A rigorous treatment of the refractive scintillations of extragalactic radio sources caused by a two-component interstellar medium is discussed. The structure functions D(τ) of flux variations caused by refractive scintillations are calculated. It is shown that the power-law index p(D(τ)∝τp) of the structure function depends on the relative scattering strength of the thin screen and the continuous medium. The proposed model can be applied to interpret the different types of structure functions observed in extragalactic radio sources and in pulsars, especially in the case of p ≅ 1.5.
Acta Astronomica Sinica
- Pub Date:
- December 1996
- Interstellar Matter: Scintillations;
- Radio Sources: Scintillations;
- Pulsars: Scintillations