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Keck astronomer wins Gruber Prize for Cosmology


Charles Steidel, the Lee A. DuBridge Professor of Astronomy at the California Institute of Technology, is the recipient of the 2010 Cosmology Prize of The Peter and Patricia Gruber Foundation. The award recognizes Steidel’s revolutionary studies using the W. M. Keck Observatory of the most distant galaxies in the Universe.

“Professor Steidel pioneered the techniques needed to find young galaxies and led the efforts that have opened a direct observational window to a time when the Universe was only about one tenth of its current age,” the official citation said.

Charles Steidel, the Lee A. DuBridge Professor of Astronomy at the California Institute of Technology, is the recipient of the 2010 Cosmology Prize of the Peter and Patricia Gruber Foundation in recognition of his revolutionary studies using Keck Observatory of the most distant galaxies in the Universe. (Photo courtesy of California Institute of Technology)

Steidel will receive the $500,000 award, as well as a gold medal, in October at the University of Chicago in Chicago, Illinois, where he will also deliver a lecture.

“My main scientific interest is, and has been, how did the first galaxies form? When did they form and has the way that galaxies form changed over time?” Steidel said.

In order to answer those questions, he and his colleagues needed to observe galaxies at different stages of the Universe’s history. The astronomers were especially interested in so-called “primordial galaxies,” which date from a period of more than 12 billion years ago, when the Universe was less than two billion years old.

Astronomers had already observed a handful of objects at such a distance, but most were extreme, such as quasars and not normal, star-forming galaxies. Steidel realized, however, that stars, and therefore galaxies, are rich in hydrogen.

Hydrogen absorbs radiation with wavelengths shorter than 91.2 nanometers — what astronomers call the Lyman limit. As a result, galaxies are mostly invisible below the Lyman limit, in the far ultraviolet region of the electromagnetic spectrum, but visible above it.

Although light with a wavelength of 91.2 nanometers is not accessible on Earth due to the interference of the atmosphere, Steidel and his colleagues knew that the expansion of the Universe would stretch the length of the waves until they were visible.

And, they knew a wave of light with a length of 91.2 nanometers that traveled 12 billion lightyears would have stretched to wavelengths observable with ground-based telescopes. If they could observe these distant objects and detect a sharp cutoff, or break, at that wavelength, they would know the objects were galaxies.

After outlining their approach in papers now considered classics, Steidel and his colleagues discovered their first batch of distant galaxies, called Lyman Break Galaxies, in October 1995, using the Keck I telescope and its Low Resolution Imaging Spectrograph.

“My entire scientific focus came to be during my first nights on the Keck telescope in 1995. Ever since then, I think of Keck as an extension of where I work, almost like an extended family,” Steidel said.

His team’s observations using his new technique were the first to show that galaxies were common, even at such an early point in the Universe’s evolution.

“Using Keck, Chuck Steidel has revolutionized our understanding of how galaxies in the early Universe form and change over cosmological time. His work is very deserving of this prestigious award,” said Taft Armandroff, the director of the W. M. Keck Observatory.

Steidel’s award is the second Gruber Prize for Cosmology given to an astronomer whose scientific discoveries were made using data taken with the Keck telescopes.

In 2007, two teams led by Saul Perlmutter and Brian Schmidt, respectively, received the award to recognize their observations revealing that the expansion of the Universe is accelerating. Their discovery led to the idea of an expansion force, called dark energy.

In the past five years, Steidel has extended his study of galaxy formation by moving somewhat forward in time, to the period about 10 to 12 billion years ago — a peak era for star formation, supernova explosions, and the accumulation of gas by supermassive black holes.

This year he is publishing his first paper about a new technique that uses multiple “skewers” of one-dimensional views through the Universe to create a composite 3-D view of these highly active galaxies spewing gas into intergalactic space.

Using this method, Steidel and his team have discovered that a galaxy can influence a region in space one hundred times the diameter of the galaxy itself.

“How do you efficiently find lots and lots of galaxies wherever you want at a particular point in the sky at a particular distance in order to isolate a particular period in the history of the Universe?” Steidel said.

Over the last 20 years, he has provided many of the answers, and his work has helped expand cosmology from the study of the evolution of the Universe as a whole to the study of cosmic evolution of its parts—galaxies.

The W. M. Keck Observatory operates two 10-meter optical/infrared telescopes on the summit of Mauna Kea on the island of Hawaii and is a scientific partnership of the California Institute of Technology, the University of California, and NASA.

The Peter and Patricia Gruber Foundation honors and encourages educational excellence, social justice and scientific achievements that better the human condition.

The official citation

The Peter and Patricia Gruber Foundation proudly presents the 2010 Cosmology Prize to Charles Steidel for his groundbreaking studies of the distant Universe.

Professor Steidel pioneered the techniques needed to find young galaxies and led the efforts that have opened a direct observational window to a time when the Universe was only about one tenth of its current age.

This breakthrough has allowed us to witness first-hand the dramatic transformation galaxies undergo throughout their lives, and has revolutionized, challenged, and inspired our current understanding of how structures form and evolve in the Universe.

Laureates of the Gruber Cosmology Prize

2009: Wendy Freedman, Robert Kennicutt and Jeremy Mould for the definitive measurement of the rate of expansion of the universe, Hubble’s Constant

2008: J. Richard Bond for his pioneering contributions to our understanding of the development of structures in the universe

2007: Saul Perlmutter and Brian Schmidt and their teams: the Supernova Cosmology Project and the High-z Supernova Search Team, for independently discovering that the expansion of the universe is accelerating

2006: John Mather and the Cosmic Background Explorer (COBE) Team for studies confirming that our universe was born in a hot Big Bang

2005: James E. Gunn for leading the design of a silicon-based camera for the Hubble Space Telescope and developing the original concept for the Sloan Digital Sky Survey

2004: Alan Guth and Andrei Linde for their roles in developing and refining the theory of cosmic inflation

2003: Rashid Alievich Sunyaev for his pioneering work on the nature of the cosmic microwave background and its interaction with intervening matter

2002: Vera Rubin for discovering that much of the universe is unseen dark matter, through her studies of the rotation of spiral galaxies

2001: Martin Rees for his extraordinary intuition in unraveling the complexities of the universe

2000: Allan R. Sandage and Phillip J. E. (Jim) Peebles: Sandage for pursuing the true values of the Hubble constant, the deceleration parameter and the age of the universe; Peebles for advancing our understanding of how energy and matter formed the rich patterns of galaxies observed today

The Prize recipients are chosen by the Cosmology Selection Advisory Board. Its members are: Jacqueline Bergeron, Institut d’Astrophysique-CNRS; Wendy Freedman, The Observatories of the Carnegie Institution of Washington; Peter Galison, Harvard University; Ronald Ekers, Australia Telescope National Facility – CSIRO; Andrei Linde, Stanford University; Julio F. Navarro, University of Victoria; and Roger Penrose, University of Oxford. Owen Gingerich of the Harvard-Smithsonian Center for Astrophysics, and Virginia Trimble of the University of California, Irvine, also serve as special Cosmology advisors to the Foundation.

The Gruber Prize Program honors contemporary individuals in the fields of Cosmology, Genetics, Neuroscience, Justice and Women’s Rights, whose groundbreaking work provides new models that inspire and enable fundamental shifts in knowledge and culture.

The Selection Advisory Boards choose individuals whose contributions in their respective fields advance our knowledge, potentially have a profound impact on our lives, and, in the case of the Justice and Women’s Rights Prizes, demonstrate courage and commitment in the face of significant obstacles.

In 2000, The Peter and Patricia Gruber Foundation and the International Astronomical Union (IAU) announced an agreement by which the IAU provides its expertise and contacts with professional astronomers worldwide for the nomination and selection of Cosmology Prize winners.

Under the agreement, The Peter and Patricia Gruber Foundation also funds a fellowship program for young astronomers, with the aim of promoting the continued recruitment of new talent into the field.

The International Astronomical Union, founded in 1919, is an organization of professional astronomers. It serves today a membership of more than 9,000 individual astronomers from 85 countries, worldwide.

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One Response to “Keck astronomer wins Gruber Prize for Cosmology”

  1. Sally says:

    Yay this guy is so amazing he totally deserves it


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