Electron Acceleration and Jet-Facilitated Escape in an M Class Solar Flare on 2002 August 19

TL;DR

This study combines multi-wavelength observations and modeling to analyze electron acceleration and escape mechanisms in a solar jet during an M-class flare, providing new constraints on electron distributions and acceleration timescales.

Contribution

It introduces a comprehensive multi-instrument approach and 3D modeling to better understand electron acceleration and escape in solar jets, which was less constrained in prior studies.

Findings

Detection of microwave gyrosynchrotron emission from an open magnetic field configuration.

Electron acceleration timescales on the order of 1 second or shorter.

Most stringent constraints to date on accelerated electrons in a solar jet.

Abstract

Sudden jets of collimated plasma arise from many locations on the Sun, including active regions. The magnetic field along which a jet emerges is often open to interplanetary space, offering a clear "escape route" for any flare-accelerated electrons and making jets lucrative targets for studying particle acceleration and the solar sources of transient heliospheric events. Bremsstrahlung hard X-rays (HXRs) could, in principle, trace the accelerated electrons that escape along the paths of the jets, but measurements of the escaping electron beams are customarily difficult due to the low densities of the corona. In this work, we augment HXR observations with gyrosynchrotron emission observed in microwaves, as well as extreme ultraviolet (EUV) emission and modeling to investigate flare-accelerated electrons in a coronal jet. HXR and microwave data from RHESSI and OVSA, respectively, give complementary insight into electron spectra and locations, including the presence of accelerated electrons in the jet itself. High-time-resolution HXR data from the Konus-Wind instrument suggest electron acceleration timescales on the order of 1 second or shorter. We model the energetic electron distributions in the GX Simulator framework using SoHO/MDI, RHESSI, TRACE, and OVSA data as constraints. The result is a modeled distribution, informed and constrained by measurements, of accelerated electrons as they escape the Sun. Combining the detection of microwave gyrosynchrotron emission from an open, rather than closed, magnetic configuration, with realistic 3D modeling constrained by magnetograms, EUV, and X-ray emission, we obtain the most stringent constraints to date on the accelerated electrons within a solar jet.