Spatial rays spread across the entire EM spectrum. Microwaves come from a variety of sources, including powerful masers and megamasers. The most intense are the active galactic nuclei, fed from the giant black holes in the centers.
The picture shows two galactic formations: MCG + 01-38-004 (top, reddish) and MCG + 01-38-005 (bottom, bluish). The second is considered a special type of megamazer class. Its core pumps out large-scale energy reserves, which stimulates the surrounding water clouds. Hydrogen and oxygen atoms can absorb some of the energy and emit it again in the microwave mode. Therefore, MCG + 01-38-005 is called the water megamizer!
These objects are important because they allow us to study the fundamental universal characteristics. The rays from MCG + 01-38-005 were used in the derivation of the Hubble constant.