Boston University investigates distribution of light in galaxies

Astronomers have started to look towards light from other galaxies, believing that the light quality being emitted may hold answers about the galaxies themselves. 

“If all host galaxies live at the center of elliptical dark matter, you would expect satellite galaxies to be symmetrically distributed, with roughly as many satellites on each side of the host galaxy,” Tereasa Brainerd, an astronomer, told Boston University.

The findings of Brainerd and Adam Samuels, a BU astronomy grad researcher, showed that blue host galaxies possessed 50% more satellite galaxies on one side than the other. Blue galaxies are in the active process of making stars and are recognizable due to their spiral appearance, similar to the Milky Way. 

The team found that galaxies that emit a red light are dead, which means they are no longer making new stars. 

Uneven distribution of light by galaxies around hosts may be due to younger galaxies, but there is still a great deal of uncertainty about what the distribution of light means, according to Boston University.

The team will be using a simulation of galaxy structures, the IllustrisTNG, to look for answers about dark matter and satellite galaxies.