Prospects for detection of intracluster gas bulk velocities through the Sunyaev-Zeldovich effect

Intracluster gas velocity gradients have been recently detected by the authors in the Centaurus Cluster (A3526) 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 similar to(3.4 +/- 1.1) x 10(3) km s(-1) within a similar to10' diameter region centered on the cD galaxy NGC 4696. Such bulk velocities should Comptonize the cosmic microwave background radiation (CMBR) 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 A3526, using ASCA and ROSAT data to constrain the Sunyaev-Zeldovich parameter expectations.