title: Particle acceleration by a solar flare termination shock.
abstract: Solar flares--the most powerful explosions in the solar system--are also efficient particle accelerators, capable of energizing a large number of charged particles to relativistic speeds. A termination shock is often invoked in the standard model of solar flares as a possible driver for particle acceleration, yet its existence and role have remained controversial. We present observations of a solar flare termination shock and trace its morphology and dynamics using high-cadence radio imaging spectroscopy. We show that a disruption of the shock coincides with an abrupt reduction of the energetic electron population. The observed properties of the shock are well reproduced by simulations. These results strongly suggest that a termination shock is responsible, at least in part, for accelerating energetic electrons in solar flares.
authors.affiliation: Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA. bin.chen@njit.edu.
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.affiliation: National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA.
authors.forename: Timothy S
authors.initials: TS
authors.lastname: Bastian
authors.affiliation: Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA.
authors.forename: Chengcai
authors.initials: C
authors.lastname: Shen
authors.affiliation: New Jersey Institute of Technology, 323 Martin Luther King Boulevard, Newark, NJ 07102, USA.
authors.forename: Dale E
authors.initials: DE
authors.lastname: Gary
authors.affiliation: University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720, USA. University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch, Switzerland.
authors.forename: Säm
authors.initials: S
authors.lastname: Krucker
authors.affiliation: University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720, USA. University of Minnesota, Twin Cities, 116 Church Street SE, Minneapolis, MN 55455, USA.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Glesener