The Millisecond Pulsar Unveiling

Millisecond pulsars are believed to be form in binary systems comprised of a low-mass star and a neutron star, an LMXB.   As matter flows from the low-mass star onto the neutron star through an accretion disk, angular momentum flows as well.   Millisecond radio pulsars are especially common in globular clusters where such LMXBs are also common and the number of LMXBs in such systems agreed well with the numbers of millisecond pulsars in globular clusters and elsewhere.  Finally, several accreting neutron stars have been discovered with millisecond spin periods.   A final piece in the puzzle was the discovery of radio pulsations from PSR J102347.67+003841.2 in 2007.   This object spends sometime as an accreting neutron star from observations as late as 2000 and 2001 (from x-ray and optical measurement), and by 2007 the accretion disk had all but disappeared.   The first paper outlines a mechanism where gamma-rays produced near the light cylinder of the millisecond pulsar are sufficient to ablate the accretion disk entirely within such a short time.  The second paper provides a recent observational update on this really cool pulsar.

http://arxiv.org/abs/1009.4781 On the Transition from Accretion Powered to Rotation Powered Millisecond Pulsars

http://arxiv.org/abs/1008.1068 X-ray Variability and Evidence for Pulsations from the Unique Radio Pulsar/X-ray Binary Transition Object FIRST J102347.6+003841