From Pulsar Timing to Gravitational Wave Detection with NANOGrav

Pulsar timing arrays have enabled our ability to detect nanohertz gravitational waves through precise measurements of millisecond pulsars over two decades. This talk provides a comprehensive overview of NANOGrav's efforts, from pulsar discovery and precision timing to noise modeling and eventual gravitational wave detection. I will discuss how characterization proceeds by considering both astrophysical sources (like supermassive black hole binaries) and potential cosmological sources. In 2023, NANOGrav and other pulsar timing arrays around the world announced evidence for a stochastic gravitational wave background. With this detection, these groups are now pursuing the next challenge: further exploring the background through searches for anisotropy and identifying single sources of gravitational waves. The talk concludes with my own work analytically deriving our sensitivity to anisotropic gravitational wave backgrounds, which will prove useful in our next steps towards characterizing this gravitational wave background.