Mapping a Stochastic Gravitational Wave Background

Observing Run 1 (GPS 1126623617-1136649617, 20-500 Hz)

Searching for anisotropies in a stochastic gravitational wave background

This page displays results from the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) search for anisotropies in the stochastic gravitational wave background (SGWB).

Data from the two LIGO detectors are cross-correlated to look for an underlying stochastic signal from a gravitational wave background that is coherent between the two detectors. The background spectrum is modelled as a power-law, indexed by α.

Although we haven't yet detected a gravitational wave background, our skymaps tell us how energetic the gravitational wave sky would need to be in order for us to detect it. Our results set upper limits on the energy density of sources of varying angular resolution across the sky. For more detail about our search, you can visit the summary page here or read the paper that presents these results here.

You can toggle between maps of signal-to-noise ratio (SNR) limits or upper limits on the energy density spectrum. You can also toggle between different values of the spectral index α, which are motivated by different background models. Additionally, you can select between different map projections and coordinate systems.

Click-drag with your mouse to control the view (left-click to rotate, right-click to pan), and scroll to zoom. A mouse-over will display the details of the specific point in question (sky position coordinates and data value). Right clicking on a pixel on the map will select it, displaying its value in the top-left of the window.

We hope you enjoy this interactive visualisation of our limits on the energy density of the gravitational wave background.