interactions and mass loss behaviors.

Findings

X-ray emission dominated by forward shock

Radio emission affected by free-free absorption

Evidence of episodic mass loss and asymmetry

Abstract

In a supernova explosion, the ejecta interacting with the surrounding circumstellar medium (CSM) give rise to variety of radiation. Since CSM is created from the mass lost from the progenitor star, it carries footprints of the late time evolution of the star. This is one of the unique ways to get a handle on the nature of the progenitor star system. Here, I will focus mainly on the supernovae (SNe) exploding in dense environments, a.k.a. Type IIn SNe. Radio and X-ray emission from this class of SNe have revealed important modifications in their radiation properties, due to the presence of high density CSM. Forward shock dominance of the X-ray emission, internal free-free absorption of the radio emission, episodic or non-steady mass loss rate, asymmetry in the explosion seem to be common properties of this class of SNe.