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Session 17 - The Galactic Interstellar Gas.
Display session, Monday, January 13
The apparent sizes of radio sources increase when they are observed through the solar wind due to turbulent fluctuations of electron density. The defining characteristics of this turbulence are the inner and outer scales, corresponding to the smallest and largest lengthscales on which the fluctuations occur; and a power spectral index, which relates the relative strength of large and small scale fluctuations. For the solar wind the turbulence is seen to extend from an inner scale of a few kilometers to an outer scale well beyond a few thousand kilometers, while the spectral index seems to change with spatial scale and orientation. The physics of turbulence in the solar wind is not well established theoretically due to the lack of uniform sets of observations of the solar wind under nearly identical conditions. We have carried out three epochs of multi-wavelength VLA and VLBA observations of the radio source 3C279 during the Sun's annual 'flyby'. We will report on measurements of the spectrum of the turbulence over more than three decades of spatial scales, at a variety of solar elongations, and at a wide range of wavelengths.
Program listing for Monday