New Tests of Magnetospheric Accretion in T Tauri Stars

We examine 3 analytic theories of magnetospheric accretion onto classical TTauri stars under the assumption that the magnetic field strength does not varyappreciably from star to star. From these investigations we derive predictedrelationships among the stellar mass, radius, rotation period, and diskaccretion rate. Data from 5 studies of the accretion parameters of CTTSs areused to test the predicted correlations. We generally find that the data do notdisplay the predicted correlations except for that predicted by the model ofShu et al. as detailed by Ostriker and Shu and extended here to includenon-dipole field topologies. Their identification of the trapped flux as animportant quantity in the model appears to be critical for reconciling theobserved data to the theory. While the data do generally support the extendedOstriker and Shu predictions, only one of the two studies for which therequisite data exist show the highest correlation when considering all therelevant parameters. This suggests great care must be taken when trying to useexisting observations to test the theory.Comment: 36 pages, including figure