Ryuichi Kurosawa, Marina M. Romanova
We present the emission line profile models of hydrogen and helium based on the results from axisymmetric magnetohydrodynamics (MHD) simulations of the wind formed near the disk-magnetosphere boundary of classical T Tauri stars (CTTSs). We extend the previous outflow models of `the conical wind' by Romanova et al. to include a well defined magnetospheric accretion funnel flow which is essential for modelling the optical and near-infrared hydrogen and helium lines of CTTSs. Our MHD model shows outflows in conical shape with a half opening angle about 35 degrees. The flow properties such as the maximum outflow speed in the conical wind, maximum inflow speed in the accretion funnel, mass-accretion and mass-loss rates are comparable to those found in a typical CTTS. The density, velocity and temperature from the MHD simulations are used in a separate radiative transfer model to predict the line profiles and test the consistency of the MHD models with observations. The line profiles are computed with various combinations of X-ray luminosities, temperatures of X-ray emitting plasma, and inclination angles. A rich diversity of line profile morphology is found, and many of the model profiles are very similar to those found in observations. We find the line equivalent widths (EWs) of He I (10830), He I (5876), H-alpha, H-beta, Pa-beta and Pa-gamma predicted by the model are mostly within the ranges of the observed values; however, the model tends to underestimate the EWs for some of the lines when compared to the average EW values found in observations. The model well reproduces a relatively narrow and low-velocity blueshifted absorption component in He I (10830), which are often seen in observations.
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http://arxiv.org/abs/1203.5154
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