Magnetospheric Accretion Models for the Hydrogen Emission Lines of T Tauri Stars

Abstract

Using a statistical equilibrium radiative transfer treatment, we examine the behavior of hydrogen emis-sion lines arising from the magnetospheric infall zones of classical T Tauri stars. Having calculated self-consistent line proÐles of the Balmer lines, Pab and Brc, we explore parameter space, examining the e ects of the magnetospheric gas temperature and size on the line Ñuxes. We compare model and observed line Ñuxes for the Balmer lines and Ðnd a good match using a relatively small range of param-eters. We are also able to match the observed Brc line proÐle of the embedded object WL 16, which supports the use of the infrared lines in studying magnetospheric infall even in the earliest stages of star formation. Finally, we discuss constraints on the physical parameters and the possibility of using the emission lines as accretion rate indicators.