http://www.aps.org/units/gpap/about/index.cfm
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.
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.
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."