The Spatial Distribution of Particles Accelerated by Coronal Mass Ejection--driven Shocks
Abstract
We use multispacecraft observations to examine the spatial and temporal distributions of energetic particles accelerated by shock waves driven by coronal mass ejections from the Sun. The behavior of the intensity time profiles ahead of the shock can depend strongly on the longitude of the point where the observer's magnetic flux tube connects to the shock, relative to the nose of the shock where acceleration is strongest. Particle intensities can increase (decrease) with time as this point swings eastward through ≥ 50° toward (away from) the shock nose because of solar rotation. Well behind the shock, intensities are often constant with longitude and the intensities of these quasi-trapped particles at all energies decrease continuously with time over many days as their containment volume expands. Delayed proton events are produced when shocks expand into slow solar wind so they suddenly encounter an observer's field line far from the Sun. Sunward flows are seen when the shock passes over the observer or when it suddenly strikes his field line at radial distances out beyond him.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1996
- DOI:
- 10.1086/177525
- Bibcode:
- 1996ApJ...466..473R
- Keywords:
-
- ACCELERATION OF PARTICLES;
- SHOCK WAVES;
- SUN: CORONA;
- SUN: PARTICLE EMISSION