Axions Around Neutron Stars?

[PatrickPowers]

Axions are particles that look very good in theory but have never been detected. The latest idea is that young hot neutron stars would produce prodigious quantities of axions. Young neutron stars have a temperature of over half a billion degrees centigrade so they are too hot to be superfluid. Within such stars there is an astronomical number of very high speed collisions of nucleons, each producing an axion. The intense gravity of the star would capture a lot of them, making for a very dense cloud surrounding the star. The extreme magnetic field of the star would occasionally decompose some of the axions to "hard X rays." Such X rays have been detected from seven isolated young hot neutron stars. It is claimed that axions, or maybe axion-like particles, are the best explanation for this.