Unveiling the gravitational universe at μ-Hz frequencies

Alberto Sesana , Natalia Korsakova (1) , Manuel Arca Sedda , Vishal Baibhav , Enrico Barausse , Simon Barke , Emanuele Berti , Matteo Bonetti , Pedro R Capelo , Chiara Caprini (2) , Juan Garcia-Bellido , Zoltan Haiman , Karan Jani , Oliver Jennrich , Peter H Johansson , Fazeel Mahmood Khan , Valeriya Korol , Astrid Lamberts (1) , Alessandro Lupi , Alberto Mangiagli , Lucio Mayer , Germano Nardini , Fabio Pacucci , Antoine Petiteau (2) , Alvise Raccanelli , Surjeet Rajendran , John Regan , Lijing Shao , Alessandro D. A. M. Spallicci (3) , Nicola Tamanini (4) , Marta Volonteri (5) , Niels Warburton , Kaze Wong , Miguel Zumalacarregui

1 OCA - Observatoire de la Côte d'Azur
2 APC (UMR_7164) - AstroParticule et Cosmologie
3 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
4 L2IT - Laboratoire des deux Infinis de Toulouse
5 IAP - Institut d'Astrophysique de Paris

We propose a space-based interferometer surveying the gravitational wave (GW) sky in the milli-Hz to μ-Hz frequency range. By the 2040s, the μ-Hz frequency band, bracketed in between the Laser Interferometer Space Antenna (LISA) and pulsar timing arrays, will constitute the largest gap in the coverage of the astrophysically relevant GW spectrum. Yet many outstanding questions related to astrophysics and cosmology are best answered by GW observations in this band. We show that a μ-Hz GW detector will be a truly overarching observatory for the scientific community at large, greatly extending the potential of LISA. Conceived to detect massive black hole binaries from their early inspiral with high signal-to-noise ratio, and low-frequency stellar binaries in the Galaxy, this instrument will be a cornerstone for multimessenger astronomy from the solar neighbourhood to the high-redshift Universe.

Keywords: Space gravitational wave detector; Micro-Hz band; Massive black hole binaries; Multimessenger and multiband Astronomy; General relativity and beyond; Cosmology and cosmography; Milky Way science; Astrophysics - Instrumentation and Methods for Astrophysics; Astrophysics - High Energy Astrophysical Phenomena; General Relativity and Quantum Cosmology

Domains: Sciences of the Universe [physics]

Alberto Sesana, Natalia Korsakova, Manuel Arca Sedda, Vishal Baibhav, Enrico Barausse, et al.. Unveiling the gravitational universe at μ-Hz frequencies. Experimental Astronomy, 2021, ⟨10.1007/s10686-021-09709-9⟩. ⟨insu-03336222⟩