tokens: Work by M.Y., K.W., S.D.R., and N.J.T. was supported by NASA grant NNX10AH28G and further work by M.Y. and S.D.R. was supported by NSF grant 1055910. This work was performed in part at the Jet Propulsion Laboratory, California Institute of Technology. N.J.T. was supported by grant 13-OSS13-0114 from the NASA Origins of Solar Systems program. M.Y. was supported by a Continuing Fellowship from the University of Texas at Austin. We acknowledge helpful input from L. Cleeves, E. Bergin, E.F. van Dishoeck, K. Öberg, J. Huang, M. Ansdell, and A. Kraus. We are grateful to Feng Long et al. ( 2017 ) for sharing their paper in advance of publication, and Huang et al. for sharing processed ALMA data for our model comparison. Software: RADMC ( http://www.ita.uni-heidelberg.de/dullemond/software/radmc-3d/ ), LIME (Brinch Hogerheijde 2010 ).
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