  We present the results obtained from broadband spectroscopy of the high mass
X-ray binary 4U 1700-37 using data from a Suzaku observation in 2006 September
13-14 covering 0.29-0.72 orbital phase range. The light curves showed
significant and rapid variation in source flux during entire observation. We
did not find any signature of pulsations in the light curves. However, a
quasi-periodic oscillation at ~20 mHz was detected in the power density
spectrum of the source. The 1-70 keV spectrum was fitted with various continuum
models. However, we found that the partially absorbed high energy cutoff
power-law and Negative and Positive power-law with Exponential cutoff (NPEX)
models described the source spectrum well. Iron emission lines at 6.4 keV and
7.1 keV were detected in the source spectrum. An absorption like feature at ~39
keV was detected in the residuals while fitting the data with NPEX model.
Considering the feature as cyclotron absorption line, the surface magnetic
field of the neutron star was estimated to be ~3.4 times 10^12 Gauss. To
understand the cause of rapid variation in the source flux, time-resolved
spectroscopy was carried out by dividing the observation into 20 narrow
segments. The results obtained from the time-resolved spectroscopy are
interpreted as the accretion of inhomogeneously distributed matter in the
stellar wind of the supergiant companion star as the cause of observed flux
variation in 4U 1700-37. A sharp increase in column density after ~0.63 orbital
phase indicates the presence of an accretion wake that blocks the continuum and
produces the eclipse like low-flux segment.
