If you thought studying dark matter was difficult, imagine how difficult it is to study dark energy. Dark energy is one of the universe’s most subtle phenomena. It drives cosmic evolution, but its effects are only visible on intergalactic scales. To study dark energy in depth, a large number of observations of large areas of the sky are required.
This is why the Department of Energy collaborated with astronomers to develop the Dark Energy Camera ten years ago (DECam). It has more than 60 imaging CCDs and captures images at 570 megapixels, making it the highest resolution astronomical camera ever built. It was installed at Chile’s Cerro Tololo Inter-American Observatory’s Victor M. Blanco 4-meter Telescope, where it has a field of view that is more than 2 degrees wide, or four times the apparent width of the Moon.
DECam took an average of 400-500 images per night between 2013 and 2019, looking at distant supernovae, measuring the scale at which galaxies cluster together, and studying the weak gravitational lensing of intergalactic dark matter. This data has helped astronomers constrain observations and better fit theoretical models to observations, giving us a better understanding of dark energy.
However, as DECam approached its tenth year of operation, the team decided to try something new. A high-resolution wide-field camera is excellent for capturing data, but it is also capable of producing some stunning images. As a result, the team pointed it at NGC 6357, also known as the Lobster Nebula. It is located approximately 8,000 light-years from Earth in the constellation Scorpius and is a hotspot for star formation. The results are shown in the image below, which is quite stunning.
The image spans approximately 400 light-years and depicts bright young stars among dense gas regions. The DECam team used narrow band filters to take images of specific colours within the nebula to capture the details of this image. The images were then combined and coloured to create the final image. It’s an incredible demonstration of what the DECam is capable of.
Of course, with a decade of experience under its belt, the DECam has no plans to slow down anytime soon. It recently captured its millionth image, and given enough time, it could capture a million more.