A state change in the missing link binary pulsar system PSR J1023+0038

Understand

We present radio, X-ray, and gamma-ray observations which reveal that the binary millisecond pulsar / low-mass X-ray binary transition system PSR J1023+0038 has undergone a transformation in state.

• Whereas until recently the system harbored a bright millisecond radio pulsar, the radio pulsations at frequencies between 300 to 5000 MHz have now become undetectable.
• Concurrent with this radio disappearance, the gamma-ray flux of the system has quintupled.
• We conclude that, though the radio pulsar is currently not detectable, the pulsar mechanism is still active and the pulsar wind, as well as a newly formed accretion disk, are together providing the necessary conditions to create the gamma-ray increase.