Anomaly in the quiet-time helium spectrum at 1 MeV per nucleon.
Abstract
The IMP-8 satellite observed (in 1974-1975) an unexpected hump in the solar helium spectrum between 0.6 and about 3 MeV per nucleon and an enhanced helium abundance of up to 70 MeV per nucleon. The energy spectrum of helium below 0.6 MeV per nucleon was consistent with the proton spectrum below 1.5 MeV, while the proton-to-alpha ratio was about 30. The origin of this anomalous low-energy, quiet-time helium is as yet undecided. The alpha particles could be of solar origin, could have been accelerated in the heliosphere or could be of galactic origin.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1976
- DOI:
- 10.1086/154240
- Bibcode:
- 1976ApJ...204..920G
- Keywords:
-
- Abundance;
- Energy Spectra;
- Helium;
- Solar Spectra;
- Anomalies;
- Galactic Radiation;
- Imp;
- Line Spectra;
- Proton Energy;
- Satellite Observation;
- Solar Activity;
- Solar Cosmic Rays;
- Time Dependence;
- Solar Physics