Spatially Filtering the Binary Confusion Noise for Space Gravitational Wave Detectors

TL;DR

This paper proposes a spatial filtering method based on the Doppler shift of binary star signals, significantly reducing galactic binary confusion noise in space gravitational wave detectors, thereby enhancing sensitivity.

Contribution

It introduces a novel spatial filtering technique that leverages position-dependent Doppler shifts to mitigate confusion noise from galactic binaries in gravitational wave detection.

Findings

Spatial filtering reduces galactic binary confusion noise.

Sensitivity is limited only by instrument noise, not confusion background.

The method enables clearer detection of monochromatic sources.

Abstract

For the last fifteen years, the limiting noise source at the low frequency end of the sensitivity window for space gravitational wave detectors has been expected to be the confusion background of overlapping galactic binary stars. Here, we present results of a study that investigates the correlation between binary star signals and conclude that there is a spatial filter in the position-dependent Doppler shift of each binary that sharply reduces the contribution of the galactic binary confusion to the noise in the detector when a monochromatic source is being detected. The sensitivity is thus determined by the instrument alone, and the confusion noise may effectively be ignored.