An artist’s concept showing the gaseous halo surrounding a galaxy, illuminated by Lyman alpha emission. BX418’s gas halo is about ten times the size of the galaxy itself. Image credit: T. Klein/UWM
In a study recently published in The Astrophysical Journal Letters, lead author Dawn Erb of the University of Wisconsin-Milwaukee and her team – for the very first time – used new capabilities at W. M. Keck Observatory on Maunakea, Hawaii to examine Q2343-BX418, a small, young galaxy located about 10 billion light years away from Earth.
This distant galaxy is an analogue for younger galaxies that are too faint to study in detail, making it an ideal candidate for learning more about what galaxies looked like shortly after the birth of the universe.
BX418 is also attracting astronomers’ attention because its gas halo is giving off a special type of light. “In the last several years, we’ve learned that the gaseous halos surrounding galaxies glow with a particular ultraviolet wavelength called Lyman alpha emission. There are a lot of different theories about what produces this Lyman alpha emission in the halos of galaxies, but at least some of it is probably due to light that is originally produced ...