Volume 656, December 2021
Solar Orbiter First Results (Cruise Phase)
|Number of page(s)||9|
|Published online||14 December 2021|
Cosmic-ray flux predictions and observations for and with Metis on board Solar Orbiter
DiSPeA, University of Urbino Carlo Bo, Urbino (PU), Italy
2 INFN, Florence, Italy
3 INAF – Astronomical Observatory of Capodimonte, Naples, Italy
4 CNR – IFN, Via Trasea 7, 35131 Padua, Italy
5 CISAS, Centro di Ateneo di Studi e Attività Spaziali “Giuseppe Colombo”, via Venezia 15, 35131 Padua, Italy
6 Solar-Terrestrial Centre of Excellence – SIDC, Royal Observatory of Belgium, Ringlaan -3- Av. Circulaire, 1180 Brussels, Belgium
7 Dip. di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via G. Marzolo, 8, 35131 Padua, Italy
8 ASI – Italian Space Agency, Via del Politecnico snc, 00133 Rome, Italy
9 University of Florence, Physics and Astronomy Department, Largo E. Fermi 2, 50125 Florence, Italy
10 INAF Associated Scientist, Florence, Italy
11 Alma Mater University, Bologna, Italy
12 INAF – Astrophysical Observatory of Catania, Catania, Italy
13 INAF – Astrophysical Observatory of Torino, Turin, Italy
14 INAF – Institute for Space Astrophysics and Cosmic Physics, Milan, Italy
15 University of Catania, Physics and Astronomy Department “Ettore Majorana”, via S. Sofia 78, 95123 Catania, Italy
16 Catholic University @ NASA – GSFC, Maryland, USA
17 MPS, Göttingen, Germany
18 Astronomical Institute of the Czech Academy of Sciences, Ondřejov, Czech Republic
19 INAF – Astrophysical Observatory of Trieste, Trieste, Italy
20 Politecnico di Torino, Turin, Italy
21 NASA HQ, Washington, DC, USA
22 National Research Council of Italy and Institute for Electronics, Information Engineering and Telecommunications, University of Padua, Department of Information Engineering via Gradenigo, 6B, 35131 Padua, Italy
23 Institute of Experimental and Applied Physics, Kiel University, 24118 Kiel, Germany
Accepted: 8 June 2021
Context. The Metis coronagraph is one of the remote sensing instruments hosted on board the ESA/NASA Solar Orbiter mission. Metis is devoted to carry out the first simultaneous imaging of the solar corona in both visible light (VL) and ultraviolet (UV). High-energy particles can penetrate spacecraft materials and may limit the performance of the on-board instruments. A study of the galactic cosmic-ray (GCR) tracks observed in the first VL images gathered by Metis during the commissioning phase is presented here. A similar analysis is planned for the UV channel.
Aims. We aim to formulate a prediction of the GCR flux up to hundreds of GeV for the first part of the Solar Orbiter mission to study the performance of the Metis coronagraph.
Methods. The GCR model predictions are compared to observations gathered on board Solar Orbiter by the High-Energy Telescope in the range between 10 MeV and 100 MeV in the summer of 2020 as well as with the previous measurements. Estimated cosmic-ray fluxes above 70 MeV n−1 have been also parameterized and used for Monte Carlo simulations aimed at reproducing the cosmic-ray track observations in the Metis coronagraph VL images. The same parameterizations can also be used to study the performance of other detectors.
Results. By comparing observations of cosmic-ray tracks in the Metis VL images with FLUKA Monte Carlo simulations of cosmic-ray interactions in the VL detector, we find that cosmic rays fire only a fraction, on the order of 10−4, of the whole image pixel sample. We also find that the overall efficiency for cosmic-ray identification in the Metis VL images is approximately equal to the contribution of Z ≥ 2 GCR particles. A similar study will be carried out during the whole of the Solar Orbiter’s mission duration for the purposes of instrument diagnostics and to verify whether the Metis data and Monte Carlo simulations would allow for a long-term monitoring of the GCR proton flux.
Key words: cosmic rays / solar-terrestrial relations / instrumentation: detectors
© ESO 2021
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.