# Transient High-energy Gamma-rays and Neutrinos from Nearby Type II Supernovae

## TL;DR

This paper models the production of high-energy gamma-rays and neutrinos from Type II supernovae interacting with dense circumstellar winds, predicting detectable signals within days for nearby events and assessing their contribution to diffuse neutrino flux.

## Contribution

It provides detailed, time-dependent calculations of gamma-ray and neutrino emissions from Type II SNe with wind environments, highlighting detection prospects and flux contributions.

## Key findings

- Multi-GeV and TeV gamma-rays detectable within days for nearby supernovae.
- Neutrino flux contribution from wind breakouts is subdominant unless the wind is very dense.
- Detection prospects improve with denser wind environments and closer supernovae.

## Abstract

The dense wind environment (or circumstellar medium) may be ubiquitous for the regular Type II supernovae (SNe) before the explosion, the interaction of which with the SN ejecta could result in a wind breakout event. The shock generated by the interaction of the SN ejecta and the wind can accelerate the protons and subsequently the high-energy gamma-rays and neutrinos could arise from the inelastic pp collisions. In this work, we present the detailed calculations of gamma-ray and neutrino production for the regular Type II SNe. The calculation is executed by applying time-dependent evolutions of dynamic and proton distribution so that the emission could be shown at different times. Our results show, for the SN 2013fs-like wind environment, the multi-GeV and ~ few-100 TeV gamma-rays are detectable with a time window of several days at <~ 2-3 Mpc by Fermi/LAT and CTA during the ejecta-wind interaction, respectively, and can be detected at a further distance if the wind environment is denser. Besides, we found the contribution of the wind breakouts of regular Type II SNe to diffuse neutrino flux is subdominant by assuming all Type II SNe are SN 2013fs-like, whereas for a denser wind environment the contribution could be conspicuous above 300TeV.