The Optics of Refractive Substructure
Abstract
Newly recognized effects of refractive scattering in the ionized interstellar medium have broad implications for very long baseline interferometry (VLBI) at extreme angular resolutions. Building upon work by Blandford & Narayan (1985), we present a simplified, geometrical optics framework, which enables rapid, semi-analytic estimates of refractive scattering effects. We show that these estimates exactly reproduce previous results based on a more rigorous statistical formulation. We then derive new expressions for the scattering-induced fluctuations of VLBI observables such as closure phase, and we demonstrate how to calculate the fluctuations for arbitrary quantities of interest using a Monte Carlo technique.
Cite
@article{arxiv.1606.06315,
title = {The Optics of Refractive Substructure},
author = {Michael D. Johnson and Ramesh Narayan},
journal= {arXiv preprint arXiv:1606.06315},
year = {2016}
}
Comments
11 Pages, 4 Figures, Accepted for publication in ApJ