Maarten Schmidt, Francis L. Moseley Professor of Astronomy, Emeritus, at Caltech, passed away on Saturday, September 17, 2022. He was 92 years old. Schmidt is well known for his 1963 discovery of quasars—extremely bright and distant cosmic objects powered by active supermassive black holes.
Schmidt was born in December of 1929, in Groningen, the Netherlands. He earned his bachelor's and master's degrees from the University of Groningen, a PhD from Leiden University in 1956, and a Doctor of Science degree from Yale in 1966.
After earning his PhD, Schmidt did postdoctoral work at the Mount Wilson and Mount Palomar observatories for two years as a Carnegie Fellow. He then returned to the University of Leiden for one year before moving to the United States.
Schmidt joined Caltech in 1959 as an associate professor of astronomy. He became full professor in 1964, Institute Professor in 1981, and Moseley Professor in 1987. He retired and became Moseley Professor, Emeritus, in 1996. He had also served as the executive officer for astronomy from 1972 to 1975, chair of the Division of Physics, Mathematics and Astronomy from 1976 to 1978, and director of the Hale Observatories from 1978 to 1980.
After first coming to Caltech, Schmidt focused on mass distribution and dynamics of galaxies. During this period, he published a paper titled "The Rate of Star Formation," in which he outlined a relationship between gas density and star formation rate in a given region. This relationship came to be known as the Schmidt law.
Schmidt is best known for his discovery of quasars and his measurement of their great distances from Earth. While studying the light spectra of radio sources, he noticed that a cosmic object called 3C 273 produced spectral lines that had been shifted to the red end of the spectrum, or "red shifted," indicating that the object was roughly 3 billion light-years away, well outside our galaxy. Because the faraway object shone too brightly to be a star, Schmidt came to the realization that the "quasi-stellar object" was the core of a forming galaxy, in which swirling disks of matter surround a supermassive black hole.
Since this pivotal observation in 1963, thousands of quasars have been identified. These objects were more common in the early universe and are visible from Earth today because of the time it takes for light to travel over such enormous distances. Schmidt's work gave astronomers a deep insight into the history of our universe.
Schmidt is the recipient of numerous awards and honors, including the Kavli Prize for Astrophysics (2008); the Bruce Medal (1992); the James Craig Watson Medal (1991); the Gold Medal of the Royal Astronomical Society (1980); the Henry Norris Russel Lectureship (1978); and the Helen B. Warner Prize (1964). He was also on the cover of Time magazine on March 11, 1966.
He is survived by his three daughters: Anne, Marijke, and Elizabeth.
A full obituary will follow at a later date.