Space and Astroplasma Physics
Our main science objective is to study fundamental processes in plasma universe by focusing on particle acceleration, plasma heating and mixing in shock waves and magnetic reconnection and so on. These processes can be observed in many different plasma circumstances from the earth’s magnetosphere to the solar corona and the astrophysical phenomena. There are many differences not only in the spatial scale and energy but also in the topology and boundary conditions, yet there have many similarity in fundamental physics. During the last decade, the solar system has become recognized as the primary plasma laboratory in which plasma processes of great generality can be studied. Ubiquity of plasma phenomena in universe leads us to get further insight into the physics of plasma dynamics. We are studying on plasma phenomena not only in our solar system but also in our universe, by paying special attention to those fundamental plasma processes.
Our recent topics are as follows: (1) Research on shock waves: Cosmic rays are high-energy particles coming from universe, yet their origin is not fully understood. Among a wide variety of potential sources such as supernovae, active galactic nuclei, quasars, and gamma-ray bursts, the physics of collisionless shock waves are believed to be a most important key elements of high energy particle acceleration. We are investigating the particle acceleration in collisionless shock waves by using super-computer simulations and the satellite observation data. (2) Research on magnetic reconnection: Magnetic reconnection is a very important plasma process in universe in which the magnetic topology is rearranged and magnetic energy is converted to plasma heating and acceleration. It may be a candidate of cosmic rays as well. We are extensively working on the satellite data analysis together with the computer simulation to understand how and where the charged particles gain their energy during the magnetic energy release of reconnection. (3) Research on other plasma processes: In addition to shock waves and magnetic reconnection, we also work on many other plasma phenomena and fundamental processes. Those key words of our resent research are as follows: accretion disk, turbulence and nonlinear waves, relativistic plasmas, and dust plasma.
1. M. Hoshino, Energy Partition between Ion and Electron of Collisionless Magnetic Reconnection, Astrophys. J. Letters, doi:10.3847/2041-8213/aaef3a (2018)
2. M. Pohl, M. Hoshino, and J. Niemiec, PIC simulation methods for cosmic radiation and plasma instabilities, Progress in Particle and Nuclear Physics, https://doi.org/10.1016/j.ppnp.2019.103751 (2019)
3. M. Hoshino, Angular momentum transport and particle acceleration during magnetorotational instability in a kinetic accretion disk, Physical Review Letters, DOI:10.1103/PhysRevLett.114.061101 (2015)