Physics of the Injection of Particle Acceleration at Astrophysical, Heliospheric, and Laboratory Collisionless Shocks

led by Ryo Yamazaki and Shuichi Matsukiyo.


Collisionless shocks are ubiquitous in various astrophysical, heliospheric (or solar-terrestrial), and even laboratory phenomena. The aim of this team is to formulate a common understanding regarding the latest knowledge about the initial stage of the particle acceleration (or injection) process at collisionless shocks.

Recent gamma-ray and X-ray observations of supernova remnants have provided us with the detailed spatial and spectral structure of high-energy particles accelerated at astrophysical shocks, enabling us to discuss particle acceleration processes there. In-situ multi-spacecraft observations in the heliosphere have shown the spatio-temporal structures of shock transition region as well as the local distribution functions of thermal and non-thermal particles. In addition, laboratory astrophysics is now developing and collisionless shocks have come to be successfully reproduced in the laboratory.

The injection problem in the diffusive shock acceleration scenario is one of the important outstanding issues. In order to understand the injection mechanism(s) at collisionless shocks, we gather our knowledge of the latest observations, simulations, and theory, not only on astrophysical and heliospheric shocks but also on laboratory shocks. It is time now for researchers in different fields to sit together and discuss current status, latest achievements and issues, in each field.


Space Sciences (Astrophysics, Solar-Terrestrial and Heliospheric Physics, Laboratory Astrophysics)