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arXiv · 1409.1390

Surface Geometry of Protoplanetary Disks Inferred From Near-Infrared Imaging Polarimetry

Abstract

We present a new method of analysis for determining the surface geometry of five protoplanetary disks observed with near-infrared imaging polarimetry using Subaru-HiCIAO. Using as inputs the observed distribution of polarized intensity (PI), disk inclination, assumed properties for dust scattering, and other reasonable approximations, we calculate a differential equation to derive the surface geometry. This equation is numerically integrated along the distance from the star at a given position angle. We show that, using these approximations, the local maxima in the PI distribution of spiral arms (SAO 206462, MWC 758) and rings (2MASS J16042165-2130284, PDS 70) are associated with local concave-up structures on the disk surface. We also show that the observed presence of an inner gap in scattered light still allows the possibility of a disk surface that is parallel to the light path from the star, or a disk that is shadowed by structures in the inner radii. Our analysis for rings does not show the presence of a vertical inner wall as often assumed in studies of disks with an inner gap. Finally, we summarize the implications of spiral and ring structures as potential signatures of ongoing planet formation.

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Michihiro Takami, Yasuhiro Hasegawa, Takayuki Muto, Pin-Gao Gu, Ruobing Dong, Jennifer L. Karr, Jun Hashimoto, Nobuyuki Kusakabe, Edwige Chapillon, Ya-Wen Tang, Youchi Itoh, Joseph Carson, Katherine B. Follette, Satoshi Mayama, Michael Sitko, Markus Janson, Carol A. Grady, Tomoyuki Kudo, Eiji Akiyama, Jungmi Kwon, Yasuhiro Takahashi, Takuya Suenaga, Lyu Abe, Wolfgang Brandner, Timothy D. Brandt, Thayne Currie, Sebastian E. Egner, Markus Feldt, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Saeko Hayashi, Thomas Henning, Klaus W. Hodapp, Mitsuhiko Honda, Miki Ishii, Masanori Iye, Ryo Kandori, Gillian R. Knapp, Masayuki Kuzuhara, Michael W. McElwain, Taro Matsuo, Shoken Miyama, Jun-Ichi Morino, Amaya Moro-Martin, Tetsuo Nishimura, Tae-Soo Pyo, Eugene Serabyn, Hiroshi Suto, Ryuji Suzuki, Naruhisa Takato, Hiroshi Terada, Christian Thalmann, Daigo Tomono, Edwin L. Turner, John P. Wisniewski, Makoto Watanabe, Toru Yamada, Hideki Takami, Tomonori Usuda, Motohide Tamura. 2014-09-04. Surface Geometry of Protoplanetary Disks Inferred From Near-Infrared Imaging Polarimetry. https://doi.org/10.1088/0004-637x/795/1/71

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