Multiple Sources of Solar High-energy Protons
: Kocharov Leon, Omodei Nicola, Mishev Alexnder, Pesce-Rollins Melissa, Longo Fransesco, Yu Sijie, Gary Dale E, Vainio Rami, Usoskin Ilya
Publisher: IOP PUBLISHING LTD
: Bristol
: 2021
: Astrophysical Journal
: ASTROPHYSICAL JOURNAL
: ASTROPHYS J
: ARTN 12
: 915
: 9
: 0004-637X
: 0004-637X
DOI: https://doi.org/10.3847/1538-4357/abff57
: https://doi.org/10.3847/1538-4357/abff57
: https://research.utu.fi/converis/portal/detail/Publication/66841586
During the 24th solar cycle, the Fermi Large Area Telescope (LAT) has observed a total of 27 solar flares possessing delayed gamma-ray emission, including the exceptionally well-observed flare and coronal mass ejection (CME) on 2017 September 10. Based on the Fermi/LAT data, we plot, for the first time, maps of possible sources of the delayed >100 MeV gamma-ray emission of the 2017 September 10 event. The long-lasting gamma-ray emission is localized under the CME core. The gamma-ray spectrum exhibits intermittent changes in time, implying that more than one source of high-energy protons was formed during the flare-CME eruption. We find a good statistical correlation between the gamma-ray fluences of the Fermi/LAT-observed delayed events and the products of corresponding CME speed and the square root of the soft X-ray flare magnitude. Data support the idea that both flares and CMEs jointly contribute to the production of subrelativistic and relativistic protons near the Sun.