Searching for Gravitational Waves with a Geostationary Interferometer

TL;DR

This paper evaluates the potential of a geostationary gravitational wave interferometer operating in the sub-Hertz band, highlighting its sensitivity limitations at lower frequencies and its capability to observe smaller super-massive black holes at higher frequencies.

Contribution

The study introduces a geostationary interferometer concept and assesses its sensitivity and observational capabilities compared to existing missions like LISA.

Findings

Less sensitive at low frequencies compared to LISA

Capable of observing SMBHs smaller than 10^6 solar masses

Potential to probe SMBH formation scenarios

Abstract

We analyze the sensitivities of a geostationary gravitational wave interferometer mission operating in the sub-Hertz band. Because of its smaller armlength, in the lower part of its accessible frequency band ($10^{-4} - 2 \times 10^{-2}$ Hz) our proposed Earth-orbiting detector will be less sensitive, by a factor of about seventy, than the Laser Interferometer Space Antenna (LISA) mission. In the higher part of its band instead ($2 \times 10^{-2} - 10$ Hz), our proposed interferometer will have the capability of observing super-massive black holes (SMBHs) with masses smaller than $\sim 10^{6}$ M$_{\odot}$. With good event rates for these systems, a geostationary interferometer will be able to accurately probe the astrophysical scenarios that account for their formation.