Qiong Li and Zheng Cai

A Lyman-Alpha nebula is a concentration of hydrogen gas that glows from the heat generated by radiation outflows from a nearby galactic supermassive black hole. These are some of the largest objects in the universe and investigators suspect that they hold valuable clues to the process of galaxy formation in the early universe.

On this evening, Li and Cai will use the Cosmic Web Imager to increase the number of known giant Lyman-Alpha nebulae. They are particularly concerned with extended hydrogen nebulae that are associated with strongly clustered groups of Quasi-Stellar Objects.

In this composite of images taken at several wavelengths, a glowing hydrogen nebula, shown in yellow, extends for millions of light-years around a distant galaxy shown in white and red. The blue fringe around the galaxy is the result of X-ray emissions, evidence that a supermassive black hole lies its the center. (D. Alexander, S. Chapman, et. al.)