Journal
ASTROPHYSICAL JOURNAL LETTERS
Volume 763, Issue 1, Pages -Publisher
IOP PUBLISHING LTD
DOI: 10.1088/2041-8205/763/1/L5
Keywords
acceleration of particles; magnetic reconnection; solar wind; Sun: corona; Sun: flares; Sun: heliosphere
Categories
Funding
- NSF [AGS1202330]
- NASA [APL-975268, NNX08AV87G]
- Directorate For Geosciences
- Div Atmospheric & Geospace Sciences [1202330] Funding Source: National Science Foundation
- NASA [94116, NNX08AV87G] Funding Source: Federal RePORTER
Ask authors/readers for more resources
Power-law distributions are a near-universal feature of energetic particle spectra in the heliosphere. Anomalous cosmic rays (ACRs), super-Alfvenic ions in the solar wind, and the hardest energetic electron spectra in flares all have energy fluxes with power laws that depend on energy E approximately as E-1.5. We present a new model of particle acceleration in systems with a bath of merging magnetic islands that self-consistently describes the development of velocity-space anisotropy parallel and perpendicular to the local magnetic field and includes the self-consistent feedback of pressure anisotropy on the merging dynamics. By including pitch-angle scattering we obtain an equation for the omnidirectional particle distribution f(v, t) that is solved in closed form to reveal v(-5) (corresponding to an energy flux varying as E-1.5) as a near-universal solution as long as the characteristic acceleration time is short compared with the characteristic loss time. In such a state, the total energy in the energetic particles reaches parity with the remaining magnetic free energy. More generally, the resulting transport equation can serve as the basis for calculating the distribution of energetic particles resulting from reconnection in large-scale inhomogeneous systems.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available