FOCAL POINTS: Dark Energy Camera Records First Light

Eight billion years ago, rays of light from distant galaxies began their long journey to Earth. That ancient starlight has now found its way to a mountaintop in Chile, where the newly constructed Dark Energy Camera, the most powerful sky-mapping machine ever created, has captured and recorded it for the first time.

That light may hold within it the answer to one of the biggest mysteries in physics — why the expansion of the universe is speeding up.

Scientists in the international Dark Energy Survey (DES) collaboration, which includes astronomers from Texas A&M University, announced this week that the Dark Energy Camera, the product of eight years of planning and construction by scientists, engineers and technicians on three continents, has achieved first light. The first pictures of the southern sky were taken by the 570-megapixel camera on Sept. 12.

“The achievement of first light through the Dark Energy Camera begins a significant new era in our exploration of the Cosmic Frontier,” said James Siegrist, United States Department of Energy (DOE) associate director of science for high-energy physics. “The results of this survey will bring us closer to understanding the mystery of dark energy and what it means for the universe.”

The Dark Energy Camera was constructed at the DOE’s Fermi National Accelerator Laboratory (Fermilab) in Batavia, Ill., and mounted on the Victor M. Blanco telescope at the National Science Foundation’s Cerro Tololo Inter-American Observatory in Chile, which is the southern branch of the U.S. National Optical Astronomy Observatory (NOAO). Texas A&M astronomer Darren DePoy serves as the project scientist for the device — roughly the size of a phone booth — that will enable astronomers and physicists to probe the mystery of dark energy, the force they believe is causing the universe to expand faster and faster.

“The project to design, build, test and deploy the DECam has taken many years, and it was exciting to see the instrument take pictures of the sky,” said DePoy, who traveled to Chile for the groundbreaking first snap. “I was present in the telescope control room while the first images were obtained. The instrument had been installed on the telescope only a short time before, and it produced science-quality images very quickly. This is a testament to the hard work, expertise and enthusiasm of the large group of scientists, engineers and technicians who worked on the telescope and instrument over the past many years.”

A key sub-component of the camera — a spectrophotometric calibration system known as DECal that will allow the camera to obtain very high precision brightness measurements of the objects it sees in the sky — was built within Texas A&M’s Charles R. ’62 and Judith G. Munnerlyn Astronomical Laboratory, directed by DePoy.

“The Dark Energy Survey will help us understand why the expansion of the universe is accelerating, rather than slowing due to gravity,” said Brenna Flaugher, project manager and scientist at Fermilab. “It is extremely satisfying to see the efforts of all the people involved in this project finally come together.”

The Dark Energy Camera is the most powerful survey instrument of its kind, able to see light from more than 100,000 galaxies up to 8 billion light years away in each snapshot. The camera’s array of 62 charged-coupled devices has an unprecedented sensitivity to very red light, and along with the Blanco telescope’s large light-gathering mirror (which spans 13 feet across), will allow scientists from around the world to pursue investigations ranging from studies of asteroids in our own solar system to the understanding of the origins and the fate of the universe.

“We’re very excited to bring the Dark Energy Camera online and make it available for the astronomical community through NOAO’s open-access telescope allocation,” said Chris Smith, director of the Cerro-Tololo Inter-American Observatory. “With it, we provide astronomers from all over the world a powerful new tool to explore the outstanding questions of our time, perhaps the most pressing of which is the nature of dark energy.”

Scientists in the Dark Energy Survey collaboration will use the new camera to carry out the largest galaxy survey ever undertaken, and will use that data to carry out four probes of dark energy, studying galaxy clusters, supernovae, the large-scale clumping of galaxies and weak gravitational lensing. This will be the first time all four of these methods will be possible in a single experiment.

“We expect DECam will have a long and productive life on the telescope,” DePoy said. “The combination represents a new capability available to the entire astronomical community, one that can produce unprecedented science. We’re excited that Texas A&M Astronomy is part of such a groundbreaking project.”

The Dark Energy Survey is expected to begin in December, after the camera is fully tested, and will take advantage of the excellent atmospheric conditions in the Chilean Andes to deliver pictures with the sharpest resolution seen in such a wide-field astronomy survey. In just its first few nights of testing, the camera has already delivered images with excellent and nearly uniform spatial resolution.

Over five years, the survey will create detailed color images of one-eighth of the sky, or 5,000 square degrees, to discover and measure 300 million galaxies, 100,000 galaxy clusters and 4,000 supernovae.

The Dark Energy Survey is supported by funding from the U.S. Department of Energy; the National Science Foundation; funding agencies in the United Kingdom, Spain, Brazil, Germany and Switzerland; and the participating DES institutions, including Texas A&M University.

Click here to see the first images captured by the Dark Energy Camera.

For more information about the instrument and telescope, go to http://www.ctio.noao.edu.

For more information about the Dark Energy Survey, including the list of participating institutions,visit the project website at www.darkenergysurvey.org.

For a summary of the major components contributed to the Dark Energy Camera by the participating institutions, read this symmetry article.

To learn more about Texas A&M Astronomy, the Dark Energy Camera, the Large Synoptic Survey Telescope and other major international projects involving Texas A&M astronomers, visit Astronomy Research Page.

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About Research at Texas A&M University: As one of the world’s premier research institutions, Texas A&M is a leader in making significant contributions to the storehouse of knowledge in many fields, including rigorous scientific and technological disciplines. Research conducted at Texas A&M represents an annual investment of more than $700 million; the university ranks 20th among all U.S. universities and third nationally for universities without a medical school, according to the National Science Foundation. Research at Texas A&M creates new knowledge that provides basic, fundamental and applied contributions resulting in many cases in economic benefits to the state, nation and world. To learn more, visit http://vpr.tamu.edu.

About Fermilab: Fermilab, America’s premier national laboratory for particle physics research, is a Department of Energy national laboratory operated under contract by the Fermi Research Alliance, LLC. The DOE Office of Science is the single largest supporter of basic research in the physical sciences in United States.

News release courtesy of Fermilab. All information contained is distributed by Fermilab and the National Optical Astronomy Observatory (NOAO) on behalf of the Dark Energy Survey collaboration. NOAO’s facilities in the southern hemisphere are operated under the Cerro Tololo Inter-American Observatory, headquartered in La Serena, Chile. NOAO is operated by the Association of Universities for Research in Astronomy (AURA), Inc. under cooperative agreement with the National Science Foundation.

Additional information about the project can be found in this previous release, which features additional photographs and illustrations.

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Contact: Shana K. Hutchins, (979) 862-1237 or shutchins@science.tamu.edu or Dr. Darren DePoy, (979) 862-2082 or depoy@physics.tamu.edu