Disk Wind as a Source of the Photometric Activity of Young Stars in the Optical and Infrared Spectral Ranges

Abstract

The influence of the dust component of a magnetocentrifugal disk wind on the circumstellar extinction and the infrared thermal radiation of T Tauri stars is investigated. The wind models from Safier’s papers, which are analytical approximations of the solutions for a magnetocentrifugal dusty disk wind, are taken as a basis. An accretion spot whose luminosity is scaled in accordance with the accretion rate and stellar parameters is added to the stellar spectrum. The radiative transfer in the wind and the circumstellar disk has been simulated by the Monte Carlo method using the RADMC3D code. The results of our simulations are applied to T Tauri stars with UX Ori-type variability. We show that when such stars are observed at a small angle to the disk plane, an increase in the accretion rate can cause an optical fading of the stars and, simultaneously, an enhancement of their infrared radiation. We also show that the results of our simulations are sensitive to the magnetic field topology in the disk in the wind formation zone. The results of our calculations are discussed in connection with the observations of deep minima in the T Tauri stars V1184 Tau and RW Aur accompanied by an enhancement of their radiation in the near-infrared spectral range. In the Conclusions we briefly discuss alternative mechanisms for the uplift of dust above the disk capable of causing an enhancement of the infrared radiation from young stars.