  We report here an investigation of the X-ray eclipse transitions of the high
mass X-ray binary pulsar Cen X-3 in different intensity states. Long term light
curve of Cen X-3 obtained with RXTE-ASM spanning for more than 5000 days shows
strong aperiodic flux variations with low and high states. We have investigated
the eclipse transitions of Cen X-3 in different intensity states with data
obtained from pointed observations with the more sensitive instruments on board
ASCA, BeppoSAX, XMM-Newton, Chandra and RXTE. We found a very clear trend of
sharp eclipse transitions in the high state and longer transitions in the low
state. This is a confirmation of this feature first observed with the RXTE-ASM
but now with much better clarity. From the light curves obtained from several
missions, it is seen that the eclipse egress in the low state starts earlier by
an orbital phase of 0.02 indicating that the observed X-rays originate from a
much larger region. We have also performed spectral analysis of the
post-eclipse part of each observations. From BeppoSAX observations, the
out-of-eclipse X-ray fluxes is found to differ by a factor of ~ 26 during the
high and low intensity states while the eclipse count rates differ by a factor
of only ~ 4.7. This indicates that in the low state, there is an additional
scattering medium which scatters some of the source photons towards the
observer even when the neutron star is completely eclipsed. We could also
resolve the three iron line components using XMM-Newton observation in the low
state. By comparing the iron line equivalent width during the high and low
states, it is seen that the width of iron line is relatively large during the
low state which supports the fact that significant reprocessing and scattering
of X-rays takes place in the low state.
