  A physical analysis and mathematical formulation of the structure of an
accretion shock wave in the case of young stars are given. Some results are
presented, and the dependence of the structure of the shock on various
parameters is investigated. In the general case, the relative intensities and
profiles of lines in the spectra of T Tauri stars should depend on the velocity
and density of the infalling gas, as well as on the accretion geometry. The
calculation results may serve as a base for elucidating the nature of the
activity of young stars.
