The microarcsecond sky and cosmic turbulence

摘要: Radio waves are imprinted with propagation effects from ionized media through which they pass. Owing to electron density fluctuations, compact sources (pulsars, masers, and extragalactic sources) can display a wide variety of scattering effects. These effects, particularly interstellar scintillation, be exploited provide superresolution, achievable angular resolutions ( I pas) far in excess what obtained by very long baseline interferometry on terrestrial baselines. Scattering also powerful sub-A U probe the microphysics medium, potentially spatial scales smaller than 100 km, as well tracer Galactic distribution energy input into medium integrated measures. Coupled future gamma-ray observations, SKA observations may means detecting fainter sources. Though it is not yet clear that due intergalactic significant, will either detect or place stringent constraints scattering. (C) 2004 Published Elsevier B.V.