Why do some supernova remnants contain pulsars?
This nebula is the product of a supernova explosion; in this section, the blast wave has encountered an area of dense interstellar gas, creating turbulence in the wave and causing it to glow. The picture is a composite of three images taken by the Hubble Space Telescope.
Some supernova remnants contain pulsars because these objects are the dense, rapidly rotating neutron star cores left behind after a massive star undergoes a supernova explosion.12
When the core of a dying star collapses, it can form a neutron starāan extremely dense object typically about 20 km in diameter. If this neutron star possesses a powerful magnetic field and rotates, it can accelerate charged particles to near-light speeds, producing intense beams of electromagnetic radiation that sweep through space like a lighthouse beam.314
While many supernova remnants are associated with these remnants, only about 50 are known to contain detectable pulsars. Several factors explain why others may not appear to contain one:2
* The pulsar may have been ejected from the remnant due to recoil from an asymmetrical explosion.2
* The supernova may have formed a black hole instead of a neutron star.2
* The pulsar's radiation beam may simply not sweep across the solar system, making it undetectable from Earth.2