# Introduction to multi-messenger astronomy

## TL;DR

This paper introduces multi-messenger astronomy, discussing observational techniques, sources, and physical processes involving photons, neutrinos, cosmic rays, and gravitational waves, highlighting its interdisciplinary approach to understanding the universe.

## Contribution

It provides an introductory overview of multi-messenger astronomy, covering observational methods, source types, and physical processes across different messenger particles.

## Key findings

- Overview of observational techniques for each messenger
- Classification of astronomical sources by messenger type
- Discussion of physical processes producing and propagating messengers

## Abstract

The new field of multi-messenger astronomy aims at the study of astronomical sources using different types of "messenger" particles: photons, neutrinos, cosmic rays and gravitational waves. These lectures provide an introductory overview of the observational techniques used for each type of astronomical messenger, of different types of astronomical sources observed through different messenger channels and of the main physical processes involved in production of the messenger particles and their propagation through the Universe.