Solar Burst Analysis with 3D Loop Models

TL;DR

This study employs 3D loop models to analyze solar flares, revealing that homogeneous source assumptions are inadequate and highlighting the importance of inhomogeneous modeling for accurate flare parameter estimation.

Contribution

Introduces a comprehensive 3D dipolar magnetic field model and a large database for microwave emission, improving flare analysis accuracy over traditional homogeneous models.

Findings

Homogeneous source models can misestimate electron density and magnetic fields.

Inhomogeneous models better match observed microwave spectra.

Center darkening is a geometric property of loop-like flare sources.

Abstract

A sample of Nobeyama flares was selected and analyzed using loop model for important flare parameters. The model for the flaring region consists of a three dimensional dipolar magnetic field, and spatial distributions of non-thermal electrons. We constructed a database by calculating the flare microwave emission for a wide range of these parameters. Out of this database with more than 5,000 cases we extracted general flare properties by comparing the observed and calculated microwave spectra. The analysis of NoRP data was mostly based in the center-to-limb variation of the flare properties with looptop and footpoint electron distributions and for NoRH maps on the resultant distribution of emission. One important aspect of this work is the comparison of the analysis of a flare using an inhomogeneous source model and a simplistic homogeneous source model. Our results show clearly that the homogeneous source hypothesis is not appropriate to describe the possible flare geometry and its use can easily produce misleading results in terms of non-thermal electron density and magnetic field strength. A center darkening of flares was also obtained as a geometrical property of the loop-like sources.