Tomographic Reconstruction of the Coronal Electron Density with SolO/Metis and Comparison with SoHO/LASCO-C2

ALBERTO M. VASQUEZ; FEDERICO A. NUEVO; ALEKSANDR BURTOVOI; HUGO GILARDY; PHILIPPE LAMY; MARCO ROMOLI; FEDERICA FRASSATI; ALESSANDRO BEMPORAD; RICHARD A. FRAZIN; ROBERTO SUSINO; NISHTHA SACHDEVA; WARD B. MANCHESTER IV

Monterrey

Conferencia; XIV COLAGE; 2024

ALAGE

We carried out three-dimensional (3D) reconstructions of the electron density of the solar corona based on visible light polarized brightness (pB) images taken by the {Metis coronagraph on board the Solar Orbiter mission. Due to its highly eccentric orbit, the {Metis field of view (FoV) varies from ~ 5.8-10.2 Rsun at its maximum aphelion of ~ 1 au, down to ~ 1.7-3.0 Rsun at its minimum perihelion of ~ 0.28 au. We selected for analysis three different periods during 2022 to exemplify the suitability of the synoptic images of the instrument to be used for tomographic reconstruction of different ranges of coronal heights at different times. For each period, we also implemented independent synchronous reconstructions based on LASCO-C2 pB images, which have a roughly constant FoV of ~ 2.3-6.1 Rsun. Within the overlapping FoV of the two instruments we compare the pB of their respective images, a task that is complicated by the fact that they have different points of view, as well as the reconstructed 3D electron density based on each data set. For the analized periods we find Median(pB_Metis/pB_C2) ~ 1.7 and Median(Ne_Metis/Ne_ C2) ~ 1.7. Our analysis then shows that tomographic reconstruction may have utility for instrument intercalibration as while the images obtained by an instrument greatly depend on its location, the reconstructed coronal does not depend on one’s viewpoint.