Polarization of X-ray emission from the Sgr B2 cloud

The Sgr B2 giant molecular cloud is claimed to be an “X-ray reflection nebula” - the reprocessing site of a powerful flare of the Sgr A* source, occurred few hundred years ago. The shape of the X-ray spectrum and the strength of the iron fluorescent line support this hypothesis. We argue that the most clean test of the origin of X-rays from Sgr B2 would be a detection of polarized emission from this source.