Alternative LISA-TAIJI networks: detectability of the isotropic stochastic gravitational wave background

TL;DR

This study compares different proposed LISA-TAIJI network configurations for their effectiveness in detecting the stochastic gravitational wave background, finding that the LISA-TAIJIm configuration is highly competitive and suitable for joint observations with LISA.

Contribution

The paper evaluates the detectability of the stochastic gravitational wave background for various LISA-TAIJI network configurations, highlighting the optimality of the LISA-TAIJIm setup.

Findings

LISA-TAIJIm is competitive with LISA-TAIJIp for certain SGWB spectral shapes.

LISA-TAIJIm can effectively separate SGWB components by parameter estimation.

LISA-TAIJIm is identified as an optimal configuration for joint observations with LISA.

Abstract

In previous work [1], three TAIJI orbital deployments have been proposed to compose alternative LISA-TAIJI networks, TAIJIm (leading the Earth by $20^\circ$ and $-60^\circ$ inclined with respect to ecliptic plane), TAIJIp (leading the Earth by $20^\circ$ and $+60^\circ$ inclined), TAIJIc (colocated and coplanar with LISA) with respect to the LISA mission (trailing the Earth by $20^\circ$ and $+60^\circ$ inclined). And the LISA-TAIJIm network has been identified as the most capable configuration for massive black hole binary observation. In this work, we examine the performance of three networks to the stochastic gravitational wave background (SGWB) especially for the comparison of two eligible configurations, LISA-TAIJIm and LISA-TAIJIp. This investigation shows that the detectability of LISA-TAIJIm is competitive with the LISA-TAIJIp network for some specific SGWB spectral shapes. And the capability of LISA-TAIJIm is also identical to LISA-TAIJIp to separate the SGWB components by determining the parameters of signals. Considering the performances on SGWB and massive black hole binaries observations, the TAIJIm could be recognized as an optimal option to fulfill joint observations with LISA.