Japanese Nobel laureate Masatoshi Koshiba, a pioneer in the field of astrophysics, died late on Thursday at a hospital in Tokyo, AP reported. He was 94.

The announcement of Koshiba’s death was made by the University of Tokyo, where he was a distinguished professor. The university, however, did not reveal the cause of death.

Koshiba won the Nobel Prize in Physics in 2002 for the discovery of elementary particles called neutrinos, along with American chemist Raymond Davis Jr and American-Italian astrophysicist Riccardo Giacconi.

The Nobel laureate’s work served as a foundation for other researchers. Takaaki Kajita, one of Koshiba’s students, went on to win the Nobel Prize in physics in 2015 “for the discovery of neutrino oscillations, which shows that neutrinos have mass”.

Koshiba played an active role in providing science education to young people, according to AP. With his Nobel award, he established a science foundation for high school and college students.

Koshiba was born in Toyohashi in Japan’s Aichi Prefecture, according to the Nobel Prize website. He studied at the University of Tokyo and went on to get his PhD from the University of Rochester in New York in 1955.

He worked at the University of Chicago for several years and then returned to Japan. He conducted his Nobel-winning research in Tokyo.