Annual modulation of the Galactic binary confusion noise bakground and LISA data analysis

TL;DR

This paper investigates how the anisotropic Galactic binary confusion noise affects LISA's data analysis, revealing that the noise level varies seasonally and depends on the detector's orientation.

Contribution

It introduces a detailed analysis of the anisotropies in the Galactic confusion noise and their impact on LISA data interpretation, highlighting seasonal variations.

Findings

Confusion noise level varies by a factor of 2 over three months.

Minimum noise occurs near spring or autumn equinox.

Off-diagonal components in the noise matrix depend on detector orientation.

Abstract

We study the anisotropies of the Galactic confusion noise background and its effects on LISA data analysis. LISA has two data streams of the gravitational waves signals relevant for low frequency regime. Due to the anisotropies of the background, the matrix for their confusion noises has off-diagonal components and depends strongly on the orientation of the detector plane. We find that the sky-averaged confusion noise level $\sqrt {S(f)}$ could change by a factor of 2 in three months, and would be minimum when the orbital position of LISA is either around the spring or autumn equinox.