Scientists have just discovered that the beautifully vivid microwave glow known as anomalous microwave emission (AME) that can be seen scattered throughout different regions of the Milky Way is actually caused by diamond dust or, more technically, crystalline carbon.
Researchers have been aware for quite some time that this mysterious glow was caused by some type of tiny nanoparticle, but that particle has eluded scientists up until now, as ScienceAlert report.
To determine what could be causing the AME that they were seeing, scientists took some time to research protoplanetary discs created out of gas and dust that could be observed hovering around newly-formed stars. Out of 14 of these discs, AME could be spotted in three.
It was after careful observation of anomalous microwave emission around these protoplanetary discs that scientists became convinced that the deep glow they were witnessing was being caused by diamonds that were so small in size that even the tiniest grain of sand would be much larger by comparison.
At one point in time, scientists believed that polycyclic aromatic hydrocarbons (PAH), which are carbon-based, might be the cause of the microwave glow throughout the Milky Way. This is because these particular hydrocarbons are known to populate large areas of interstellar space and produce light.
Fortunately for scientists, nanodiamond dust also produces its own infrared light, and as it does this on a different wavelength, researchers were able to easily distinguish crystalline carbon from polycyclic aromatic hydrocarbons.
Out of the three instances where AME was spotted around protoplanetary discs, scientists were able to observe from the infrared light that the glow was being caused by tiny nanodiamonds.
As Jane Greaves of Cardiff University explained, it now appears that the most logical and likely explanation behind the microwave glow we see in the Milky Way is diamond dust.
“In a Sherlock Holmes-like method of eliminating all other causes, we can confidently say the best candidate capable of producing this microwave glow is the presence of nanodiamonds around these newly formed stars.”
It should be noted that nanodiamonds aren’t really a rarity when it comes to space and are quite often discovered hidden inside meterorites. When it comes to elements in our galaxy, carbon is also in the top five of the most prominent elements.
The new study on nanodiamonds as the cause of the glow of the anomalous microwave emission (AME) in the Milky Way can be read in Nature Astronomy.