Mapping the Host Galaxies of Nanohertz Gravitational Wave Sources

Supermassive black hole binaries (SMBHBs) present us with exciting opportunities for multi-messenger science. These binaries are thought to form as a natural consequence of galaxy mergers, with the potential to produce bright electromagnetic (EM) emission as well as individually resolvable gravitational waves (GWs) that can be detected with pulsar timing arrays (PTAs). We may find SMBHBs in a wide variety of systems, and each type of system may generate a distinct EM signature, or none at all. This makes direct multi-messenger searches challenging, but the answer could lie in our ability to identify the galaxy hosting the SMBHB. In this talk, I will show how we can connect PTA observations with large galaxy catalogs to optimize host galaxy identification following the first detection of a single-source GW signal. I will discuss how this approach has the potential to accelerate the first multi-messenger observations of a SMBHB.