High-resolution near-infrared polarimetry of a circumstellar disk around UXTauA

Ryoko Tanii, Yoichi Itoh, Tomoyuki Kudo, Tomonori Hioki, Yumiko Oasa, Ranjan Gupta, Asoke K. Sen, John P. Wisniewski, Takayuki Muto, Carol A. Grady, Jun Hashimoto, Misato Fukagawa, Satoshi Mayama, Jeremy Hornbeck, Michael L. Sitko, Ray W. Russell, Chelsea Werren, Michel Cure, Thayne Currie, Nagayoshi OhashiYoshiko Okamoto, Munetake Momose, Mitsuhiko Honda, Shu Ichi Inutsuka, Taku Takeuchi, Ruobing Dong, Lyu Abe, Wolfgang Brandner, Timothy D. Brandt, Joseph Carson, Sebastian E. Egner, Markus Feldt, Tsubasa Fukue, Miwa Goto, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Saeko S. Hayashi, Thomas Henning, Klaus W. Hodapp, Miki Ishii, Masanori Iye, Markus Janson, Ryo Kandori, Gillian R. Knapp, Nobuhiko Kusakabe, Masayuki Kuzuhara, Taro Matsuo, Michael W. Mcelwain, Shoken Miyama, Jun Ichi Morino, Amaya Moro-Martin, Tetsuro Nishimura, Tae Soo Pyo, Eugene Serabyn, Hiroshi Suto, Ryuji Suzuki, Michihiro Takami, Naruhisa Takato, Hiroshi Terada, Christian Thalmann, Daigo Tomono, Edwin L. Turner, Makoto Watanabe, Toru Yamada, Hideki Takami, Tomonori Usuda, Motohide Tamura

Research output: Contribution to journalArticle

29 Scopus citations

Abstract

We present H-band polarimetric imagery of UXTauA taken with HiCIAO/AO188 on the Subaru Telescope. UXTauA has been classified as a pre-transitional disk object, with a gap structure separating its inner and outer disks. Our imagery taken with the 0. ''15 (21AU) radius coronagraphic mask has revealed a strongly polarized circumstellar disk surrounding UXTauA, which extends to 120AU, at a spatial resolution of 0. ''1 (14AU). It is inclined by 46 ± 2, since the west side is nearest. Although SED modeling and sub-millimeter imagery have suggested the presence of a gap in the disk, with the inner edge of the outer disk estimated to be located at 25-30AU, we detect no evidence of a gap at the limit of our inner working angle (23AU) at the near-infrared wavelength. We attribute the observed strong polarization (up to 66%) to light scattering by dust grains in the disk. However, neither polarization models of the circumstellar disk based on Rayleigh-scattering nor Mie-scattering approximations were consistent with the observed azimuthal profile of the polarization degrees of the disk. Instead, a geometric optics model of the disk with nonspherical grains with radii of 30μm is consistent with the observed profile. We suggest that the dust grains have experienced frequent collisional coagulations, and have grown in the circumstellar disk of UXTauA.

Original languageEnglish (US)
Article number124
JournalPublications of the Astronomical Society of Japan
Volume64
Issue number6
DOIs
StatePublished - Dec 25 2012
Externally publishedYes

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Keywords

  • Stars: planetary systems: protoplanetary disk
  • Techniques: high angular resolution
  • Techniques: polarimetric

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Tanii, R., Itoh, Y., Kudo, T., Hioki, T., Oasa, Y., Gupta, R., Sen, A. K., Wisniewski, J. P., Muto, T., Grady, C. A., Hashimoto, J., Fukagawa, M., Mayama, S., Hornbeck, J., Sitko, M. L., Russell, R. W., Werren, C., Cure, M., Currie, T., ... Tamura, M. (2012). High-resolution near-infrared polarimetry of a circumstellar disk around UXTauA. Publications of the Astronomical Society of Japan, 64(6), [124]. https://doi.org/10.1093/pasj/64.6.124