Further Criteria for the Existence of Steady Line‐driven Winds

In Paper I, we showed that steady line-driven disk wind solutions can existby using "simple" models that mimic the disk environment. Here I extend theconcepts introduced in Paper I and discuss many details of the analysis of thesteady/unsteady nature of 1D line-driven winds. This work confirms the resultsand conclusions of Paper I, and is thus consistent with the steady nature ofthe 1D streamline line-driven disk wind models of Murray and collaborators andthe 2.5D line-driven disk wind models of Pereyra and collaborators. Whenincluding gas pressures effects, as is routinely done in time-dependentnumerical models, I find that the spatial dependence of the nozzle functioncontinues to play a key role in determining the steady/unsteady nature ofsupersonic line-driven wind solutions. I show here that theexistence/nonexistence of local wind solutions can be proved through the nozzlefunction without integrating the equation of motion. This work sets a detailedframework with which we will analyze, in a following paper, more realisticmodels than the "simple" models of Paper I.Comment: 30 pages, 5 figures, accepted for publication by The Astrophysical Journa