This is a white paper submitted to the Stars and Stellar Evolution (SSE) Science Frontier Panel (SFP) of the NRCs Astronomy and Astrophysics 2010 Decadal Survey. The white paper is endorsed by the American Physical Societys (APS) Topical Group on Plasma Astrophysics (GPAP).
We point out that a conventional construction placed upon observations of accreting black holes, in which their nonthermal X-ray spectra are produced by inverse comptonization in a coronal plasma, suggests that the plasma is marginally collisionless.
Recent developments in plasma physics indicate that fast reconnection takes place only in collisionless plasmas. As has recently been suggested for the Suns corona, such marginal states may result from a combination of energy balance and the requirements of fast magnetic reconnection.
