Analysis of the approximate solutions of HII region expansion problem
The properties of interstellar gas produce significant effect on dynamic phenomena which occur at large heliocentric distances. HII region is a vivid example of the objects with extremely high radiation, where atoms of hydrogen are heated and ionized by ultraviolet radiation. This article deals with the HII region expansion. To study this process researches need effective methods that can provide information about quantitative and qualitative characteristics of the motion of the interstellar medium. In this article Cherny method is applied to a spherically symmetric case and Kompaneets method is used in the two dimensional axisymmetric case. The solutions obtained were compared to numerical calculations. The result of comparing shows good accuracy of the analytical solution. This method can be applied to solve real problems for specific HII regions.