Every night, on a mountain top high in the Chilean Andes, a new instrument images a portion of the southern sky collecting light emitted by distant galaxies billions of years ago. A team of physicists and astronomers from Ohio State University collaborated with more than a hundred scientists from three continents to build and operate DECam, the Dark Energy Camera. DECam is a large 570 Megapixel camera with 74 custom designed CCDs and a record setting field of view, covering in a single exposure an area of the sky 20 times the size of the full moon as seen from earth. The tools used by the observers to operate DECam, the data acquisition system and the software to monitor and record the status of the instrument were all created by the OSU team led by Prof. Klaus Honscheid. 

DECam is used by the Dark Energy Survey collaboration to probe the origin of the accelerating expansion of the universe. This five-year program is designed to uncover the nature of dark energy and to determine whether Einstein’s general relativity is valid on the largest scales. The exquisite image quality and operational efficiency required for these studies were demonstrated and optimized during a 10-month science verification period co-chaired by Prof. Honscheid. During this effort, DECam imaged more than 150 sq. degrees of the sky in five different filter bands. Led by CCAPP Fellows Melchior and Huff, the analysis of this data sample, the largest of this kind available to date, is ongoing and first results will soon be published.

More information about DECam and the Dark Energy Survey can be found at  www.darkenergysurvey.org

The full article is available at Physics Today Online.