X-rays From Other Galaxies Could Emanate From Particles of Dark Matter

sciencehabit writes "X-rays of a specific wavelength emanating from the hearts of nearby galaxies and galaxy clusters could be signs of particles of dark matter decaying in space, two independent teams of astronomers report (first study, second study). If that interpretation is correct, then dark matter could consist of strange particles called sterile neutrinos that weigh about 1/100 as much as an electron."

Comments

Re:That's "strange weird" not "strange flavor"

[Anonymous Coward]

I don't understand how something with only 7kEv * c^2 of mass won't be seen already. Even if it shares no property with normal matter, I'd expect it to appear from bare energy + momentum available at accelerators*... Or are people just classifying them as normal neutrinos?

Sterile neutrinos lack the weak interaction of normal neutrinos. The process that allows accelerators and nuclear processes to produce normal neutrinos is through the weak force. In the same way you can't take a photon and turn it directly into a neutrino + anti-neutrino because they don't interact with electromagnetism, you can't take "bare energy and momentum" to produce sterile neutrinos easily in accelerators. More subtle approaches look for them in accelerators, but having a light mass means you need quite a bit of precision to account for missing energy, and a situation distinguishable from say a normal neutrino. Search attempts also involve looking at neutrino oscillations closely, because of various models allowing mixing between normal and sterile neutrinos that could cause them to come up or affect neutrinos emitted from processes that can't emit a sterile neutrino directly.