2007 Gruber Cosmology Prize

Saul Perlmutter and Brian Schmidt and their teams: the Supernova Cosmology Project and the High-z Supernova Search Team, discovered that the expansion of the Universe is accelerating.

An accelerating universe was a crazy result that was hard to accept. Yet, two teams, racing neck and neck, simultaneously came to the same conclusion. Their discovery led to the idea of an expansion force, dubbed dark energy. And it suggests that the fate of the universe is to just keep expanding, faster and faster.

The two teams expected to find that the universe would either expand then contract, or it would expand for ever but slowing over the millennia. But there were a growing number of hints that all was not right with the theories of the time.

To find out, they not only needed to be able to measure the speed with which distant objects are traveling away from us, but also how far away they are. And to do this they needed standardized light sources — very bright ones that would be visible to Earth-based telescopes despite being billions of light years away and billions of years old.

The standard light sources they used were exploding stars — in particular Type Ia supernovae. But finding them wasn’t easy. Then the analyses over the results turned up very surprising results. “The data wasn’t behaving as we thought it would,” says Schmidt. “There was a lot of nervous laughter,” says Perlmutter. For both teams it was not what they were expecting. For months they both tried to figure out where they had gone wrong, searching for any tiny source of error. But the data was right. The accepted model of the universe was wrong.

Today Perlmutter, Schmidt and their colleagues continue to explore the implications of their work. Schmidt is planning the SkyMapper project, a telescope to map the southern sky. Perlmutter is working on a satellite mission that would study supernovae and the nature of dark energy.

The $US500,000 prize will be shared in four parts: by Schmidt — at the Australian National University; Saul Perlmutter — at the University of California, Berkeley; and the fifty-one co-authors of the key papers.

Saul Perlmutter and the Supernova Cosmology Project Team from Australia, Chile, France, Spain, Sweden, UK and USA.

1. Gregory Aldering, Lawrence Berkeley National Laboratory
2. Brian J. Boyle, Australia Telescope National Facility
3. Patricia G. Castro, Instituto Superior Técnico, Lisbon
4. Warrick Couch, Swinburne University of Technology
5. Susana Deustua, American Astronomical Society
6. Richard Ellis, California Institute of Technology
7. Sebastien Fabbro, Instituto Superior Técnico, Lisbon
8. Alexei Filippenko, University of California, Berkeley (also a member of the High-z team)
9. Andrew Fruchter, Space Telescope Science Institute
10. Gerson Goldhaber, Lawrence Berkeley National Laboratory
11. Ariel Goobar, University of Stockholm
12. Donald Groom, Lawrence Berkeley National Laboratory
13. Isobel Hook, University of Oxford
14. Mike Irwin, University of Cambridge
15. Alex Kim, Lawrence Berkeley National Laboratory
16. Matthew Kim
17. Robert Knop, Vanderbilt University
18. Julia C. Lee, Harvard University
19. Chris Lidman, European Southern Observatory
20. Richard McMahon, University of Cambridge
21. Thomas Matheson, NOAO Gemini Science Center
22. Heidi Newberg, Rensselaer Polytechnic Institute
23. Peter Nugent, Lawrence Berkeley National Laboratory
24. Nelson Nunes, University of Cambridge
25. Reynald Pain, CNRS-IN2P3, Paris
26. Nino Panagia, Space Telescope Science Institute
27. Carl Pennypacker, University of California, Berkeley
28. Robert Quimby, The University of Texas
29. Pilar Ruiz-Lapuente, University of Barcelona
30. Brad Schaefer, Louisiana State University
31. Nicholas Walton, University of Cambridge

And for the High-z Supernova Search Team: Brian Schmidt and his team from the USA, UK, Germany, Chile and Australia,

1. Peter Challis, Harvard University
2. Alejandro Clocchiatti, Pontificia Universidad Católica de Chile
3. Alan Diercks, Institute for Systems Biology, Seattle
4. Alexei V. Filippenko, University of California, Berkeley
5. Peter M. Garnavich, University of Notre Dame
6. Ronald L. Gilliland, Space Telescope Science Institute
7. Craig J. Hogan, University of Washington
8. Saurabh Jha, Stanford Linear Accelerator Center
9. Robert P. Kirshner, Harvard University
10. Bruno Leibundgut, European Southern Observatory
11. Mark M. Phillips, Carnegie Observatories
12. David Reiss, Institute for Systems Biology. Seattle
13. Adam G. Riess, the Johns Hopkins University
14. Robert A. Schommer (Deceased)
15. R. Chris Smith, Cerro Tololo Inter-American Observatory, Chile
16. Jason Spyromilio, European Southern Observatory
17. Christopher Stubbs, Harvard University
18. Nicholas B. Suntzeff, Texas A&M University
19. John L. Tonry, Institute for Astronomy, Honolulu

The key papers reporting their discoveries were Riess et al., 1998, AJ, 116, 1009, "Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant"

http://www.journals.uchicago.edu/AJ/journal/issues/v116n3/980111/980111....

Perlmutter et al. 1999, ApJ, 517, 565, "Measurements of Omega and Lambda from 42 High-Redshift Supernovae"

http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v517n2/39148/391...