Count-based spectral component imaging (CCI) of solar flares in X-rays
Abstract
X-ray emission in solar flares is produced by both multi-thermal plasma and accelerated electrons. Classical imaging approaches reconstruct X-ray intensity maps which contain contributions from multiple spectral components (e.g., hot, superhot, and non-thermal), and do not allow retrieving the morphology of the different components separately. We introduce a novel imaging technique, called "Count-based spectral Component Imaging (CCI)", to jointly reconstruct spatially resolved emission measure maps of the thermal components, and the electron flux distribution of the non-thermal component from data provided by the Spectrometer/Telescope for Imaging X-rays (STIX) aboard Solar Orbiter. We formulate a linear model linking the Differential Emission Measure (DEM), approximated by two thermal components, and the non-thermal electron flux to the observed counts. The resulting inverse problem is solved with the Richardson-Lucy algorithm. We apply CCI to STIX observations of SOL2024-10-01T22 and compare it with the previously developed Spectral Component Imaging (SCI) method, as well as classical imaging approaches. The reconstructed thermal and non-thermal components show good agreement with those obtained using SCI. This proof-of-concept study shows that CCI obtains results consistent with SCI but with fewer inputs. In contrast with SCI, CCI can also be applied to hard X-ray focusing optics imaging.
Related
- Quasi-periodic pulsations in solar and stellar flares
- Type I Solar Radio Bursts Modulated by Solar Flares
- On the altitude profile of lower ionospheric D-region response time delay during solar flares
- Electron acceleration by turbulent reconnection in solar flares
- Electron Acceleration by Turbulent Reconnection in Solar Flares
BibTeX
@misc{guidetti2026countbased,
title = {{Count-based spectral component imaging (CCI) of solar flares in X-rays}},
author = {Alessia Guidetti and Muriel Zoë Stiefel and Paolo Massa and Anna Maria Massone and Michele Piana and Säm Krucker},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.17178},
eprint = {2609.17178},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.17178},
}
RIS
TY - UNPB
TI - Count-based spectral component imaging (CCI) of solar flares in X-rays
AU - Alessia Guidetti
AU - Muriel Zoë Stiefel
AU - Paolo Massa
AU - Anna Maria Massone
AU - Michele Piana
AU - Säm Krucker
PY - 2026
DA - 2026/09/15
PB - arXiv
DO - 10.48550/arxiv.2609.17178
UR - https://arxiv.org/abs/2609.17178
AB - X-ray emission in solar flares is produced by both multi-thermal plasma and accelerated electrons. Classical imaging approaches reconstruct X-ray intensity maps which contain contributions from multiple spectral components (e.g., hot, superhot, and non-thermal), and do not allow retrieving the morphology of the different components separately. We introduce a novel imaging technique, called "Count-based spectral Component Imaging (CCI)", to jointly reconstruct spatially resolved emission measure maps of the thermal components, and the electron flux distribution of the non-thermal component from data provided by the Spectrometer/Telescope for Imaging X-rays (STIX) aboard Solar Orbiter. We formulate a linear model linking the Differential Emission Measure (DEM), approximated by two thermal components, and the non-thermal electron flux to the observed counts. The resulting inverse problem is solved with the Richardson-Lucy algorithm. We apply CCI to STIX observations of SOL2024-10-01T22 and compare it with the previously developed Spectral Component Imaging (SCI) method, as well as classical imaging approaches. The reconstructed thermal and non-thermal components show good agreement with those obtained using SCI. This proof-of-concept study shows that CCI obtains results consistent with SCI but with fewer inputs. In contrast with SCI, CCI can also be applied to hard X-ray focusing optics imaging.
ER -