When
3:30 p.m., Oct. 27, 2009
Where
Kuiper Space Sciences Building 308
Professor Joe Giacalone is the scheduled speaker.
The solar system is permeated by high-energy charged particles moving in response to electromagnetic fields in space that originate at the Sun and are carried outwards by the solar wind. These energetic particles come from a variety of sources, including those beyond our solar system, presumably supernova explosions, heliospheric flows and shocks, and near the Sun, often in violent solar explosions. In addition to their intrinsic interest, the particles themselves are useful probes of these remote regions of space, some of which are inaccessible to spacecraft. They provide information regarding both the medium through which they propagate, and also of processes involved in their acceleration. In this talk I will discuss recent insights into the origin and acceleration of energetic charged-particles in the solar system. I will argue that most of the energetic particles we see were accelerated by collisionless shocks, particularly those that move normal to a magnetic field. Several examples will be discussed, including acceleration by shocks associated with coronal mass ejections, and supernova blast waves.
The solar system is permeated by high-energy charged particles moving in response to electromagnetic fields in space that originate at the Sun and are carried outwards by the solar wind. These energetic particles come from a variety of sources, including those beyond our solar system, presumably supernova explosions, heliospheric flows and shocks, and near the Sun, often in violent solar explosions. In addition to their intrinsic interest, the particles themselves are useful probes of these remote regions of space, some of which are inaccessible to spacecraft. They provide information regarding both the medium through which they propagate, and also of processes involved in their acceleration. In this talk I will discuss recent insights into the origin and acceleration of energetic charged-particles in the solar system. I will argue that most of the energetic particles we see were accelerated by collisionless shocks, particularly those that move normal to a magnetic field. Several examples will be discussed, including acceleration by shocks associated with coronal mass ejections, and supernova blast waves.
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