Low-frequency gravitational-wave science with eLISA/NGO

TL;DR

eLISA/NGO is a proposed space mission to detect low-frequency gravitational waves, promising new insights into black hole mergers, galactic binaries, early Universe signals, and tests of general relativity.

Contribution

This paper reviews the expected scientific capabilities and potential discoveries of the eLISA mission in low-frequency gravitational-wave astronomy.

Findings

Detection of massive black hole mergers across cosmic history

Observation of millions of galactic ultracompact binaries

Potential detection of relic gravitational waves from the early Universe

Abstract

We review the expected science performance of the New Gravitational-Wave Observatory (NGO, a.k.a. eLISA), a mission under study by the European Space Agency for launch in the early 2020s. eLISA will survey the low-frequency gravitational-wave sky (from 0.1 mHz to 1 Hz), detecting and characterizing a broad variety of systems and events throughout the Universe, including the coalescences of massive black holes brought together by galaxy mergers; the inspirals of stellar-mass black holes and compact stars into central galactic black holes; several millions of ultracompact binaries, both detached and mass transferring, in the Galaxy; and possibly unforeseen sources such as the relic gravitational-wave radiation from the early Universe. eLISA's high signal-to-noise measurements will provide new insight into the structure and history of the Universe, and they will test general relativity in its strong-field dynamical regime.