# High-Energy Multi-Messenger Transient Astrophysics

## TL;DR

This paper reviews how high-energy particles from astrophysical transients like black holes and neutron stars enhance multi-messenger astronomy, revealing new physics through electromagnetic, neutrino, and gravitational-wave observations.

## Contribution

It provides a comprehensive overview of high-energy particle production in transient astrophysical phenomena and discusses their role in multi-messenger astrophysics.

## Key findings

- High-energy emissions help identify astrophysical sources.
- Multi-messenger observations improve understanding of transient physics.
- Electromagnetic follow-ups are crucial for source characterization.

## Abstract

The recent discoveries of high-energy cosmic neutrinos and gravitational waves from astrophysical objects have led to the new era of multi-messenger astrophysics. In particular, electromagnetic follow-up observations triggered by these cosmic signals proved to be highly successful and brought about new opportunities in the time-domain astronomy. Here we review high-energy particle production in various classes of astrophysical transient phenomena related to black holes and neutron stars, and discuss how high-energy emission can be used to reveal the underlying physics of neutrino and gravitational-wave sources.