The astrophysics community has been abuzz this week with news of mysterious X-rays coming from the center of the Perseus Cluster.
This is interesting, mainly because:
- We thought there was dark matter at the center of the Perseus Cluster.
- There’s a strong working theory that dark matter is made up of undiscovered particles called sterile neutrinos.
- Sterile neutrinos, if they exist, give off X-rays when they decay.
This could be huge, because despite the fact that most of the universe is made up of dark matter we don’t actually know what it is. “Most of the universe is made up of sterile neutrinos” sounds only slightly better than “most of the universe is made up of dark matter,” but it at least gives astrophysicists something to go on. Right now they quite literally have nothing—dark matter doesn’t give off or reflect light, so there’s no way to see it (hence the name). And that’s exactly the way we would expect sterile neutrinos to behave.
Of course, it’s entirely possible that some dark matter is made up of sterile neutrinos while the majority is made up of other undiscovered particles that also don’t give off or reflect light, and we refer to this entire category of undiscovered particles as “dark matter.” But that’s unnecessarily complicated, and I really feel kind of guilty for bringing it up now. Let’s go with sterile neutrinos.