Hydrogen line emission from accretion disks. II. A grid of models with applications to the optically thin regions of disks

We report the results of a grid of non-Local thermodynamic equilibrium (LTE) accretion disk models. These models were computed by a program which calculates the radiative transfer at positions in an accretion disk characterized by a local temperature and midplane density. The models cover a range of temperatures from 4000 to 15 000 K, and a range of densities which take the local disk models from being optically thick to optically thin. The models provide information on Balmer line strengths and profiles, and on the efficiency with which the disk cools by continuous and line emission. As found in our earlier paper, the Balmer emission lines show deep absorption cores. The efficiency of cooling of the disk is used to construct a steady-state α-disk program for the optically thin regions of accretion disk. The models generated by this program are compared with previous LTE models. Line profiles from the disk as a whole were calculated using one of these α-disk models.