Anomalous cosmic ray oxygen and neon (∼2.4 MeV/nucl) at high southern heliolatitudes

Abstract

We report measurements of the anomalous oxygen and neon as measured with the HI‐SCALE instrument on Ulysses at high southern heliolatitudes. Using both energy spectral features and C/O ratios, 2.0–2.8 MeV/nucl anomalous O is not distinguishable below a latitude of ∼40°S. The heliolatitude gradient is found to be +0.06±0.50% / degree for the heliolatitude range 40°S to 80°S for an assumed radial gradient of 15% per AU. For the assumption of no radial gradient, the heliolatitude gradient is 0.39±0.42%/degree. The O flux at this energy is ∼2 × 10−8/(cm² sr s MeV/nucl); the Ne flux is ∼5 × 10−9/(cm² sr s MeV/nucl).