Observations of magnetic reconnection and particle acceleration locations in solar coronal jets

TL;DR

This study analyzes solar coronal jets using multi-wavelength data, revealing multiple particle acceleration sites and detailed plasma temperature evolution, providing new insights into jet formation and energy distribution.

Contribution

It introduces the first DEM analysis combining AIA, XRT, and RHESSI data for coronal jets, identifying multiple electron acceleration sites and detailed plasma heating and cooling processes.

Findings

HXR emissions found at multiple locations, including the corona.

Non-thermal electrons contain significant energy and are accelerated near the jet top.

Jet velocities are consistent with previous measurements, with fast outflows of 400-700 km/s.

Abstract

We present a multi-wavelength analysis of two flare-related jets on November 13, 2014, using data from SDO/AIA, RHESSI, Hinode/XRT, and IRIS. Unlike most coronal jets where hard X-ray (HXR) emissions are usually observed near the jet base, in these events HXR emissions are found at several locations, including in the corona. We carry out the first differential emission measure (DEM) analysis that combines both AIA (and XRT when available) bandpass filter data and RHESSI HXR measurements for coronal jets, and obtain self-consistent results across a wide temperature range and into non-thermal energies. In both events, hot plasma first appeared at the jet base, but as the base plasma gradually cooled, hot plasma also appeared near the jet top. Moreover, non-thermal electrons, while only mildly energetic, are found in multiple HXR locations and contain a large amount of total energy. Particularly, the energetic electrons that produced the HXR sources at the jet top were accelerated near the top location, rather than traveling from a reconnection site at the jet base. This means that there was more than one particle acceleration site in each event. Jet velocities are consistent with previous studies, including upward and downward velocities around ~200 km/s and ~100 km/s respectively, and fast outflows of 400-700 km/s. We also examine the energy partition in the later event, and find that the non-thermal energy in accelerated electrons is most significant compared to other energy forms considered. We discuss the interpretations and provide constraints on mechanisms for coronal jet formation.