Two College of Science physics faculty members were instrumental in a groundbreaking study honored by IOP Publishing as one of 2024’s most-cited articles in astronomy. Xavier Siemens and Jeff Hazboun are part of NANOGrav, the North American Nanohertz Observatory for Gravitational Waves, an international consortium of nearly 200 researchers who found compelling evidence for the existence of a “chorus” of low-frequency gravitational waves reverberating across the universe.
IOP Publishing recognized “The NANOGrav 15yr Data Set: Evidence for a Gravitational-wave Background” as among the top 1% of the most-cited astronomy and astrophysics articles published in their journals with corresponding authors based in North America. The paper was released in June 2023. IOP Publishing oversees more than 100 journals, around 100 books, as well as conference proceedings and magazines.
The gravitational waves, whose oscillations are measured in years and decades, were detected through a pulsar timing array — a network of precisely monitoring pulsars acting as cosmic clocks. A pulsar is a rapidly rotating neutron star that emits beams of radiation with extreme regularity. As these beams sweep across space, scientists use the beams to find subtle changes caused by gravitational waves. Detected waves are linked to supermassive black hole mergers, offering clues about the dynamic processes shaping galaxies. NANOGrav continues to expand its pulsar array, enhancing sensitivity for future discoveries.
