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PERIMETER INSTITUTE RECORDED SEMINAR ARCHIVE

PIRSA:14110105  ( MP4 Medium Res , MP3 , PDF ) Which Format?
Deblurring Sgr A* Images
Speaker(s): Michael Johnson
Abstract: Scattering in the tenuous interstellar plasma blurs the image of Sgr A*. This effect decreases steeply with increasing frequency and becomes subdominant to the intrinsic emission structure at wavelengths close to a millimeter. I will discuss recent work that demonstrates how we can invert the blurring when properties of the scattering are known. With this technique, we can reconstruct the unscattered image of Sgr A* using EHT data. I will also show why some EHT observables -- such as closure phase and fractional polarization -- are largely immune to scattering. Finally, despite decades of study, there has been a recent flurry of progress in understanding the scattering properties, including studies of the Galactic Center magnetar and the discovery of refractive substructure in the scattering disk of Sgr A* at 1.3-cm wavelength. I will discuss these recent findings and their implications for imaging Sgr A* with the EHT
Date: 14/11/2014 - 10:45 am
Collection: EHT 2014
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