Is the 1.5-ms pulsar a young neutron star

The 1.5-ms pulsar PSR1937+214 is an unusual object; its extremely short period and slow spin-down rate imply a magnetic field of 4 x 108 G, much lower than that of a canonical pulsar. The authors propose that PSR1937+214 is a young neutron star spun up by accretion from a high-mass companion in a close binary system. The super-critical mass transfer rates expected in such a binary system should allow the neutron star to be spun up in the comparatively short time of approx. 104 yr. The accretion process will also power thermomagnetic effects that could remove the strong magnetic field of a young pulsar from the crust of the star in a similarly short timescale. Such a high-mass binary system is expected to disrupt when the companion explodes in a supernova. Thus a spin-up model in a high-mass system can explain the lack of a companion, low magnetic field, and high spin rate of PSR1937+214. (author)