Sargent, Wallace Leslie William

Wallace “Wal” Sargent was one of the major figures of observational astronomy in the latter part of the twentieth century. Born and educated in Britain, he spent most of his life at Caltech in the USA. He made important contributions to the spectroscopic study of Ap stars, helium abundances in the universe, and the nuclei of Seyfert and elliptical galaxies. He pioneered the field of the astrophysics of the diffuse intergalactic medium and the chemical history of the universe through quasar absorption line spectroscopy.