Detection of polarized millimeter and submillimeter emission from Sagittarius A

We report the detection of linear polarization from Sgr A* at 750, 850, 1350, and 2000 mu m which confirms the contribution elf synchrotron radiation. From the lack of polarization at longer wavelengths, it appears to arise in the millimeter/submillimeter excess. There are large position angle changes between the millimeter and submillimeter results, and these are discussed in terms of a polarized dust contribution in the submillimeter and various synchrotron models. In the model that best explains the data, the synchrotron radiation from the excess is self-absorbed in the millimeter region and becomes optically thin in the submillimeter. This implies that the excess arises in an extremely compact source of similar to 2 Schwarzschild radii.