# Why do some neutron stars become pulsars? [duplicate]

I suspect this may be an open problem in astronomy, but I have to ask anyway.

There doesn't seem to be any large-scale difference in the formation of pulsars from the formation of "normal" neutron stars. Yet pulsars end up emitting electromagnetic radiation, while others - "radio quiet" neutron stars - do not.

Why do are some neutron stars formed as pulsars, while others are not?

This is partly based on What causes a star to become a pulsar?, but the answer does not cover this part.

The pulsar phenomenon is also transient. Once the rotational kinetic energy of the pulsar has been extracted and it spins down beyond the "pulsar death line", or if magnetic field decay occurs rapidly, then the pulsar should switch off. Most of the billion (or so) neutron stars in our Galaxy are no longer pulsars. The slope of the death line is such (e.g. see Arons 1999) that even if the pulsar is born with a relatively weak field ($10^{6}$ T !) it should still be born with a rotation period short enough ($<1$ s) to produce the pulsar phenomenon initially.