Over the course of a half-century at Princeton, Ostriker’s research and discoveries, global collaborations, and teaching had resounding impact on the field of astrophysics and generations of students.
Astrophysicist Jeremiah P. Ostriker, pioneer of modern cosmology and ‘source of inspiration,’ dies at 87
Jeremiah “Jerry” P. Ostriker, the Charles A. Young Professor of Astronomy on the Class of 1897 Foundation, Emeritus, and professor of astrophysical sciences, emeritus, died at his home in New York City on April 6. He was 87.
Over the course of a half-century at Princeton, Ostriker’s research and discoveries, global collaborations, and mentorship and teaching had resounding impact on the field of astrophysics and generations of students. In 2000, President Bill Clinton awarded him the highest honor in the United States for a scientist, the National Medal of Science.
Ostriker joined Princeton’s faculty in 1966, transferred to emeritus status in 2012 and remained engaged in research until his death. From 1979 to 1995, he served as chair of the Department of Astrophysical Sciences and director of Princeton University Observatory. He served as provost under President Harold Shapiro from 1995 to 2001 — during which time he was instrumental in helping to shape the University’s grant-based financial aid program, which enables students to graduate debt-free. He later also served as director of the Princeton Institute for Computational Science and Engineering (PICSciE). After retiring from Princeton, he was professor of astronomy at Columbia University. Princeton awarded him an honorary degree in 2017.
The leap from “luminous” stars to dark matter
“Jerry Ostriker made important contributions in an astonishingly broad range of areas in astrophysics,” said Michael Strauss, professor of astrophysical sciences and department chair. “He developed much of our modern understanding of the halos of dark matter in which galaxies are embedded, and more generally, laid the framework for our modern models for how galaxies form.”
A pioneer in the field of cosmology — the science that probes the origin, development and structure of the universe — Ostriker is responsible for groundbreaking discoveries, beginning in the early 1970s, that forever changed the way astronomers think about what the universe is made of, including the existence of dark matter, the size and density of galaxies, and the dynamics of the gas between stars.
Prior to Ostriker’s work, most astronomers calculated the mass of galaxies based on visible or “luminous” stars in the galaxies. Ostriker’s research took a radically different approach.
In 1973, Ostriker — in collaboration with P. James Peebles, a Princeton colleague who went on to win the 2019 Nobel Prize in physics for his cosmology work — developed computer simulations that demonstrated that observed disk galaxies would be violently unstable without the presence of massive halos. They concluded in a 1974 paper with Amos Yahil (then a postdoctoral fellow at Princeton) that the mass of galaxies was 10 times larger than could be explained by ordinary matter. Ostriker and Peebles’ research probed the properties of halos of non-luminous “dark matter,” which we cannot see but which can be detected by its gravitational influence. Their papers ushered in the field of dark matter cosmology.
“Jerry's broad interests, his quick logical mind, and his energetic collaborations with students and colleagues resulted in great contributions to the advance of astronomy,” said Peebles, Princeton’s Albert Einstein Professor of Science, Emeritus, professor of physics, emeritus, and 1962 graduate alumnus. “I experienced all these traits when working with Jerry in establishing starting ideas about the dark matter that is required to understand astronomical observations. And it remains a fascinating puzzle for physicists to see how dark matter fits in their well-tested quantum theory of matter.”
Just three years after the 1973-74 breakthrough, in collaboration with Christopher McKee at the University of California-Berkeley, Ostriker produced a model that changed the way astronomers think of the interstellar medium, emphasizing the importance of a hot phase, created by supernova explosions, in the diffuse gas that fills the space between the stars.
Ostriker was born in 1937 and raised in Manhattan. His father was a businessman and his mother a schoolteacher. At Harvard, where he earned an A.B. in physics and chemistry, he also studied art, history and literature.
He and his wife, Alicia, an English major at Brandeis University who was also a high school classmate, married in 1958, during their senior year of college. He earned a Ph.D. in astrophysics at the University of Chicago in 1964, after which the couple held fellowships in Cambridge (England), coming to Princeton in 1965. Alicia became a prolific poet, critic and professor of English at Rutgers University.
An “enormously inventive” scientist who embraced discovery through collaboration
Throughout his illustrious career, Ostriker reached across departments and oceans to build collaborations that spurred innovation and discovery.
Ostriker was instrumental in building the worldwide collaboration of astronomers who carried out the Sloan Digital Sky Survey (SDSS) — a massive three-dimensional mapping of the universe that is widely considered to be one of the most successful projects in the history of astronomy and which, among many other things, helped to confirm the existence of dark energy. Early in his career he worked with several Japanese astronomers, notably Satoru Ikeuchi of Kyoto University, which led to the involvement of the Japanese astronomical community in SDSS, and subsequent collaborations on cosmological and planet imaging surveys with Japan's Subaru telescope.
“Jerry Ostriker was an enormously inventive and astute theoretical astrophysicist who made fundamental contributions across the whole field,” said James Gunn, the Eugene Higgins Professor of Astrophysical Sciences, Emeritus. Gunn worked closely with Ostriker over the years, including on SDSS — with Ostriker setting up the collaboration and support and Gunn designing and building much of the instrumentation, including the 700-pound camera built in Peyton Hall.
As much as they admired his brilliance, his Princeton colleagues in the Department of Astrophysical Sciences in Peyton Hall also remember Ostriker’s warm, welcoming spirit that created strong community, especially during his 16 years as department chair — and his deadpan sense of humor.
“He enjoyed life,” Gunn said. “He paid attention to everything that was going on and was always miles ahead of you. When we were designing the Sloan Survey, we held weekly lunch meetings with lots of food. Jerry would come by as we were winding up, looking for interesting food and saying things like: ‘Haven't you got this figured out YET?! I came up with five different universes just this morning!’”
“Jerry was a very smart and sharp person, and also extremely fair and kind. We all had and have the good fortune of working in a supportive and constructive academic environment with very high standards,” said Jill Knapp, emerita professor of astrophysics. “As department chair, he played a pivotal role in broadening the representation of all people across the astrophysics department. This took courage and smarts, and we are all lucky that he had an abundance of both.”
A “consummate doer” who loved to solve problems, day and night
Ostriker’s daughter, Eve Ostriker, the Lyman Spitzer, Jr. Professor of Theoretical Astrophysics and professor of astrophysical sciences, joined Princeton’s faculty in 2012. Growing up, she said it was experiencing the sense of play her father brought to his work and how much fun he seemed to be having that inspired her. Throughout his life, she witnessed his love of seeking solutions by collaborating with others — whether undergraduates or world-renowned scientists.
“The three great loves of my father’s life were the universe, his family and Princeton University, in some unspecified order,” she said. “His character in his prime was irreverent, funny and full of life. He was a consummate doer. Whether figuring out what physics governs the origin and evolution of galaxies, how to make Princeton accessible to students from all economic backgrounds, or the optimal way to construct a sauna from stacked two-by-fours, what he liked best was solving problems.”
She said the first thing her father would do after a family trip — no matter what time of day or night they arrived home — was hop on his bike and cycle to Peyton Hall.
“There, he would meet with his students to catch up on their progress and discuss ideas for next steps,” she said. “His devotion to science, to the institutions of which he was a part, and to all of the people he was connected to, stand as an inspiration for all of us.”
Remembering a mentor and “a true example of a lifetime pursuit of truth”
Ostriker mentored generations of graduate students and postdoctoral fellows, many of whom have gone on to prestigious careers in the field. More than one of his former advisees later became colleagues.
Scott Tremaine, a 1975 graduate alumnus, was recruited two decades later by Ostriker and taught at Princeton from 1997 to 2007.
“Jerry taught me how to do research and taught me most of what I know about galaxies and stellar dynamics,” said Tremaine, professor emeritus at the Institute for Advanced Study. “He was remarkable for his energy, for his wise advice, for his rhetorical skills and for his ingenious good humor.”
Renyue Cen, a senior research astronomer at Princeton from 2000 to 2022 who has collaborated and co-authored with Ostriker, earned his Ph.D. in 1990 and considers himself “extremely lucky” to have had Ostriker as his adviser.
“He spent countless weekends guiding me through the thicket of physics and astrophysics and sharing an endless flow of ideas, many of which I was only able to appreciate years later,” said Cen, who holds chair professorships at both the Institute for Advanced Study in Physics and the School of Physics at Zhejiang University.
Cen had planned to visit Ostriker this summer to bring him “the equivalent in Chinese literature of [geneticist] David Reich’s ‘Who We Are and How We Got Here,’ per Jerry’s request. He was a true example of a lifetime pursuit of truth.”
Kentaro Nagamine, a full professor at the University of Osaka, earned his Ph.D. in 2001. Ostriker, then provost, still made time to meet with Nagamine on Saturday afternoons in Peyton Hall.
“I vividly remember one occasion when he came by in a relaxed mood, wearing jeans with dirt on his knees. I asked what had happened, and he smiled and said he’d been working in his garden. That moment captured his essence — always down to earth, warm, supportive, and full of energy and ideas that could help you break through whatever obstacle you were facing,” Nagamine said.
He later visited Ostriker at Cambridge when Ostriker was the Plumian Professor of Astronomy at the University of Cambridge (2001-04), and witnessed how his former adviser was quickly surrounded by British professors at a formal dinner banquet. “I couldn’t even get close — I just watched from behind,” he said. “That too reflected his charm and wit, which extended far beyond the U.S. — it was truly global.” Recently, when Nagamine shared the news of Ostriker’s death with the Astronomical Society of Japan’s email list, several colleagues posted remembrances, a testament to his international collaborations.
While provost, Ostriker also advised Ue-Li Pen, even though that often meant having their weekly meetings at 3 a.m. due to Pen’s night schedule related to his studies.
“Jerry was a unique source of inspiration and a role model,” said Pen, who earned his Ph.D. in 1996 and is the director of the Academia Sinica Institute for Astronomy and Astrophysics in Taipei, and professor at the Canadian Institute for Theoretical Astrophysics at the University of Toronto. “He was always open to new ideas.”
Just days after Ostriker’s death, Ellen Zweibel, the W. L. Kraushaar Professor of Astronomy and Physics at the University of Wisconsin-Madison who earned her Ph.D. in 1977, gave a tribute to her adviser during her graduate class on astrophysical dynamics. “I introduced the phrase ‘parameterizing our ignorance,’ which I heard first from him, and the concept of plotting ‘x versus x,’ which he first muttered to me when we were sitting together at a conference talk.”
She said: “Jerry had a unique way of making abstractions vivid without obscuring their essential qualities. He lived and breathed high standards, whether in the classroom or as a mentor, that I always aspired to live up to.”
Ostriker’s many honors and awards include the American Astronomical Society’s Warner Prize and Russell Lectureship and the Royal Astronomical Society’s Gold Medal. He was a member of and served on astronomy and astrophysics committees for the American Astronomical Society, National Academy of Sciences, International Astronomical Union, American Academy of Arts and Sciences, American Philosophical Society, Royal Netherlands Academy of Arts and Sciences and Royal Astronomical Society of London.
Ostriker is survived by his wife, Alicia Ostriker; daughters Rebecca Ostriker (Ian MacKinnon) and Eve Ostriker (Nat Bottigheimer), and son Gabriel Ostriker (Allison Ostriker); three grandchildren, Abigail Ostriker, Naomi Ostriker and Rosalind Ostriker; and his sister Naomi Seligman and brothers Jon Ostriker and David Ostriker.
Donations to honor Ostriker may be made to Friends of Princeton Open Space.
View or share comments on a memorial page intended to honor Ostriker's life and legacy.