Rationale and Background
It has been recognized for the last four decades that the physics of plasmas plays a crucial role in several astrophysical phenomena. Among the ranks of astrophysicists, one can identify several outstanding plasma astrophysicists who through the years have incorporated fundamental plasma physics concepts in the elucidation of astrophysical observations. It is fair to assert, however, that the plasma astrophysicists have been a fairly small and select group in the much larger milieu of astrophysicists. Astrophysics being the vast subject it is, including as it does astronomers, atomic and molecular physicists, cosmologists, high-energy physicists, hydrodynamicists, nonlinear dynamicists and relativists, the recognition that an understanding of the physics of magnetized plasmas is not only invaluable but may be essential in some cases for a proper explanation of observations has been relatively slow. In the meantime, the field of plasma physics, with strong impetus from fusion, laboratory and space plasma science has grown to significant maturity. In recent years, it has become increasingly clear that this mature body of knowledge is likely to have a significant impact in the eventual resolution of some of the outstanding questions in astrophysics. We cite a few examples: the origin and dynamics of magnetic fields is astrophysical systems ("the dynamo problem"), the mysteries of x-ray emitting coronas and the role of magnetic reconnection, the acceleration of charged particles and cosmic rays, the ejection of winds and jets from highly-evolved stars with convecting outer layers and supernova remnants, and the turbulence of the magnetized plasma in the interstellar medium and the solar wind.
Despite the identification of a rich class of physical problems of mutual interest, the plasma physics and astrophysics communities have remained, for the most part, quite distinct, with different societies and memberships, conferences and archival journals. A primary rationale for the formation of a Topical Group in Plasma Astrophysics (within the APS) is to build a bridge between the two communities that will promote the advancement and diffusion of knowledge in both communities. We believe that the Topical Group will provide a new umbrella for interdisciplinary activity that will enrich both fields and extend the traditional boundaries of astrophysics and plasma physics.
The urgent need to create this Topical Group was identified by the small but growing membership of the informal Plasma Astrophysics Working Group (PAWG) that met regularly during the annual APS meeting of the Division of Plasma Physics (DPP). Apart from the reasons already mentioned above, participants of the PAWG suggested several other compelling reasons for the formation of the Topical Group: that it will lead to the genuine sharing of knowledge based in fundamental plasma physics and stripped of the jargon that often inhibits communication between the different communities; that it will provide a natural home for people who do not presently feel at home in the DPP or even are members of the APS; that the Topical Group will make it easier for plasma astrophysics to become an integral and visible part of the APS meetings and to elect APS Fellows in this important and growing area of research; that it will give focus for research funding by the National Science Foundation and the Department of Energy, and so forth.
The Topical Group was approved by the APS Council on November 15, 1998 with the following mission statement:
"The principal objective of this Topical Group shall be the advancement and diffusion of plasma astrophysics---an interdisciplinary body of knowledge that seeks common ground between plasma physics and astrophysics, and involves the application of fundamental concepts of plasma physics to the solution of outstanding problems in astrophysics."
Those who wish to join the Topical Group can do so easily online or by checking the appropriate line-item in the annual billing statement. If you have questions or comments, please send them to the Chair.