Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-01-22
Astronomy and Astrophysics
Astrophysics
23 pages 106 figures accepted for publication in ApJ
Scientific paper
10.1086/533423
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-type luminous source. Both the anti-correlation and the positive correlation were detected during the low-intensity states, while only the latter showed up during high-intensity states. Comparing with the lower part of normal branch and flaring branch, more observations located on the horizontal and the upper normal branches are accompanied with the anti-correlation, implying the occurrence of the anti-correlation under circumstance of a low mass accretion rate. So far the anti-correlated hard lag of thousand-second timescale are only reported from the Galactic black hole candidates in their hard states. Here we provide the first evidence that a similar feature can also establish in a neutron-star system like Cyg X-2. Finally, the possible origins of the observed time lags are discussed under the current LMXB models.
Lei Yeong-Jyi
Li Zhi-Bing
Qu Jin Lu
Song Li Ming
Wang Janet M.
No associations
LandOfFree
Evolution of cross-correlation and time lag of Cyg X-2 along the branches does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Evolution of cross-correlation and time lag of Cyg X-2 along the branches, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolution of cross-correlation and time lag of Cyg X-2 along the branches will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-95180