On the tomographic reconstruction of the 3D electron density for the solar corona from STEREO COR1 data

Abstract

We present for the first time a three-dimensional reconstruction of the electron density in the corona at distances from 1.5R⊙ to 4R⊙ using COR1 STEREO observations. The reconstruction is performed using a regularized tomography inversion method for two biweekly periods corresponding to Carrington Rotations 2058 and 2066. Images from the two STEREO spacecraft are used to compare the reconstructed density structures with coronal features located by triangulation. We find that the location of a bright tip of a helmet streamer obtained from the tomographic reconstruction is in good agreement with the location obtained by triangulation. The reconstructed density structure of the equatorial streamer belt is largely consistent with the variation of the current sheet derived from a potential magnetic field extrapolation for most of the equatorial region and for an MHD model of the corona. A zero-value density region in the reconstruction is identified with a low-density region seen in an EUVI image below the reconstruction domain. © The Author(s) 2009.