By studying gravitational waves, we can gain new insights into the merging events between massive objects such as black holes as well as neutron stars. Moreover, studying low-frequency waves allows us to observe merging events between supermassive black holes at the centers of galaxies, which in turn allows us to learn about galaxy formation and structure. These gravitational waves are analogous to ripples caused by tossing a rock into a pond in that both are wave-like disturbances in some material, some medium. While a rock disturbs and displaces the water in a pond, merging events disturb and displace the fabric of the universe, known as spacetime. Laser interferometry is one approach to detecting gravitational waves, and facilities such as the Laser Interferometer Gravitational-Wave Observatory (LIGO) have used it successfully in that capacity. However, ground-based laser interferometry is unable to detect low-frequency (Around 10^-9 Hz) waves. A proposed detection method is to use a pulsar timing array (PTA), which involves monitoring a group of known pulsars and correlating any discrepancies in the arrival time of their radio pulses; we can do this because pulsars act as finely tuned clocks with their very consistent radio pulses. Ultimately, this method should allow us to detect low-frequency gravitational waves.

Ian Diaz is a senior in Physics. He is a member of NANOGrav and his research is supervised by Prof. Xavier Siemens.