  Intracluster gas velocity gradients have been recently detected by the
authors in the Centaurus cluster (Abell 3526) using the Doppler shift of X-ray
spectral lines with ASCA Solid-state Imaging Spectrometers. The velocity
gradient was found to be maximum along a line roughly perpendicular to the
direction of the incoming subgroup Cen 45 and has a correspondent velocity
difference of ~ (3.4+-1.1) x 1000 km/s within a ~10'-diameter region centered
on the cD galaxy NGC 4696. Such bulk velocities should Comptonize the Cosmic
Microwave Background Radiation producing variations of intensity and
temperature that can be detectable in the near future with bolometers such as
BOLOCAM . In this paper we realistically estimate the expected CMBR
Comptonization for the central region of Abell 3526, using ASCA and ROSAT data
to constrain the S-Z parameter expectations.
