Line and continuum radiative transfer modelling of AA Tau

Abstract

We present photometric and spectroscopic models of the Classical T Tauri star AA Tau. Photometric and spectroscopic variability present in observations of AA Tau is attributed to a magnetically induced warp in the accretion disc, periodically occulting the photosphere on an 8.2--day timescale. Emission line profiles show signatures of both infall, attributed to magnetospherically accreting material, and outflow. Using the radiative transfer code TORUS, we have investigated the geometry and kinematics of AA Tau's circumstellar disc and outflow, which is modelled here as a disc wind. Photometric models have been used to constrain the aspect ratio of the disc, the offset angle of the magnetosphere dipole with respect to the stellar rotation axis, and the inner radius of the circumstellar disc. Spectroscopic models have been used to constrain the wind and magnetosphere temperatures, wind acceleration parameter, and mass loss rate. We find observations are best fitted by models with a mass accretion rate of $5\times 10^{-9}$ M${}_{\odot }$ yr${}^{-1}$, a dipole offset of between $10^{\circ }$ and $20^{\circ }$, a magnetosphere that truncates the disc from 5.2 to 8.8 R${}_{\star }$, a mass-loss-rate to accretion-rate ratio of ~ 0.1, a magnetosphere temperature of 8500 -- 9000 K, and a disc wind temperature of 8000 K.

22 pages, 32 figures, 4 tables. Accepted by MNRAS. V3: Corrected typo

References in corpus (10)

• The Magnetic Fields of Classical T Tauri Stars
• Which jet launching mechanism(s) in TTauri stars?
• Magnetospheric accretion-ejection processes in the classical T Tauri star AA
• Probing T Tauri Accretion and Outflow with 1 Micron Spectroscopy
• On the formation of H-alpha line emission around classical T Tauri stars
• Results of the ROTOR-program. I. The long-term photometric variability of classical T Tauri stars
• The origin of hydrogen line emission for five Herbig Ae/Be stars spatially resolved by VLTI/AMBER spectro-interferometry
• Modeling T Tauri Winds from He I 10830 Profiles
• Emission-line profile modelling of structured T Tauri magnetospheres
• Rotation Effects in Classical T Tauri Stars

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• Characteristics of small protoplanetary disc warps in kinematic observations
• Spectroscopic and interferometric signatures of magnetospheric accretion in young stars
• Pre-main Sequence Brackett Emitters in the APOGEE DR17 Catalog: Line Strengths and Physical Properties of Accretion Columns
• Potential sublimating exocomets around the young star PDS 70