Forward Modeling of Synthetic EUV/SXR Emission from Solar Coronal Active Regions: Case of AR 11117

TL;DR

This paper develops a detailed 1D hydrodynamic model to generate synthetic EUV/SXR emission images of solar active region AR 11117, comparing them with observations to understand coronal heating mechanisms.

Contribution

It introduces a method to construct realistic synthetic emission images of a specific active region using magnetic field data and impulsive heating models, advancing coronal heating studies.

Findings

Synthetic EM images closely match observed DEMs.

Impulsive heating models reproduce both EUV and SXR emissions.

Magnetic field scaling improves the accuracy of emission predictions.

Abstract

Recent progress in obtaining high spatial resolution images of the solar corona in the extreme-ultraviolet (EUV) with Hinode, TRACE, SDO and recent Hi-C missions and soft X-ray (SXR) bands opened a new avenue in understanding the solar coronal heating, the major goal of solar physics. The data from EUV/SXR missions suggest that solar corona is a non-uniform environment structured into active regions (AR) represented by bundles magnetic loops heated to temperatures exceeding 5 MK. Any viable coronal heating model should be capable of reproducing EUV and SXR emission from coronal active regions well as dynamic activity. Measurements of emission measures (EM) for ARs provide clues to time dependence of the heating mechanism: static versus impulsive. While static equilibrium coronal loop models are successful in reproducing SXR emission within an AR, they cannot adequately predict the bright EUV loops. Meantime, impulsive heating is capable in reproducing both EUV and SXR loop emission. The major goal of this paper is to construct realistic synthetic EM images of specific solar corona active region, AR 11117 by using our 1D fully non-linear time-dependent single-fluid hydrodynamic code. We first construct a magnetic skeleton for the entire active region using the HMI/SDO magnetogram for AR 11117 and populate magnetic field lines with plasma. We then parametrically specify impulsive heating of individual strands (flux tubes) comprising coronal loops. Next, we simulated the response of the entire active region (with LOS projection effects) to the heating function (volumetric heating rate) scaled with magnetic field and spatial scale parameters and find the best match between synthetic and actual (reconstructed) DEMs obtained by SDO.