Different approaches to the study of the gravitational radiation emitted by astrophysical sources

TL;DR

This paper reviews various methods for studying gravitational waves from astrophysical sources, focusing on their spectral features, background contributions, and the signatures of different emitting objects like stars and black holes.

Contribution

It introduces approaches to analyze gravitational radiation, including spectral estimation of stochastic backgrounds and source signature identification, highlighting differences between stars and black holes.

Findings

Spectral properties of gravitational wave background can be estimated from energy spectra and star formation rates.

Stars emit signals with identifiable signatures of their nature, unlike black holes.

The stochastic background of gravitational waves is influenced by the history of star formation.

Abstract

Stars and black holes are sources of gravitational radiation in many phases of their life, and the signals they emit exhibit features that are characteristic of the generating process. Emitted since the beginning of star formation, these signals also contribute to create a stochastic background of gravitational waves. We shall show how the spectral properties of this background can be estimated in terms of the energy spectrum of each single event and of the star formation rate history, which is now deducible from astronomical observations. We shall further discuss the process of scattering of masses by stars and black holes, showing that, unlike black holes, stars emit signals that carry a clear signature of the nature of the source.