[P-PS15] New developments of planetary sciences with ALMA

[PPS15-04] ALMA Observations of a Gap and a Ring in the Protoplanetary Disk around TW Hya

*Hideko Nomura¹, Takashi Tsukagoshi², Ryohei Kawabe³, Daiki Ishimoto^4,1, Satoshi Okuzumi¹, Takayuki Muto⁵, Kazuhiro Kanagawa⁶, Shigeru Ida⁷, Catherine Walsh⁸, Tom J Millar⁹, Bai Xue-Ning¹⁰ (1.Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2.College of Science, Ibaraki University, 3.National Astronomical Observatory of Japan, 4.Department of Astronomy, Graduate School of Science, Kyoto University, 5.Division of Liberal Arts, Kogakuin University, 6.University of Szczecin, 7.Earth-Life Science Institute, Tokyo Institute of Technology, 8.Leiden Observatory, Leiden University, 9.Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, 10.Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics)

Keywords:protoplanetary disks, dust continuum emission, gap and ring

We report the first detection of a gap and a ring in 336GHz dust continuum emission from the protoplanetary disk around TW Hya, using the Atacama Large Millimeter/Submillimeter Array (ALMA). The gap and ring are located at around 25 and 41 AU from the central star, respectively, and are associated with the CO snowline at ~ 30AU. The gap has a radial width of less than 15AU and a mass deficit of more than 23%, taking into account that the observations are limited to an angular resolution of ~ 15AU. The observed gap could be caused by gravitational interaction between the disk gas and a planet with a mass less than super-Neptune (2M_Neptune), or result from destruction of large dust aggregates due to the sintering of CO ice.