The fastest moving pulsars are theoretically spinning neutron stars. They probably got their velocity from a kick from a supernova like Project Orion. http://chandra.harvard.edu/photo/2012/igrj11014/ http://chandra.harvard.edu/photo/2003/b1957/closer_look.html As I understand it, neutron stars have collapsed down to just the elementary particles of atoms. The question is, would such a star act like a particle and interact with photons like electrons and other free particles? I am intrigued with the fact that photons when hit by free particles convert to electrons and positrons. When an electron was simultaneously hit by 4 photons whose energy added up to the E=mC^2 energy of two electron masses they created an electron positron pair. http://www.hep.princeton.edu/~mcdonald/e144/science1202.html If the neutron star acts like a big particle it should have a huge cross-section many orders of magnitude larger than an electron and then could simultaneously interact with many orders of magnitude more less energetic photons to create electrons and positrons?