Arp, Halton Christian (1927–2013)
American astronomer noted for challenging the theory that
the large redshifts of quasars and other active galaxies are an indication of great distance. His Atlas
of Peculiar Galaxies, published in 1966, contains photographs of 338
peculiar and interacting galaxies taken with the Hale
Telescope, and was instrumental in raising the issue of discordant
redshifts. Arp received a B.S. from Harvard (1949) and a Ph.D. from
the California Institute of Technology (1953).