by Simon Johnston (CASS)

As part of the ATESE project, Tuntsov et al. took data with the Compact Array on the quasar PMN J1106-3607. Large variations in the flux density and the spectrum were seen as shown in the Figure which shows (top) the entire 1000 day monitoring period and (bottom) a zoom-in of 100 days worth. Tuntsov et al. interpret the variations as interstellar scintillation, both diffractive and refractive, of a source that is compact but not point-like. The scattering material is only some 50 pc distant and has a sharp concave boundary.