# Multimessenger Probes of High-energy Sources

## TL;DR

This paper discusses how combining gravitational wave, neutrino, and electromagnetic observations can enhance understanding of the universe's most energetic sources, especially compact stellar remnants, and test their hadronic content.

## Contribution

It proposes a multimessenger approach to study high-energy cosmic sources, focusing on gravitational wave and neutrino joint detections from compact objects.

## Key findings

- Joint detection can reveal source physics and hadronic content.
- Non-detections will constrain hadronic models.
- Focus on binary mergers and core collapse sources.

## Abstract

Multimessenger observations may hold the key to learn about the most energetic sources in the universe. The recent construction of large scale observatories opened new possibilities in testing non thermal cosmic processes with alternative probes, such as high energy neutrinos and gravitational waves. We propose to combine information from gravitational wave detections, neutrino observations and electromagnetic signals to obtain a comprehensive picture of some of the most extreme cosmic processes. Gravitational waves are indicative of source dynamics, such as the formation, evolution and interaction of compact objects. These compact objects can play an important role in astrophysical particle acceleration, and are interesting candidates for neutrino and in general high-energy astroparticle studies. In particular we will concentrate on the most promising gravitational wave emitter sources: compact stellar remnants. The merger of binary black holes, binary neutron stars or black hole-neutron star binaries are abundant gravitational wave sources and will likely make up the majority of detections. However, stellar core collapse with rapidly rotating core may also be significant gravitational wave emitter, while slower rotating cores may be detectable only at closer distances. The joint detection of gravitational waves and neutrinos from these sources will probe the physics of the sources and will be a smoking gun of the presence of hadrons in these objects which is still an open question. Conversely, the non-detection of neutrinos or gravitational waves from these sources will be fundamental to constrain the hadronic content.