Open AccessMultiple Sources of Solar High-energy Protons
Author(s) -
L. G. Kocharov,
N. Omodei,
Alexander Mishev,
M. Pesce-Rollins,
F. Longo,
Sijie Yu,
Dale E. Gary,
Rami Vainio,
Ilya Usoskin
Publication year - 2021
Publication title -
astrophysical journal/the astrophysical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.376
H-Index - 489
eISSN - 1538-4357
pISSN - 0004-637X
DOI - 10.3847/1538-4357/abff57
Subject(s) - physics , flare , coronal mass ejection , fermi gamma ray space telescope , astrophysics , solar flare , astronomy , telescope , gamma ray , nuclear physics , plasma , solar wind
During the 24th solar cycle, the Fermi Large Area Telescope (LAT) has observed a total of 27 solar flares possessing delayed γ -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 γ -ray emission of the 2017 September 10 event. The long-lasting γ -ray emission is localized under the CME core. The γ -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 γ -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.