Microwave and Hard X-Ray Observations of the 2017 September 10 Solar Limb Flare

TL;DR

This study presents microwave and hard X-ray observations of a 2017 solar limb flare, revealing the spatial and energy distribution of high-energy electrons and their common origin in the flare region.

Contribution

First combined microwave imaging spectroscopy and hard X-ray analysis of a limb flare, providing new insights into electron populations and flare geometry.

Findings

Microwave and HXR sources originate from a common nonthermal electron population.

Microwave imaging provides broader volume coverage than HXR data.

EUV observations complement microwave and HXR data to reveal flare evolution.

Abstract

We report the first science results from the newly completed Expanded Owens Valley Solar Array (EOVSA), which obtained excellent microwave imaging spectroscopy observations of SOL2017-09-10, a classic partially-occulted solar limb flare associated with an erupting flux rope. This event is also well-covered by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) in hard X-rays (HXRs). We present an overview of this event focusing on microwave and HXR data, both associated with high-energy nonthermal electrons, and discuss them within the context of the flare geometry and evolution revealed by extreme ultraviolet (EUV) observations from the Atmospheric Imaging Assembly aboard the Solar Dynamics Observatory (SDO/AIA). The EOVSA and RHESSI data reveal the evolving spatial and energy distribution of high-energy electrons throughout the entire flaring region. The results suggest that the microwave and HXR sources largely arise from a common nonthermal electron population, although the microwave imaging spectroscopy provides information over a much larger volume of the corona.