This is a pulsar. Well, an artists rendition of a pulsar. A pulsar is an extremely dense star (though, technically not fusing atoms any more) known as a neutron star that has a huge amount of mass in  a tiny (relative) small volume. It pulls interstellar debris towards its core, accelerating it at an enormous rate towards the poles. So fast that the material radiates energy away in the X-ray and higher energy rays area of the spectrum. Cool eh?