The 570-Megapixel Dark Energy Camera’s Dazzling View of 230 Sparkling Galaxies

‘The Antlia Cluster (Abell S636) is a group of at least 230 galaxies located about 130 million light-years away in the direction of the constellation Antlia (the Air Pump).’ | Credit: Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA, Image processing: R. Colombari & M. Zamani (NSF NOIRLab)

The groundbreaking Dark Energy Camera (DECam) entered service in 2012 and served as the primary camera used for the Dark Energy Survey. The 570-megapixel camera, which features 74 total CCD image sensors, recently captured a dazzling photo of the Antlia Cluster (Abell S636), a group of at least 230 galaxies located about 130 million light-years from Earth.

Located inside the Victor M. Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory in Chile, the Dark Energy Camera is a wide-field CCD imager with 62 science CCDs and a dozen CCDs that control guidance and focus. The 62 science CCDs deliver 520 total megapixels of resolution, while the additional sensors are 50 megapixels. Including the sensors, lenses, and filter array, the entire DECam apparatus weighs about four tons, or to borrow from Chris Niccolls, about 1,814 Nocts.

‘The DECam focal plane consists of a science array of 62 2,048 x 4,096 CCDs. Additionally there are four 2,048 x 2,048 guider CCDs and eight 2,048 x 2,048 focus and alignment CCDs. The quantum efficiency of these LBNL-designed CCDs with their anti-reflective coating is red optimized to be greater than 90% at 900 nm and over 60% over the range of 400-1000 nm. The DES CCDs were fabricated by Dalsa with further processing done by LBNL. They were then packaged and tested by Fermilab.’ | Credit: DOE/FNAL/DECam/R. Hahn/CTIO/NOIRLab/NSF/AURA

After a lengthy calibration period, the Dark Energy Survey’s observation period lasted from August 2013 until January 9, 2019. Since then, scientists have continued working through all the data the Dark Energy Camera captured. The DECam has also been used for other surveys, including the Dark Energy Camera Legacy Survey, the DESI Legacy Imaging Surveys, and the Dark Energy Camera Plane Survey.

The new image of the Antlia Cluster shows a diverse group of galaxy types, including lenticular galaxies, irregular galaxies, and even ultra-compact dwarf galaxies, per NOIRLab. The full-resolution version is available to download from NOIRLab.

This is the Dark Energy Camera’s one-millionth exposure combined with 127 other earlier exposures to create a wide field frame. The largest visible galaxy here is the spiral galaxy ESO 440-11, flanked by several large galaxy clusters and thousands of other galaxies. Some of the Milky Way’s stars are also featured in the photo. | Credit: Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA; Acknowledgments: T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), M. Zamani (NSF’s NOIRLab) & D. de Martin (NSF’s NOIRLab)

Given that the Dark Energy Survey observation period covered 5,000 square degrees of the southern night sky, it is no surprise that scientists are still working through the data and learning new things about the cosmos. The Dark Energy Camera captured over one million exposures, and a single image covers an area of the sky that is about 20 times the average visible size of the Moon as seen from Earth. That’s a lot of data.

Image credits: Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA