SIMBAD references

We model stationary profiles of physical quantities in a disk and its boundary layer around an accreting object using the relaxation method. We take into account the full energy equation with dissipation due to differential rotation and energy losses by radiation in the optically thick limit. We use the alpha prescription for the viscosity with a special treatment near the star according to previous works. We restrict ourselves to the subsonic case. We find that the system presents a twofold boundary layer: the usual dynamical one defined by the locus of the maximum rotation rate, and a thermal one, larger, the size of which is determined by an effective Prandtl number. Second, the presence of a radial flux at the inner boundary affects the energy balance. In particular, when energy is radiated into the star, the boundary layer is far from radiating half of the accretion luminosity. The spectral distribution of the emitted energy of the whole structure shows two components: in addition to the classical disk spectrum, there is a high energy part corresponding to the thermal boundary layer. The high energy excess due to the boundary layer can be either very strong or very weak, depending on the values of the model parameters. The more realistic spectral distribution corresponds to fairly low boundary layer luminosities. We apply this to the case of DF Tau.