Speaker
Description
First Name: Barbara
Last Name: Palumbo
Affiliation: Università degli Studi di Genova
All Authors: B. Palumbo, P. Massa, M. Stiefel, D. Ryan, H. Collier, Y. Su, M. Piana, and Säm Krucker
Abstract: Since April 2023, Solar Orbiter/STIX (Spectrometer Telescope for Imaging X-rays) and ASO-S/HXI (Hard X-ray Imager) provide simultaneous hard X-ray observations of solar flares from different vantage points. The measurements acquired by STIX and HXI can be mathematically described as two-dimensional (2D) Fourier components of the three-dimensional (3D) X-ray emission integrated along each instrument’s line of sight. Therefore, by combining the Fourier components (or visibilities) provided by both spacecraft from complementary viewpoints, it is possible to reconstruct the 3D intensity distribution of the flaring X-ray emission. We provide an overview of the methodology we developed to obtain 3D reconstructions of the thermal X-ray emission in solar flares from a set of combined STIX and HXI visibilities. We present the first 3D reconstructions of the X9.1 GOES class flare occurred on 3 October 2024, which is an ideal event since STIX and HXI were separated by a relative angle of approximately 90° with respect to the flaring site. From the 3D reconstructions we retrieve the altitude of the thermal X-ray source above the solar surface and its radial velocity, and we investigate their evolution over time. Our results demonstrate potential of multi-spacecraft hard X-ray observations for the study of solar flares.