Astronomer Sandra Faber awarded Gruber Cosmology Prize

Faber's groundbreaking studies of galaxies helped establish many of the foundational principles of modern cosmology

Sandra Faber

The Gruber Foundation will award the 2017 Gruber Cosmology Prize to Sandra Faber, professor emerita of astronomy and astrophysics at UC Santa Cruz. The $500,000 prize recognizes Faber for a body of work that has helped establish many of the foundational principles underlying the modern understanding of the universe on the largest scales.

Faber, who received the National Medal of Science in 2013, is renowned for her contributions to the understanding of dark matter, galaxy formation, and the large-scale structure of the universe. She will receive the Gruber Prize at an award ceremony this fall.

The award citation praises Faber for "her groundbreaking studies of the structure, dynamics, and evolution of galaxies." That work has led to the widespread acceptance of the need to study dark matter, to an appreciation of the inextricable relationship between the presence of dark matter and the formation of galaxies, and to the recognition that black holes reside at the heart of most large galaxies. She has also made significant contributions to the innovations in telescope technology that have revolutionized modern astronomy. Through these myriad achievements, the Gruber citation adds, Faber has "aided and inspired the work of astronomers and cosmologists worldwide."

A partial summary of her achievements includes:

  • In 1976, Faber and Robert Earl Jackson discovered a relation between the orbital speeds of stars in elliptical galaxies and the galaxy's mass. Other such laws have emerged since then, but the Faber-Jackson relation was the first.
  • In 1979, Faber and John S. Gallagher published a paper that provided a comprehensive review of the evidence for the existence of dark matter. Among astronomers this paper is regarded as the turning point in the debate about whether 80 percent of the mass in the universe is "missing"—mysterious, invisible, and impervious to direct detection.
  • Faber’s discovery of large amounts of dark matter (using indirect methods of detection) in a certain exotic species of galaxy led her to conclude, in a 1983 paper with UCSC astronomer Douglas Lin, that dark matter could not be neutrinos, a subatomic particle that travels close to the speed of light ("hot," in cosmological parlance), but might be another species of subatomic particle, not yet known, that travels at a much slower rate ("cold").
  • The following year Faber was part of a four-member collaboration that presented a comprehensive theory of how cold dark matter could explain the structure and behavior of galaxies and superclusters of galaxies that we actually observe in the universe. This theory remains the paradigm underpinning all modern models of galaxy formation. Her coauthors were George Blumenthal, now UCSC's chancellor; UCSC physicist Joel Primack; and U.K. Astronomer Royal Martin Rees.
  • In 1985, Faber emerged as the leading science advocate for the construction of the 10-meter Keck telescope in Hawaii (the most powerful on the planet when it went online in 1993) and, with UCSC astronomer Harland Epps, developed the optical design. (UCSC astronomers Jerry Nelson and Terry Mast also made important contributions to the Keck telescope design.) Faber later served as the co-chair of the Keck Science Steering Committee and went on to lead construction of the DEIMOS spectrograph on Keck, one of the largest and most innovative astronomical instruments in the world.
  • During that same period Faber was a member of the collaboration developing the Wide-Field Camera for the Hubble Space Telescope. (She may have been the only astronomer to play a major role on both Keck and Hubble.) After the launch of the telescope a few years later, she and postdoc Jon Holtzman diagnosed the spherical aberration that was compromising the telescope’s image quality. Faber then led the replanning of the entire suite of early observations.
  • In 1988, Faber was the principal investigator among the so-called Seven Samurai, a collaboration that discovered irregularities in the rate of the universe’s expansion that apparently depend on the distribution of matter, and therefore the distribution of gravitational effects, on the largest scales.
  • From 1985 to 2002, Faber served as the principal investigator for a collaboration that came to call themselves the "Nukers"—because they were studying the nuclei of galaxies. Among the discoveries that the Nuker collaboration made under Faber's leadership were that the center of every large galaxy harbors a massive black hole and that the mass of that central black hole closely correlates to the orbital speed of stars within the galaxy as a whole.
  • Since 2010, Faber has served as co-principal investigator, with Henry Ferguson, on the CANDELS (Cosmic Assembly Near-infrared Deep Extragalactic Survey) collaboration, the largest project in the history of the Hubble Space Telescope. Over the course of more than 900 Earth orbits, the team collected data on the most distant, and therefore (because the light from the galaxies takes billions of years to reach us) among the youngest, galaxies. By comparing those data with the already existing voluminous data about galaxies near to us, astronomers can trace the evolution of galaxies throughout cosmic time.

As a body of work, these advances and discoveries, both observational and technological, have helped define how scientists think about and investigate galaxies and superclusters of galaxies, the largest structures in the universe.

For Faber, though, they have also helped define how civilization can conceive of its place in the cosmos. In recent years she has become a prolific public speaker, providing a cosmic perspective on our planet and urging audiences to consider humanity's "custodial responsibility" for the Earth, which she calls "a jewel of the universe."

Faber joined the faculty at UC Santa Cruz in 1972 and in 1995 was made University Professor, the highest honor for faculty in the UC system. A member of the National Academy of Sciences, American Academy of Arts and Sciences, and American Philosophical Society, she has received many awards and honors in recognition of her accomplishments. She earned her bachelor's degree in physics at Swarthmore College and her Ph.D. in astronomy at Harvard University.

The Yale-based Gruber International Prize Program annually honors individuals in the fields of cosmology, genetics, and neuroscience for groundbreaking work that inspires and enables fundamental shifts in knowledge and culture.