Interacting supernovae as high-energy multimessenger transients

TL;DR

This paper models the broadband electromagnetic emission from interacting supernovae with dense circumstellar material, highlighting their potential as high-energy multimessenger transient sources and applying the model to SN 2023ixf.

Contribution

It extends previous models by including electromagnetic cascades and Coulomb losses, providing detailed predictions for high-energy emissions from interacting supernovae.

Findings

Electromagnetic cascades significantly affect MeV and radio emissions.

The model successfully explains observed features of SN 2023ixf.

Interacting supernovae are promising sources for high-energy neutrinos and photons.

Abstract

Multiwavelength observations have revealed that dense, confined circumstellar material (CCSM) commonly exists in the vicinity of supernova (SN) progenitors, suggesting enhanced mass losses years to centuries before their core collapse. Interacting SNe, which are powered or aided by interaction with the CCSM, are considered to be promising high-energy multimessenger transient sources. We present detailed results of broadband electromagnetic emission, following the time-dependent model proposed in the previous work on high-energy SN neutrinos [K. Murase, New prospects for detecting high-energy neutrinos from nearby supernovae, Phys. Rev. D 97, 081301(R) (2018)]. We investigate electromagnetic cascades in the presence of Coulomb losses, including inverse-Compton and synchrotron components that significantly contribute to MeV and high-frequency radio bands, respectively. We also discuss the application to SN 2023ixf.