Abstract

Contributed Talk - Splinter Plasma

Tuesday, 19 September 2017, 15:05   (D+E+F MPS)

Origins of ³He-Rich Solar Energetic Particles

R. Bu\vcík^1,2, N.-H. Chen³, J. F. Drake⁴, D. Eichler⁵, G. D. Fleishman⁶, G. C. Ho⁷, N. L. S. Jeffrey⁸, S. Kahler⁹, R. Kumar^5,10, S. Liu¹¹, N. V. Nitta¹², M. E. Wiedenbeck^13
1Max Planck Institute for Solar System Research, Göttingen, Germany
²Institute for Astrophysics, University of Göttingen, Göttingen, Germany
³Korea Astronomy and Space Science Institute, Daejeon, Republic of Korea
⁴Institute for Physical Science and Technology, University of Maryland, College Park, USA
⁵Department of Physics, Ben-Gurion University, Be'er-Sheva, Israel
⁶Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, USA
⁷Applied Physics Laboratory, Johns Hopkins University, Laurel, USA
⁸School of Physics & Astronomy, University of Glasgow, Glasgow, UK
⁹U.S. Air Force Research Laboratory, Kirtland AFB, USA
¹⁰Department of Astrophysical Sciences, Princeton University, Princeton, USA
¹¹Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, China
¹²Lockheed Martin Advanced Technology Center, Palo Alto, USA
¹³Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA

Particle acceleration in solar or stellar flares remains an outstanding problem in astrophysics. Solar flare energetic particles are characterized by a peculiar chemical composition with the rare elements like ³He or ultra-heavy ions enhanced by factors up to ten thousand above their thermal abundances. Such huge fractionation is unknown in any other site in the Universe. The solar sources of these events have been commonly associated with coronal jets, believed to be a signature of magnetic reconnection involving field lines open to interplanetary space. With the improved resolution of extreme ultraviolet imaging observations, the ³He-rich sources have been systematically analyzed in the last decade. Alongside with a modeling effort, which now focuses on various ion species, significant progress has been achieved in the understanding of the phenomena. Observational predictions of various models of ion acceleration in solar flares are discussed.