1
|
Massa P, Battaglia AF, Volpara A, Collier H, Hurford GJ, Kuhar M, Perracchione E, Garbarino S, Massone AM, Benvenuto F, Schuller F, Warmuth A, Dickson ECM, Xiao H, Maloney SA, Ryan DF, Piana M, Krucker S. First Hard X-Ray Imaging Results by Solar Orbiter STIX. Sol Phys 2022; 297:93. [PMID: 35891628 PMCID: PMC9307546 DOI: 10.1007/s11207-022-02029-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
The Spectrometer/Telescope for Imaging X-rays (STIX) is one of six remote sensing instruments on-board Solar Orbiter. The telescope applies an indirect imaging technique that uses the measurement of 30 visibilities, i.e., angular Fourier components of the solar flare X-ray source. Hence, the imaging problem for STIX consists of the Fourier inversion of the data measured by the instrument. In this work, we show that the visibility amplitude and phase calibration of 24 out of 30 STIX sub-collimators has reached a satisfactory level for scientific data exploitation and that a set of imaging methods is able to provide the first hard X-ray images of solar flares from Solar Orbiter. Four visibility-based image reconstruction methods and one count-based are applied to calibrated STIX observations of six events with GOES class between C4 and M4 that occurred in May 2021. The resulting reconstructions are compared to those provided by an optimization algorithm used for fitting the amplitudes of STIX visibilities. We show that the five imaging methods produce results morphologically consistent with the ones provided by the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory (SDO/AIA) in UV wavelengths. The χ 2 values and the parameters of the reconstructed sources are comparable between methods, thus confirming their robustness.
Collapse
Affiliation(s)
- Paolo Massa
- MIDA, Dipartimento di Matematica, Università di Genova, via Dodecaneso 35, 16146 Genova, Italy
| | - Andrea F. Battaglia
- University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch, Switzerland
- ETH Zürich, Rämistrasse 101, 8092 Zürich, Switzerland
| | - Anna Volpara
- MIDA, Dipartimento di Matematica, Università di Genova, via Dodecaneso 35, 16146 Genova, Italy
| | - Hannah Collier
- University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch, Switzerland
- ETH Zürich, Rämistrasse 101, 8092 Zürich, Switzerland
| | - Gordon J. Hurford
- University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch, Switzerland
| | - Matej Kuhar
- University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch, Switzerland
| | - Emma Perracchione
- Dipartimento di Scienze Matematiche “Giuseppe Luigi Lagrange”, Politecnico di Torino, Torino, Italy
| | - Sara Garbarino
- MIDA, Dipartimento di Matematica, Università di Genova, via Dodecaneso 35, 16146 Genova, Italy
| | - Anna Maria Massone
- MIDA, Dipartimento di Matematica, Università di Genova, via Dodecaneso 35, 16146 Genova, Italy
- CNR - SPIN Genova, via Dodecaneso 33, 16146 Genova, Italy
| | - Federico Benvenuto
- MIDA, Dipartimento di Matematica, Università di Genova, via Dodecaneso 35, 16146 Genova, Italy
| | - Frederic Schuller
- Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
| | - Alexander Warmuth
- Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
| | | | - Hualin Xiao
- University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch, Switzerland
| | - Shane A. Maloney
- Astrophysics Research Group, School of Physics, Trinity College Dublin, Dublin 2, Ireland
- School of Cosmic Physics, Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin, D02 XF86 Ireland
| | - Daniel F. Ryan
- University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch, Switzerland
| | - Michele Piana
- MIDA, Dipartimento di Matematica, Università di Genova, via Dodecaneso 35, 16146 Genova, Italy
- CNR - SPIN Genova, via Dodecaneso 33, 16146 Genova, Italy
| | - Säm Krucker
- University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch, Switzerland
- Space Sciences Laboratory, University of California, 7 Gauss Way, 94720 Berkeley, USA
| |
Collapse
|