抄録
The Geotail high-energy particle instruments have observed cosmic-ray particles in the energy range from 3 MeV n-1 to 150 MeV n-1 at 1 AU during the period 1992 September-1995 August. A remarkable enhancement of anomalous cosmic-ray (ACR) N, O, Ne, and C is observed during the period. A measurable enhancement of the sulfur flux below about 20 MeV n-1 was observed. This is the first evidence showing the existence of sulfur in the anomalous component. The flux increase of anomalous sulfur, with a first ionization potential (FIP) of 10.4 eV, is smaller than that of ACR carbon with an FIP of 11.3 eV and much smaller than those of high-FIP elements, which suggests that the fractions of neutral carbon and sulfur atoms are significantly low in the very local interstellar medium.
本文言語 | English |
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ジャーナル | Astrophysical Journal |
巻 | 477 |
号 | 2 PART II |
出版ステータス | Published - 1997 |
外部発表 | はい |
ASJC Scopus subject areas
- 宇宙惑星科学