Discovery points to origin of mysterious ultraviolet radiation

Lyman-alpha blobs (LABs) are gigantic clouds of hydrogen gas that produce ultraviolet light known as Lyman-alpha emissions. A study of Lyman-alpha blob 6 (LAB-6) is the first LAB with infalling gas feature. The findings suggest that star-forming galaxies are likely the primary energy source of Lyman-alpha radiation emitted from LAB-6.