Composition and energy spectra of anomalous cosmic rays observed by the geotail satellite

Nobuyuki Hasebe*, K. Kondoh, Y. Mishima, T. Doke, J. Kikuchi, T. Hayashi, T. Takashima, M. Kobayashi, N. Takehana, H. Shirai, T. Yanagimachi, A. Nakamoto, H. Murakami, K. Nagata, T. Kohno, K. Munakata, C. Kato, S. Yanagita, Y. Yamada, M. EharaT. Kashiwagi, Y. Muraki, T. Koi, J. Sequeiros, J. Medina, B. Wilken

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


The composition and energy spectra of anomalous cosmic-rays (ACRs) in the energies 6 - 200 MeV/n have been measured during the period from September 1992 to August 1995 using the High Energy Particle instrument onboard the GEOTAIL satellite orbiting at 1 AU. A remarkable enhancement of ACR N, O, Ne and Ar is observed during the period. A flux enhancement of anomalous argon at 1 AU is confirmed by the GEOTAIL satellite. The first possible evidence for the emergence of a measurable sulfur component in ACR below about 20 MeV/n is found. The flux increase of anomalous sulfur with 10.4 eV FIP is smaller than that of ACR carbon with 11.3 eV FIP, and much smaller than those of high FIP elements, which suggests that the fraction of neutral carbon and sulfur atoms is significantly lower in the very local interstellar medium.

Original languageEnglish
Pages (from-to)813-816
Number of pages4
JournalAdvances in Space Research
Issue number5
Publication statusPublished - 1997
Externally publishedYes

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics


Dive into the research topics of 'Composition and energy spectra of anomalous cosmic rays observed by the geotail satellite'. Together they form a unique fingerprint.

Cite this