NASA has named professor of astronomy and physics Priyamvada Natarajan to its team of U.S. scientists lending expertise on gravitational waves and astrophysics for the upcoming LISA mission.
LISA — which stands for Laser Interferometer Space Antenna — is a space-based, gravitational wave observatory that will be composed of three spacecraft separated by millions of miles. The mission, scheduled for the early 2030s, is a collaboration between NASA, the European Space Agency, and the LISA consortium. Natarajan is a member of the NASA LISA Study Team.
“The detection of gravitational waves in 2015 by the LIGO (Laser Interferometer Gravitational-Wave Observatory) collaboration is one of the major scientific breakthroughs of this century,” Natarajan said. “The tremors they identified in space-time, produced by the collision of two stellar-mass black holes, was extremely challenging to detect. The more massive cousins of these black holes are supermassive black holes that reside in the centers of most, if not all, galaxies.”
Supermassive black holes also are likely to have been built up via mergers, Natarajan explained. “The cosmic earthquakes produced during these collisions cannot be detected from the Earth and require a LIGO-like interferometer in space as these events will be detectable at much lower frequencies,” she said. “The LISA mission plans to detect these gravitational waves from space-based detectors. The mission will test our fundamental understanding of how supermassive black holes form and grow.”
Natarajan’s research focuses on understanding the formation of the first black holes and the accumulation of mass in the most massive black holes in the universe.
“We currently believe that black holes grow both via direct consumption of gas and stars in their vicinity, as well as via mergers with other black holes,” Natarajan said. “The detection of gravitational waves from colliding supermassive black holes by LISA would validate and calibrate the relative importance of mergers versus accretion.”
Natarajan’s research into black holes also figures prominently in the Jan. 10 episode of the PBS science documentary series, “NOVA.” The episode, “Black Hole Apocalypse,” features portions of an interview with Natarajan and is set for 9 p.m.
“My research group at Yale is extremely active and we are working at the leading edge of these questions combining theoretical models, numerical simulations, and the most up-to-date multi-wavelength observations,” Natarajan said.