Torque-luminosity correlation and possible evidence for core-crust relaxation in the X-ray pulsar GX 1+4

B. Paul, A. R. Rao, K. P. Singh

We present the detection of a positive correlation between spin-down rate $\dot{P}$ and pulsed X-ray luminosity in the BATSE archival data of the bright hard X-ray pulsar GX 1+4. W…