Overview

• Astronomers combined 28 hours of Dark Energy Camera data on the NSF Blanco 4-meter telescope to assemble the deepest optical image of Abell 3667 to date.
• The image exposes diffuse intracluster light forming a glowing bridge between the cluster’s two brightest galaxies, marking the first direct optical confirmation of their rapid subcluster merger.
• Long-exposure stacking also captured faint Milky Way cirrus strands in the foreground and millions of distant background galaxies.
• Anthony Englert et al. posted the findings as an arXiv preprint, providing rapid community access prior to journal publication.
• The forthcoming Vera C. Rubin Observatory LSST will extend these deep-imaging techniques across the entire southern sky during its ten-year survey.