Multi-epoch Direct Imaging and Time-Variable Scattered Light Morphology of the HD 163296 Protoplanetary Disk
Creators: name: Rich, Evan A.
name: Wisniewski, John P.
name: Currie, Thayne
name: Fukagawa, Misato
name: Grady, Carol A.
name: Sitko, Michael L.
name: Pikhartova, Monika
name: Hashimoto, Jun
name: Abe, Lyu
name: Brandner, Wolfgang
name: Brandt, Timothy D.
name: Carson, Joseph C.
name: Chilcote, Jeffrey
name: Dong, Ruobing
name: Feldt, Markus
name: Goto, Miwa
name: Groff, Tyler
name: Guyon, Olivier
name: Hayano, Yutaka
name: Hayashi, Masahiko
name: Hayashi, Saeko S.
name: Henning, Thomas
name: Hodapp, Klaus W.
name: Ishii, Miki
name: Iye, Masanori
name: Janson, Markus
name: Jovanovic, Nemanja
name: Kandori, Ryo
name: Kasdin, Jeremy
name: Knapp, Gillian R.
name: Kudo, Tomoyuki
name: Kusakabe, Nobuhiko
name: Kuzuhara, Masayuki
name: Kwon, Jungmi
name: Lozi, Julien
name: Martinache, Frantz
name: Matsuo, Taro
name: Mayama, Satoshi
name: McElwain, Michael W.
name: Miyama, Shoken
name: Morino, Jun-Ichi
name: Moro-Martin, Amaya
name: Nakagawa, Takao
name: Nishimura, Tetsuo
name: Pyo, Tae-Soo
name: Serabyn, Eugene
name: Suto, Hiroshi
name: Russel, Ray W.
name: Suzuki, Ryuji
name: Takami, Michihiro
name: Takato, Naruhisa
name: Terada, Hiroshi
name: Thalmann, Christian
name: Turner, Edwin L.
name: Uyama, Taichi
name: Wagner, Kevin R.
name: Watanabe, Makoto
name: Yamada, Toru
name: Takami, Hideki
name: Usuda, Tomonori
name: Tamura, Motohide
Publisher: name: arXiv
Year: 2018
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present H-band polarized scattered light imagery and JHK high-contrast spectroscopy of the protoplanetary disk around HD 163296 observed with the HiCIAO and SCExAO/CHARIS instruments at Subaru Observatory. The polarimetric imagery resolve a broken ring structure surrounding HD 163296 that peaks at a distance along the major axis of 0.65 (66 AU) and extends out to 0.98 (100 AU) along the major axis. Our 2011 H-band data exhibit clear axisymmetry, with the NW- and SE- side of the disk exhibiting similar intensities. Our data are clearly different than 2016 epoch H-band observations from VLT/SPHERE that found a strong 2.7x asymmetry between the NW- and SE-side of the disk. Collectively, these results indicate the presence of time variable, non-azimuthally symmetric illumination of the outer disk. Based on our 3D-MCRT modeling of contemporaneous IR spectroscopic and H-band polarized intensity imagery of the system, we suggest that while the system could plausibly host an inclined inner disk component, such a component is unlikely to be responsible for producing the observed time-dependent azimuthal variations in the outer scattered light disk of the system. While our SCExAO/CHARIS data are sensitive enough to recover the planet candidate identified from NIRC2 in the thermal IR, we fail to detect an object with a corresponding JHK brightness estimated from the atmospheric models of Baraffe et al. 2003. This suggests that the candidate is either fainter in JHK bands than model predictions, possibly due to extinction from the disk or atmospheric dust/clouds, or that it is an artifact of the dataset/data processing. Our SCExAO/CHARIS data lower the IR mass limits for planets inferred at larger stellocentric separations; however, these ALMA-predicted protoplanet candidates are currently still consistent with direct imaging constraints.
description: 19 pages, 13 figures, 2 tables