2,3,- 1Department of Mathematics, Università degli Studi di Genova, Genova, Italy (barbara.palumbo@edu.unige.it, michele.piana@unige.it)
- 2Institute of Data Science, University of Applied Sciences and Arts Northwest Switzerland (FHNW), Windisch, Switzerland (paolo.massa@fhnw.ch, muriel.stiefel@fhnw.ch, hannah.collier@fhnw.ch, samuel.krucker@fhnw.ch)
- 3Swiss Federal Institute of Technology in Zurich (ETHZ), Zürich, Switzerland
- 4Mullard Space Science Laboratory, University College London, Holmbury St Mary, United Kingdom (daniel.ryan@ucl.ac.uk)
- 5Division of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences (CAS), Nanjing, China (yang.su@pmo.ac.cn)
- 6School of Astronomy and Space Science, University of Science and Technology of China, Hefei China
- 7Istituto Nazionale di Astrofisica, Osservatorio Astrofisico di Torino, Pino Torinese, Italy
- 8Space Sciences Laboratory, University of California, Berkeley, USA
Since April 2023, solar flares have been simultaneously observed by the Spectrometer/Telescope for Imaging X-ray (STIX) onboard ESA’s Solar Orbiter and by the Hard X-ray Imager (HXI) onboard the Chinese ASO-S mission. The two telescopes independently measure 2D Fourier components (visibilities) of the flaring X-ray radiation from different vantage points. However, by combining their datasets, it is possible to obtain a sampling of the 3D Fourier transform of thermal hard X-ray sources in solar flares. This combined dataset allows reconstructing the 3D morphology of the flaring sources by solving an inverse imaging problem.
In this presentation, we describe the methodology we developed for 3D reconstruction of thermal hard X-ray sources in solar flares from combined STIX/HXI data. We present the results obtained in the case of the X9.1 GOES class event which occurred on October 3, 2024. During this event, the two instruments were in an ideal configuration, where the separation angle between them and the flaring site was approximately 90 degrees. We validate the 3D reconstruction by comparing them with the 2D images independently reconstructed from STIX and HXI data. Finally, we determine the altitude of the reconstructed X-ray source above the solar surface as a function of time, and we derive estimates of its radial velocity.
How to cite: Palumbo, B., Massa, P., Stiefel, M., Ryan, D., Collier, H., Su, Y., Piana, M., and Krucker, S.: 3D reconstruction of thermal hard X-ray sources in solar flares from combined STIX and HXI visibilities, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12658, https://doi.org/10.5194/egusphere-egu26-12658, 2026.
