Quasiperiodic acceleration of electrons by a plasmoid-driven shock in the solar atmosphere

Abstract

Cosmic rays and solar energetic particles may be accelerated to relativistic energies by shock waves in astrophysical plasmas. On the Sun, shocks and particle acceleration are often associated with the eruption of magnetized plasmoids, called coronal mass ejections (CMEs). However, the physical relationship between CMEs and shock particle acceleration is not well understood. Here, we use extreme ultraviolet, radio and white-light imaging of a solar eruptive event on 22 September 2011 to show that a CME-induced shock (Alfvén Mach number 2.4${}_{-0.8}^{+0.7}$) was coincident with a coronal wave and an intense metric radio burst generated by intermittent acceleration of electrons to kinetic energies of 2-46 keV (0.1-0.4 c). Our observations show that plasmoid-driven quasi-perpendicular shocks are capable of producing quasi-periodic acceleration of electrons, an effect consistent with a turbulent or rippled plasma shock surface.

References in corpus (4)

• Propagation of an Earth-directed coronal mass ejection in three dimensions
• Off-limb Solar Coronal Wavefronts From SDO/AIA EUV Observations - Implications For Particle Production
• Origin of Cosmic Rays
• Simulations of Electron Acceleration at Collisionless Shocks: The Effects of Surface Fluctuations

Cited by in corpus (8)

• Advances in Observing Various Coronal EUV Waves in the SDO Era and Their Seismological Applications (Invited Review)
• Understanding the Physical Nature of Coronal "EIT Waves"
• LOFAR tied-array imaging of Type III solar radio bursts
• A solar type II radio burst from CME-coronal ray interaction: simultaneous radio and EUV imaging
• Properties of a Coronal Shock Wave as A Driver of Early SEP Acceleration
• Bridging EUV and white-light observations to inspect the initiation phase of a "two-stage" solar eruptive event
• The Relation Between Large-Scale Coronal Propagating Fronts and Type II Radio Bursts
• Investigating the Kinematics of Coronal Mass Ejections with the Automated CORIMP Catalog