Jun 04 2020
Fermi Bubbles
This June 2020 article on the Fermi Bubbles of the Milky Way Galaxy concerns mapping the bubbles in the visible light spectrum: https://phys.org/news/2020-06-optical-milky-fermi-probe.html
The bubbles were originally found in the gamma ray spectrum. Previous entries are here: https://www.fruechtetheory.com/blog/2010/11/25/light-lensing-and-the-gamma-ray-bubbles/, and here: https://www.fruechtetheory.com/blog/2010/11/29/lensing-answer/
As far as their purpose, they may help stabilize the plane of the Milky Way by emitting gamma rays in a narrow Gaussian centered on 7.562 x 10^22 Hz. I have read that researchers have found that the same type of bubbles exist at other galaxies as well.