Evolution of cross-correlation and time lag of Cyg X-2 along the branches

Y. J. Lei, J. L. Qu, L. M. Song +6

We report the detections of the anti-correlated soft and hard X-rays, and the time lags of $\sim$ hecto-second from the neutron star low-mass X-ray binary Cyg X-2, a well-known Z-t…