= Radiative-zero disk surface
For a constant-opacity, gas-pressure-supported radiative disk surface at $z=H$, imposing $p=T=0$ does not impose $F=0$. If the outgoing surface <flux> is finite and positive, dividing hydrostatic balance by the <temperature> gradient gives $dp/dT\sim16\sigma\Omega^2HT^3/(3\kappa F_s)$. Consequently $p\propto T^4$, $\rho\propto T^3$, and the diffusion equation gives $T\propto H-z$. Thus the <mass density> also vanishes regularly while the surface radiates a finite <flux>. This ideal boundary replaces the finite-temperature photospheric transition; its accuracy is not controlled solely by the disk aspect ratio.
// Target: astrophysics.bigb
Back to article page
