• DOI:10.3847/1538-4357/835/2/228
• Corpus ID: 119480327

A Surface Density Perturbation in the TW Hydrae Disk at 95 au Traced by Molecular Emission

@article{Teague2017ASD,
  title={A Surface Density Perturbation in the TW Hydrae Disk at 95 au Traced by Molecular Emission},
  author={Richard Teague and Dmitry A Semenov and Uma Gorti and St{\'e}phane Guilloteau and Th. Henning and Tilman Birnstiel and A. Dutrey and Roy van Boekel and Edwige Chapillon},
  journal={The Astrophysical Journal},
  year={2017},
  volume={835}
}

• R. Teague, D. Semenov, +6 authors E. Chapillon
• Published 31 January 2017
• Physics, Geology
• The Astrophysical Journal

We present ALMA Cycle 2 observations at 0.″5 resolution of TW Hya of CS emission. The radial profile of the integrated line emission displays oscillatory features outward of 1.″5 ( au). A dip-like feature at 1.″6 is coincident in location, depth, and width with features observed in dust scattered light at near-infrared wavelengths. Using a thermochemical model indicative of TW Hya, gas-grain chemical modeling, and non-LTE radiative transfer, we demonstrate that such a feature can be reproduced with a surface density depression, consistent with the modeling performed for scattered-light observations of TW Hya. We further demonstrate that a gap in the dust distribution and dust opacity only cannot reproduce the observed CS feature. The outer enhancement at 3.″1 is identified as a region of intensified desorption due to enhanced penetration of the interstellar far-UV radiation at the exponential edge of the disk surface density, which intensifies the photochemical processing of gas and ices.