This Is Where Space Blobs Come From

A computer simulation of a Lyman-alpha blob similar to LAB-1. (Credit: J.Geach/ D.Narayanan/ R.Crain) A combination of observation and modelling sheds new light on how Lyman-Alpha blobs form and why they shine so brightly. Lyman-Alpha blobs are among the rarest denizens of the distant universe. They’re giant clouds of hydrogen gas spanning hundreds of thousands of light years, named for the trademark radiation they emit. Now combined observations from several telescopes have given astrophysicists a look at what’s going on inside and what produces the characteristic radiation. For 15 years, physicists have speculated and debated about how these luminous cosmic blobs form and what’s going on inside them. This is an important question because Lyman-Alpha blobs appear to be the cosmic nurseries where the largest galaxies in the universe are born. Mapping out where Lyman-Alpha radiation comes from, and what it’s reflecting off of to form the glowing cloud we ...