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Paper: VLBA Imaging at 7 MM and Linear Polarimetric Observations at 6 CM and 3 MM of SGR A*
Volume: 186, The Central Parsecs of the Galaxy
Page: 80
Authors: Bower, G. C.; Falcke, H.; Backer, D. C.; Wright, M.
Abstract: We summarize the results of 7 mm VLBA imaging of Sgr A* and discuss some of the difficulties of accurately constraining the size of Sgr A* with VLBI observations. Our imaging results are fully consistent with the hypothesis that the VLBA image of Sgr A* is a resolved elliptical Gaussian caused by the scattering of an intervening thermal plasma. We show that determination of the minor axis size at 7 mm with the VLBA is very unreliable. We also present new polarimetric observations from the VLA and from the BIMA array of Sgr A*. At 4.8 GHz, we find an upper limit to the polarization of 0.1%. At 86 GHz, we report a marginal detection of 1 +/- 1% linear polarization. We discuss the effects of interstellar propagation on the linear polarization and consider the significance of very low intrinsic linear polarization in Sgr A*.
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