Possible Origin of RHIC R_{out}/R_{sid} HBT Results

The effects of opacity of the nuclei together with a blackbody type of emission along the system history are considered as a means to explain the ratio $R_{out}/R_{sid}$ observed by STAR and PHENIX collaborations at RHIC. Within our model, no flow is required to explain the data trend of this ratio for large surface emissivities.