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Probing anisotropies of gravitational-wave backgrounds with a space-based interferometer III: Reconstruction of a high-frequency skymap

Atsushi Taruya
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Abstract

We develop a numerical scheme to make a high-frequency skymap of gravitational-wave backgrounds (GWBs) observed via space-based interferometer. Based on the cross-correlation technique, the intensity distribution of anisotropic GWB can be directly reconstructed from the time-ordered data of cross-correlation signals, with full knowledge of detector's antenna pattern functions. We demonstrate how the planned space interferometer, LISA, can make a skymap of GWB for a specific example of anisotropic signals. At the frequency higher than the characteristic frequency $f_*=1/(2πL)$, where $L$ is the arm-length of the detector, the reconstructed skymap free from the instrumental noise potentially reaches the angular resolution up to the multipoles $\ell\sim10$. The presence of instrumental noises degrades the angular resolution. The resultant skymap has angular resolution with multipoles $\ell\leq 6\sim7$ for the anisotropic signals with signal-to-noise ratio S/N$>5$.

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Atsushi Taruya. 2006-07-20. Probing anisotropies of gravitational-wave backgrounds with a space-based interferometer III: Reconstruction of a high-frequency skymap. https://doi.org/10.1103/physrevd.74.104022

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