Radial decoupling of small and large dust grains in the transitional disk RX J1615.3-3255

¹ Kapteyn Astronomical Institute, University of Groningen, Postbus 800, 9700 AV, Groningen, The Netherlands
e-mail: kooistra@astro.rug.nl
² Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602 Aichi, Japan
³ Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
⁴ College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito, 310-8512 Ibaraki, Japan
⁵ Subaru Telescope, 650 North A’ohoku Place, Hilo, HI 96720, USA
⁶ Astrobiology Center of NINS, 2-21-1, Osawa, Mitaka, 181-8588 Tokyo, Japan
⁷ Laboratoire Lagrange (UMR 7293), Université de Nice-Sophia Antipolis, CNRS, Observatoire de la Côte d’Azur, 28 avenue Valrose, 06108 Nice Cedex 2, France
⁸ Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany
⁹ Astrophysics Department, Institute for Advanced Study, Princeton, NJ, USA
¹⁰ Department of Physics and Astronomy, College of Charleston, 58 Coming St., Charleston, SC 29424, USA
¹¹ Universitäts-Sternwarte München, Ludwig-Maximilians- Universität, Scheinerstr. 1, 81679 München, Germany
¹² Exoplanets and Stellar Astrophysics Laboratory, Code 667, Goddard Space Flight Center, Greenbelt, MD 20771, USA
¹³ Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002, USA
¹⁴ Goddard Center for Astrobiology, USA
¹⁵ National Astronomical Observatory of Japan, Mitaka, 181-8588 Tokyo, Japan
¹⁶ Institute for Astronomy, University of Hawaii, 640 N. A’ohoku Place, Hilo, HI 96720, USA
¹⁷ Department of Astronomy, Stockholm University, AlbaNova University Center, 106 91 Stockholm, Sweden
¹⁸ Department of Astrophysical Science, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544, USA
¹⁹ Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, 152-8551 Tokyo, Japan
²⁰ Department of Astronomy, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-0033 Tokyo, Japan
²¹ Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyamacho, Toyonaka, 560-0043 Osaka, Japan
²² Hiroshima University, 1-3-2, Kagamiyama, Higashihiroshima, 739-8511 Hiroshima, Japan
²³ Department of Astrophysics, CAB-CSIC/INTA, 28850 Torrejón de Ardoz, Madrid, Spain
²⁴ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
²⁵ Department of Astronomical Science, The Graduate University for Advanced Studies, 2-21-1, Osawa, Mitaka, 181-8588 Tokyo, Japan
²⁶ Institute of Astronomy and Astrophysics, Academia Sinica, PO Box 23-141, Taipei 10617, Taiwan
²⁷ Swiss Federal Institute of Technology (ETH Zurich), Institute for Astronomy, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland
²⁸ Kavli Institute for Physics and Mathematics of the Universe, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa,277-8568 Chiba, Japan
²⁹ Department of Cosmosciences, Hokkaido University, Kita-ku, Sapporo, 060-0810 Hokkaido, Japan
³⁰ H. L. Dodge Department of Physics & Astronomy, University of Oklahoma, 440 W Brooks St Norman, OK 73019, USA
³¹ Astronomical Institute, Tohoku University, Aoba-ku, Sendai, 980-8578 Miyagi, Japan
³² The Center for the Promotion of Integrated Sciences, The Graduate University for Advanced Studies (SOKENDAI), Shonan International Village, Hayama-cho, Miura-gun, 240-0193 Kanagawa, Japan
³³ Department of Astronomical Science, The Graduate University for Advanced Studies (SOKENDAI), 2-21-1 Osawa, Mitaka, 181-8588 Tokyo, Japan
³⁴ Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Kanagawa, Japan

Received: 12 April 2016
Accepted: 30 September 2016

Abstract

We present H-band (1.6 μm) scattered light observations of the transitional disk RX J1615.3-3255, located in the ~1 Myr old Lupus association. From a polarized intensity image, taken with the HiCIAO instrument of the Subaru Telescope, we deduce the position angle and the inclination angle of the disk. The disk is found to extend out to 68 ± 12 AU in scattered light and no clear structure is observed. Our inner working angle of 24 AU does not allow us to detect a central decrease in intensity similar to that seen at 30 AU in the 880 μm continuum observations. We compare the observations with multiple disk models based on the spectral energy distribution (SED) and submm interferometry and find that an inner rim of the outer disk at 30 AU containing small silicate grains produces a polarized intensity signal which is an order of magnitude larger than observed. We show that a model in which the small dust grains extend smoothly into the cavity found for large grains is closer to the actual H-band observations. A comparison of models with different dust size distributions suggests that the dust in the disk might have undergone significant processing compared to the interstellar medium.