This paper argues that the effect of Hawking radiation on an astrophysical black hole is not total evaporation of the black hole; rather there will always be a remnant. The key point is that the locus of emission of Hawking radiation is not the globally defined event horizon, but rather is just outside a timelike Marginal Outer Trapped Surface that is locally defined and lies inside the event horizon, close to the collapsing star. A spacelike singularity forms behind the event horizon, and most of the Hawking radiation ends up at this singularity rather than at infinity. Whether any Hawking radiation reaches infinity depends on the relation between the dynamic radiation emission surface and the event horizon, which is affected both by Cosmic Background Radiation and by back-reaction due to the Hawking radiation. From the outside view, even if radiation is seen as always being emitted, the black hole never evaporates away, rather its mass and entropy asymptote to finite non-zero limits. The argument is based on the broad nature of the processes at work, plus a careful delineation of the relevant causal domains; detailed calculations of back reaction effects are necessary in order to confirm this model and determine details of the outcome.
Date added: Fri, 18 Oct 13