Imaging through Gravitational Waves

Gravitational-Wave observatories are one of the newest additions to the suite of instruments used by astronomers to study the universe. From the first detection announced just six years ago to the 90+ detections announced to date, this new messenger has provided a wealth of results across a variety of astrophysical disciplines. However, despite the oft-used analogy of gravitational waves opening a "new window" on the universe, we have yet to produce an actual image of an astronomical object using gravitational waves. This is in part due to the (nearly) all-sky sensitivity of GW interferometers, as well as the isolated point-source nature of the GW-emitting systems observed thus far. In addition to these point sources, the universe contains extended GW sources of astrophysical or perhaps cosmological origin that may be detectable with future GW observatories in various wavebands. In this talk, we use the concept of "Gravitational Wave Imaging" as a theme for considering the future of Gravitational Wave astronomy beyond the currently planned instruments on ground and in space. We ask the questions: What constitutes a GW Image? What science opportunities are enabled by making such images? What observing and measurement concepts are required to produce them?