Originally posted on 7/24/18 by the W. M. Keck Observatory
A team of astronomers has discovered a new way to unlock the mysteries of how the first galaxies formed and evolved.
In a study published [on July 24th, 2018] 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 analog 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 by star formation in the galaxy being absorbed and re-emitted by gas in the halo,” said Erb.
Erb’s team, which includes Charles Steidel and Yuguang Chen of Caltech, used one of the observatory’s newest instruments, the Keck Cosmic Web Imager (KCWI), to perform a detailed spectral analysis of BX418’s gas halo; its properties could offer clues about the stars forming within the galaxy.
For the rest of the story, please visit the W. M. Keck Observatory’s website.