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).